RAID5 for all files?

In the last few months I've run across two places that had all their
files, including both data and logs, on big, fat RAID5 partitions.
In fact, in one place even the OS and pagefile were on RAID5!
Is this, like, a good idea all of a sudden, and nobody told me?
I hautily informed them that putting in separate physical drives for a
RAID1 set for logs, might provide a load/scalability/performance
factor of 2x all by itself. Is it at all likely that this is actually
the case? Just wondering.
Thanks.
Josh
No...Raid 5 still sucks. The baarf web site is still in
operation - http://www.baarf.com/
Logs being separated out on a Raid 1 or Raid 10 is still
recommended - see the Storage Best Practices:
http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/storage-top-10.mspx
-Sue
On Sun, 05 Aug 2007 20:17:18 -0700, JXStern
<JXSternChangeX2R@.gte.net> wrote:

>In the last few months I've run across two places that had all their
>files, including both data and logs, on big, fat RAID5 partitions.
>In fact, in one place even the OS and pagefile were on RAID5!
>Is this, like, a good idea all of a sudden, and nobody told me?
>I hautily informed them that putting in separate physical drives for a
>RAID1 set for logs, might provide a load/scalability/performance
>factor of 2x all by itself. Is it at all likely that this is actually
>the case? Just wondering.
>Thanks.
>Josh
|||As Sue mentions it is still not the best practice to use Raid5 for a busy
OLTP system.
Andrew J. Kelly SQL MVP
"JXStern" <JXSternChangeX2R@.gte.net> wrote in message
news:kd4db35ek3ge7ldau600i4tk7igv6irns6@.4ax.com...
> In the last few months I've run across two places that had all their
> files, including both data and logs, on big, fat RAID5 partitions.
> In fact, in one place even the OS and pagefile were on RAID5!
> Is this, like, a good idea all of a sudden, and nobody told me?
> I hautily informed them that putting in separate physical drives for a
> RAID1 set for logs, might provide a load/scalability/performance
> factor of 2x all by itself. Is it at all likely that this is actually
> the case? Just wondering.
> Thanks.
> Josh
>
|||On Mon, 6 Aug 2007 08:50:20 -0400, "Andrew J. Kelly"
<sqlmvpnooospam@.shadhawk.com> wrote:

>As Sue mentions it is still not the best practice to use Raid5 for a busy
>OLTP system.
And even less good for a busy ETL system building gigabyte tables and
output files?
J.
sql

RAID5 for all files?

In the last few months I've run across two places that had all their
files, including both data and logs, on big, fat RAID5 partitions.
In fact, in one place even the OS and pagefile were on RAID5!
Is this, like, a good idea all of a sudden, and nobody told me?
I hautily informed them that putting in separate physical drives for a
RAID1 set for logs, might provide a load/scalability/performance
factor of 2x all by itself. Is it at all likely that this is actually
the case? Just wondering.
Thanks.
JoshNo...Raid 5 still sucks. The baarf web site is still in
operation - http://www.baarf.com/
Logs being separated out on a Raid 1 or Raid 10 is still
recommended - see the Storage Best Practices:
[url]http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/storage-top-10.mspx[
/url]
-Sue
On Sun, 05 Aug 2007 20:17:18 -0700, JXStern
<JXSternChangeX2R@.gte.net> wrote:

>In the last few months I've run across two places that had all their
>files, including both data and logs, on big, fat RAID5 partitions.
>In fact, in one place even the OS and pagefile were on RAID5!
>Is this, like, a good idea all of a sudden, and nobody told me?
>I hautily informed them that putting in separate physical drives for a
>RAID1 set for logs, might provide a load/scalability/performance
>factor of 2x all by itself. Is it at all likely that this is actually
>the case? Just wondering.
>Thanks.
>Josh|||As Sue mentions it is still not the best practice to use Raid5 for a busy
OLTP system.
Andrew J. Kelly SQL MVP
"JXStern" <JXSternChangeX2R@.gte.net> wrote in message
news:kd4db35ek3ge7ldau600i4tk7igv6irns6@.
4ax.com...
> In the last few months I've run across two places that had all their
> files, including both data and logs, on big, fat RAID5 partitions.
> In fact, in one place even the OS and pagefile were on RAID5!
> Is this, like, a good idea all of a sudden, and nobody told me?
> I hautily informed them that putting in separate physical drives for a
> RAID1 set for logs, might provide a load/scalability/performance
> factor of 2x all by itself. Is it at all likely that this is actually
> the case? Just wondering.
> Thanks.
> Josh
>|||On Mon, 6 Aug 2007 08:50:20 -0400, "Andrew J. Kelly"
<sqlmvpnooospam@.shadhawk.com> wrote:

>As Sue mentions it is still not the best practice to use Raid5 for a busy
>OLTP system.
And even less good for a busy ETL system building gigabyte tables and
output files?
J.

RAID5 for all files?

In the last few months I've run across two places that had all their
files, including both data and logs, on big, fat RAID5 partitions.
In fact, in one place even the OS and pagefile were on RAID5!
Is this, like, a good idea all of a sudden, and nobody told me?
I hautily informed them that putting in separate physical drives for a
RAID1 set for logs, might provide a load/scalability/performance
factor of 2x all by itself. Is it at all likely that this is actually
the case? Just wondering. :)
Thanks.
JoshNo...Raid 5 still sucks. The baarf web site is still in
operation - http://www.baarf.com/
Logs being separated out on a Raid 1 or Raid 10 is still
recommended - see the Storage Best Practices:
http://www.microsoft.com/technet/prodtechnol/sql/bestpractice/storage-top-10.mspx
-Sue
On Sun, 05 Aug 2007 20:17:18 -0700, JXStern
<JXSternChangeX2R@.gte.net> wrote:
>In the last few months I've run across two places that had all their
>files, including both data and logs, on big, fat RAID5 partitions.
>In fact, in one place even the OS and pagefile were on RAID5!
>Is this, like, a good idea all of a sudden, and nobody told me?
>I hautily informed them that putting in separate physical drives for a
>RAID1 set for logs, might provide a load/scalability/performance
>factor of 2x all by itself. Is it at all likely that this is actually
>the case? Just wondering. :)
>Thanks.
>Josh|||As Sue mentions it is still not the best practice to use Raid5 for a busy
OLTP system.
--
Andrew J. Kelly SQL MVP
"JXStern" <JXSternChangeX2R@.gte.net> wrote in message
news:kd4db35ek3ge7ldau600i4tk7igv6irns6@.4ax.com...
> In the last few months I've run across two places that had all their
> files, including both data and logs, on big, fat RAID5 partitions.
> In fact, in one place even the OS and pagefile were on RAID5!
> Is this, like, a good idea all of a sudden, and nobody told me?
> I hautily informed them that putting in separate physical drives for a
> RAID1 set for logs, might provide a load/scalability/performance
> factor of 2x all by itself. Is it at all likely that this is actually
> the case? Just wondering. :)
> Thanks.
> Josh
>|||On Mon, 6 Aug 2007 08:50:20 -0400, "Andrew J. Kelly"
<sqlmvpnooospam@.shadhawk.com> wrote:
>As Sue mentions it is still not the best practice to use Raid5 for a busy
>OLTP system.
And even less good for a busy ETL system building gigabyte tables and
output files?
J.

Raid5 and Suspect DB

I have a DB on a Raid 5 of 4 disks. One of the disks failed, freezed the
screen and everything else,
I was obliged to reboot
After reboot, My DB was in suspectmode, First question, if I am not
mistaken, as far as it is raid 5, the DB must not be in suspect mode
Ok, I used the last good full backup, DB came back on line. 2 hours or more
the same thing happened.
I wonder what is the efficiency of RAID 5
Perhaps the database was exactly in the middle of IOs and the Raid did not
cover it...Was the Raid array continuously available?
Asingle disk failure on Raid 5 should not have affected anything.
Wayne Snyder, MCDBA, SQL Server MVP
Mariner, Charlotte, NC
www.mariner-usa.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
www.sqlpass.org
"SalamElias" <eliassal@.online.nospam> wrote in message
news:C7D83256-BDCA-41D4-A45C-214CF0F47202@.microsoft.com...
> I have a DB on a Raid 5 of 4 disks. One of the disks failed, freezed the
> screen and everything else,
> I was obliged to reboot
> After reboot, My DB was in suspectmode, First question, if I am not
> mistaken, as far as it is raid 5, the DB must not be in suspect mode
> Ok, I used the last good full backup, DB came back on line. 2 hours or
more
> the same thing happened.
> I wonder what is the efficiency of RAID 5
|||Thanks for your response, when you say DB was in the middle of IOs, I
understand when reading Books on line or any other docs regarding DBs
recovery plan should be able to handle these events (rol back or roll forward
in case of disk failure. AmI mistaken?
I confirm it wa a one disk failure. Also one more strange thing happened, I
changed the faulty disk, deleted the database, tried to recreate it, It was
not possible (got error messages). I changed the physical datafile place (on
the raid 0 log disk), DB was created. Any ideas or thoughts.
Thanks again
"Wayne Snyder" wrote:

> Perhaps the database was exactly in the middle of IOs and the Raid did not
> cover it...Was the Raid array continuously available?
> Asingle disk failure on Raid 5 should not have affected anything.
> --
> Wayne Snyder, MCDBA, SQL Server MVP
> Mariner, Charlotte, NC
> www.mariner-usa.com
> (Please respond only to the newsgroups.)
> I support the Professional Association of SQL Server (PASS) and it's
> community of SQL Server professionals.
> www.sqlpass.org
> "SalamElias" <eliassal@.online.nospam> wrote in message
> news:C7D83256-BDCA-41D4-A45C-214CF0F47202@.microsoft.com...
> more
>
>

Raid5 and Suspect DB

I have a DB on a Raid 5 of 4 disks. One of the disks failed, freezed the
screen and everything else,
I was obliged to reboot
After reboot, My DB was in suspectmode, First question, if I am not
mistaken, as far as it is raid 5, the DB must not be in suspect mode
Ok, I used the last good full backup, DB came back on line. 2 hours or more
the same thing happened.
I wonder what is the efficiency of RAID 5Perhaps the database was exactly in the middle of IOs and the Raid did not
cover it...Was the Raid array continuously available?
Asingle disk failure on Raid 5 should not have affected anything.
Wayne Snyder, MCDBA, SQL Server MVP
Mariner, Charlotte, NC
www.mariner-usa.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
www.sqlpass.org
"SalamElias" <eliassal@.online.nospam> wrote in message
news:C7D83256-BDCA-41D4-A45C-214CF0F47202@.microsoft.com...
> I have a DB on a Raid 5 of 4 disks. One of the disks failed, freezed the
> screen and everything else,
> I was obliged to reboot
> After reboot, My DB was in suspectmode, First question, if I am not
> mistaken, as far as it is raid 5, the DB must not be in suspect mode
> Ok, I used the last good full backup, DB came back on line. 2 hours or
more
> the same thing happened.
> I wonder what is the efficiency of RAID 5|||Thanks for your response, when you say DB was in the middle of IOs, I
understand when reading Books on line or any other docs regarding DBs
recovery plan should be able to handle these events (rol back or roll forwar
d
in case of disk failure. AmI mistaken?
I confirm it wa a one disk failure. Also one more strange thing happened, I
changed the faulty disk, deleted the database, tried to recreate it, It was
not possible (got error messages). I changed the physical datafile place (on
the raid 0 log disk), DB was created. Any ideas or thoughts.
Thanks again
"Wayne Snyder" wrote:

> Perhaps the database was exactly in the middle of IOs and the Raid did not
> cover it...Was the Raid array continuously available?
> Asingle disk failure on Raid 5 should not have affected anything.
> --
> Wayne Snyder, MCDBA, SQL Server MVP
> Mariner, Charlotte, NC
> www.mariner-usa.com
> (Please respond only to the newsgroups.)
> I support the Professional Association of SQL Server (PASS) and it's
> community of SQL Server professionals.
> www.sqlpass.org
> "SalamElias" <eliassal@.online.nospam> wrote in message
> news:C7D83256-BDCA-41D4-A45C-214CF0F47202@.microsoft.com...
> more
>
>

RAID1 vs RAID5 for transaction log

I was hoping that someone could point me to some good documentation on
selecting an optimum RAID configuration. While performing heavy updates
during upgrades - I've noticed dramatic performance difference between RAID
1 and RAID 5 for the transaction log.
It seems that it is less important for the data files themselves (RAID 5
doesn't seem to hurt that much).
Does this make sense where the RAID Configuration for the T-Log is more
important than the Data?
If someone could shed some light on this or point me to some good
documantation - I would greatly appreciate it.
Thanks in advance
Raid 5 performs very poorly on writes as does hp/compaq's ADG (Advanced data
guarding).
If your database is mainly reads then raid 5 is ok for the datafiles.
Also consider that if a disk fails and the array is having to construct a
phantom disk on the fly then the performance of your system will probably
make it unusable.
It's worth pulling a disk on a system before it goes live and practice the
recovery.
Personally I use a raid 10 array of 4 disks for my log (and raid 10 arrays
for my data too). A mirror pair may do for your log.
Paul
"TJT" <TJT@.nospam.com> wrote in message
news:uDWYpug5FHA.1248@.TK2MSFTNGP14.phx.gbl...
>I was hoping that someone could point me to some good documentation on
> selecting an optimum RAID configuration. While performing heavy updates
> during upgrades - I've noticed dramatic performance difference between
> RAID
> 1 and RAID 5 for the transaction log.
> It seems that it is less important for the data files themselves (RAID 5
> doesn't seem to hurt that much).
> Does this make sense where the RAID Configuration for the T-Log is more
> important than the Data?
> If someone could shed some light on this or point me to some good
> documantation - I would greatly appreciate it.
> Thanks in advance
>
|||I've always found this website to be a good RAID level overview (even
though it's a vendor website):
http://www.acnc.com/raid.html
It's not very detailed, just brief pros & cons and how the RAID level is
constructed, but it's good info nonetheless.
*mike hodgson*
blog: http://sqlnerd.blogspot.com
TJT wrote:

>I was hoping that someone could point me to some good documentation on
>selecting an optimum RAID configuration. While performing heavy updates
>during upgrades - I've noticed dramatic performance difference between RAID
>1 and RAID 5 for the transaction log.
>It seems that it is less important for the data files themselves (RAID 5
>doesn't seem to hurt that much).
>Does this make sense where the RAID Configuration for the T-Log is more
>important than the Data?
>If someone could shed some light on this or point me to some good
>documantation - I would greatly appreciate it.
>Thanks in advance
>
>
|||RAID5 is terrible for heavily updated data, and the Transaction Log is the
prototypical worst case. Go for RAID 1. For database files/filegroups it
really depends on the update load. In general the feeling has been that
RAID 10 (aka 1+0) is better for databases since you get maximum performance
and availability. But if you have lightly updated tables then RAID 5 is
going to be OK.
If I remember correctly Kalen Delaney's "Inside SQL Server 2000" book has a
good discussion about this.
Hal Berenson, President
PredictableIT, LLC
www.predictableit.com
"Mike Hodgson" <mike.hodgson@.mallesons.nospam.com> wrote in message
news:e6mn%23ll5FHA.1276@.TK2MSFTNGP09.phx.gbl...
> I've always found this website to be a good RAID level overview (even
> though it's a vendor website):
> http://www.acnc.com/raid.html
> It's not very detailed, just brief pros & cons and how the RAID level is
> constructed, but it's good info nonetheless.
> --
> *mike hodgson*
> blog: http://sqlnerd.blogspot.com
>
> TJT wrote:
>
sql

RAID1 vs RAID5 for transaction log

I was hoping that someone could point me to some good documentation on
selecting an optimum RAID configuration. While performing heavy updates
during upgrades - I've noticed dramatic performance difference between RAID
1 and RAID 5 for the transaction log.
It seems that it is less important for the data files themselves (RAID 5
doesn't seem to hurt that much).
Does this make sense where the RAID Configuration for the T-Log is more
important than the Data?
If someone could shed some light on this or point me to some good
documantation - I would greatly appreciate it.
Thanks in advanceRaid 5 performs very poorly on writes as does hp/compaq's ADG (Advanced data
guarding).
If your database is mainly reads then raid 5 is ok for the datafiles.
Also consider that if a disk fails and the array is having to construct a
phantom disk on the fly then the performance of your system will probably
make it unusable.
It's worth pulling a disk on a system before it goes live and practice the
recovery.
Personally I use a raid 10 array of 4 disks for my log (and raid 10 arrays
for my data too). A mirror pair may do for your log.
Paul
"TJT" <TJT@.nospam.com> wrote in message
news:uDWYpug5FHA.1248@.TK2MSFTNGP14.phx.gbl...
>I was hoping that someone could point me to some good documentation on
> selecting an optimum RAID configuration. While performing heavy updates
> during upgrades - I've noticed dramatic performance difference between
> RAID
> 1 and RAID 5 for the transaction log.
> It seems that it is less important for the data files themselves (RAID 5
> doesn't seem to hurt that much).
> Does this make sense where the RAID Configuration for the T-Log is more
> important than the Data?
> If someone could shed some light on this or point me to some good
> documantation - I would greatly appreciate it.
> Thanks in advance
>|||I've always found this website to be a good RAID level overview (even
though it's a vendor website):
http://www.acnc.com/raid.html
It's not very detailed, just brief pros & cons and how the RAID level is
constructed, but it's good info nonetheless.
*mike hodgson*
blog: http://sqlnerd.blogspot.com
TJT wrote:

>I was hoping that someone could point me to some good documentation on
>selecting an optimum RAID configuration. While performing heavy updates
>during upgrades - I've noticed dramatic performance difference between RAID
>1 and RAID 5 for the transaction log.
>It seems that it is less important for the data files themselves (RAID 5
>doesn't seem to hurt that much).
>Does this make sense where the RAID Configuration for the T-Log is more
>important than the Data?
>If someone could shed some light on this or point me to some good
>documantation - I would greatly appreciate it.
>Thanks in advance
>
>|||RAID5 is terrible for heavily updated data, and the Transaction Log is the
prototypical worst case. Go for RAID 1. For database files/filegroups it
really depends on the update load. In general the feeling has been that
RAID 10 (aka 1+0) is better for databases since you get maximum performance
and availability. But if you have lightly updated tables then RAID 5 is
going to be OK.
If I remember correctly Kalen Delaney's "Inside SQL Server 2000" book has a
good discussion about this.
Hal Berenson, President
PredictableIT, LLC
www.predictableit.com
"Mike Hodgson" <mike.hodgson@.mallesons.nospam.com> wrote in message
news:e6mn%23ll5FHA.1276@.TK2MSFTNGP09.phx.gbl...
> I've always found this website to be a good RAID level overview (even
> though it's a vendor website):
> http://www.acnc.com/raid.html
> It's not very detailed, just brief pros & cons and how the RAID level is
> constructed, but it's good info nonetheless.
> --
> *mike hodgson*
> blog: http://sqlnerd.blogspot.com
>
> TJT wrote:
>
>

RAID1 vs RAID5 for transaction log

I was hoping that someone could point me to some good documentation on
selecting an optimum RAID configuration. While performing heavy updates
during upgrades - I've noticed dramatic performance difference between RAID
1 and RAID 5 for the transaction log.
It seems that it is less important for the data files themselves (RAID 5
doesn't seem to hurt that much).
Does this make sense where the RAID Configuration for the T-Log is more
important than the Data?
If someone could shed some light on this or point me to some good
documantation - I would greatly appreciate it.
Thanks in advanceRaid 5 performs very poorly on writes as does hp/compaq's ADG (Advanced data
guarding).
If your database is mainly reads then raid 5 is ok for the datafiles.
Also consider that if a disk fails and the array is having to construct a
phantom disk on the fly then the performance of your system will probably
make it unusable.
It's worth pulling a disk on a system before it goes live and practice the
recovery.
Personally I use a raid 10 array of 4 disks for my log (and raid 10 arrays
for my data too). A mirror pair may do for your log.
Paul
"TJT" <TJT@.nospam.com> wrote in message
news:uDWYpug5FHA.1248@.TK2MSFTNGP14.phx.gbl...
>I was hoping that someone could point me to some good documentation on
> selecting an optimum RAID configuration. While performing heavy updates
> during upgrades - I've noticed dramatic performance difference between
> RAID
> 1 and RAID 5 for the transaction log.
> It seems that it is less important for the data files themselves (RAID 5
> doesn't seem to hurt that much).
> Does this make sense where the RAID Configuration for the T-Log is more
> important than the Data?
> If someone could shed some light on this or point me to some good
> documantation - I would greatly appreciate it.
> Thanks in advance
>|||This is a multi-part message in MIME format.
--060704050306020201010502
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
I've always found this website to be a good RAID level overview (even
though it's a vendor website):
http://www.acnc.com/raid.html
It's not very detailed, just brief pros & cons and how the RAID level is
constructed, but it's good info nonetheless.
--
*mike hodgson*
blog: http://sqlnerd.blogspot.com
TJT wrote:
>I was hoping that someone could point me to some good documentation on
>selecting an optimum RAID configuration. While performing heavy updates
>during upgrades - I've noticed dramatic performance difference between RAID
>1 and RAID 5 for the transaction log.
>It seems that it is less important for the data files themselves (RAID 5
>doesn't seem to hurt that much).
>Does this make sense where the RAID Configuration for the T-Log is more
>important than the Data?
>If someone could shed some light on this or point me to some good
>documantation - I would greatly appreciate it.
>Thanks in advance
>
>
--060704050306020201010502
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
<tt>I've always found this website to be a good RAID level overview
(even though it's a vendor website):<br>
<a class="moz-txt-link-freetext" href="http://links.10026.com/?link=http://www.acnc.com/raid.html</a><br>">http://www.acnc.com/raid.html">http://www.acnc.com/raid.html</a><br>
<br>
It's not very detailed, just brief pros & cons and how the RAID
level is constructed, but it's good info nonetheless.<br>
</tt>
<div class="moz-signature">
<title></title>
<meta http-equiv="Content-Type" content="text/html; ">
<p><span lang="en-au"><font face="Tahoma" size="2">--<br>
</font></span> <b><span lang="en-au"><font face="Tahoma" size="2">mike
hodgson</font></span></b><span lang="en-au"><br>
<font face="Tahoma" size="2">blog:</font><font face="Tahoma" size="2"> <a
href="http://links.10026.com/?link=http://sqlnerd.blogspot.com</a></font></span>">http://sqlnerd.blogspot.com">http://sqlnerd.blogspot.com</a></font></span>
</p>
</div>
<br>
<br>
TJT wrote:
<blockquote cite="miduDWYpug5FHA.1248@.TK2MSFTNGP14.phx.gbl" type="cite">
<pre wrap="">I was hoping that someone could point me to some good documentation on
selecting an optimum RAID configuration. While performing heavy updates
during upgrades - I've noticed dramatic performance difference between RAID
1 and RAID 5 for the transaction log.
It seems that it is less important for the data files themselves (RAID 5
doesn't seem to hurt that much).
Does this make sense where the RAID Configuration for the T-Log is more
important than the Data?
If someone could shed some light on this or point me to some good
documantation - I would greatly appreciate it.
Thanks in advance
</pre>
</blockquote>
</body>
</html>
--060704050306020201010502--|||RAID5 is terrible for heavily updated data, and the Transaction Log is the
prototypical worst case. Go for RAID 1. For database files/filegroups it
really depends on the update load. In general the feeling has been that
RAID 10 (aka 1+0) is better for databases since you get maximum performance
and availability. But if you have lightly updated tables then RAID 5 is
going to be OK.
If I remember correctly Kalen Delaney's "Inside SQL Server 2000" book has a
good discussion about this.
--
Hal Berenson, President
PredictableIT, LLC
www.predictableit.com
"Mike Hodgson" <mike.hodgson@.mallesons.nospam.com> wrote in message
news:e6mn%23ll5FHA.1276@.TK2MSFTNGP09.phx.gbl...
> I've always found this website to be a good RAID level overview (even
> though it's a vendor website):
> http://www.acnc.com/raid.html
> It's not very detailed, just brief pros & cons and how the RAID level is
> constructed, but it's good info nonetheless.
> --
> *mike hodgson*
> blog: http://sqlnerd.blogspot.com
>
> TJT wrote:
>>I was hoping that someone could point me to some good documentation on
>>selecting an optimum RAID configuration. While performing heavy updates
>>during upgrades - I've noticed dramatic performance difference between
>>RAID
>>1 and RAID 5 for the transaction log.
>>It seems that it is less important for the data files themselves (RAID 5
>>doesn't seem to hurt that much).
>>Does this make sense where the RAID Configuration for the T-Log is more
>>important than the Data?
>>If someone could shed some light on this or point me to some good
>>documantation - I would greatly appreciate it.
>>Thanks in advance
>>
>>
>

RAID1 vs 3-disk RAID5 for DB

I'm making whatever hardware upgrades I can very easily do on this box.

Due to only having 6 HDD slots in my IBM x235 tower's backplane, I can't have 3 volumes AND have one of them as RAID 5. Also; a 3 volume RAID 5 just seems silly. Wouldn't it have worse performance than mirrored (both read and write)? Well; I don't claim any knowledge on all this so should stop on the wild guesses.

My DB is 3GB (+ 2GB log file). It's looking like it may grow up to 5 or 10 GB per year on the very outside, so 140GB for DB should be plenty for years to come.

I just want to keep this upgrade small and simple with zero exposure to upgrade heartache and regret. Therefore; I plan to avoid an O/S or Software rebuild.

My hardware / network guy says upgrading the O/S drive from 10K RPM to a larger 15K RPM drive requires OS reload. He's not entirely sure since he's never done it using this IBM RAID card, but 10K RPM should be fine for the O/S.

Existing:
Internal IBM PCI RAID Controller (not sure model, but decent). All RAID is via hardware controller.

Volume 1 = 10K RPM mirrored SCSI.
Volume 2 = 10K RPM RAID5 with 3 volumes
Slot 6 empty.

Solution 1:
1. 2 volume solution that includes a small RAID 5.

Volume 1 = 10K RPM RAID1 SCSI. (O/S, Log, and DB Backup files)
Volume 2 = 15K RPM RAID6 or RAID5 with 4 disks

2. 3 volume solution

Volume 1 = 10K RPM RAID1 SCSI. (O/S only)
Volume 2 = 15K RPM RAID1 SCSI (for DB only)
Volume 3 = 15K RPM RAID1 SCSI (for Log files only)

I have heard it's better to have log files on a mirrored disk because the I/O tends to be write intensive and contiguous. I don't know how intensive DB I/O is vs. Log File I/O vs. OS I/O. Maybe someone who does could advise me in this matter.

Additional question: Are higher capacity HDDs faster for read/write? Say; comparing 32GB vs. 300GB, the 300GB must be more compressed, so more data would travel over the heads. Yet; the specs don't seem to imply that there's much difference (unless I'm missing something).

Thanks!Hi vich

others will be able to answer - I'm pretty hopeless on hardware. Every so often I try to work my way through this and pick up a little more each time:
http://sql-server-performance.com/Community/forums/t/2337.aspx|||Let me take a stab at this and then let the experts chew me apart...

I would recommend the 3 RAID-1 volumes with a big caveat: make sure you have adequate space on the main data volume. If you don't, and you end up "spilling over" data files onto either the O/S volume or the log volume, you've negated any advantage.

Also, check your channel configuration carefully; you'd like the IO from the data LUNs on a separate channel from the IO for the log files (but definitely separate from the backup LUNs). Usually one SCSI card supports two channels, so you'll probably end up having to compromise something here.

My reasoning:

The OS volume should have the paging file; segregating the I/O for the paging file onto a separate LUN should be a plus;
Having the log files write to a RAID 1 LUN should be a plus; RAID-1 does sequential writes better (when compared to RAID-5);
Provided there's sufficient room, having a RAID-1 LUN for your data should be good; better would be to have more physical spindles for data access (ie, reads), but everything's a compromise in the end.

You did not specify where you were going to write the db backup files in the 3-drive scenario: I would probably go with the OS LUN (again, if it's big enough). Alternatively, if you're network is big enough and reliable enough (and the target is reliable enough), you can write your backups over the network. A LOT of people recommend against this (and with good reason). But if you understand the risks and you are SURE that the network is adequate and the target is reliable, then over the network backups can be a big boost in terms of space saved and IO performance.

Higher capacity drives do not directly affect IO performance. The key metrics for IO performance are RPM and latency. Indirectly however, they do have an impact. Since the new drives are higher cap, the budget guys tend to think you need fewer drives. Fewer drives means fewer spindles. Fewer spindles means slower (read) performance.

Recognizing that not every organization can afford them, I keep pushing SANs, even if it means using some of the lower end systems like the AX 1000 from EMC. Once you break into this world, you'll never want to go back.

Okay, so now everyone can rip into me and show me how ignorant I am!

Regards,

hmscott|||Okay, so now everyone can rip into me and show me how ignorant I am!I had to google LUN :o|||Sounds pretty good to me, hmscott.

In an ideal world, I would want separate spindles for the following objects split off in order of importance:
1) OS/pagefile
2) data filegroups
3) logs
4) tempdb
5) index filegroups

If you have a system that does not do a lot of writing, and mainly reading joined tables, or sorting output, items 3 and 4 invert. Reporting systems love tempdb. If you can not get 5 physical spindles, indexes collapse into the data. If you can not get 4 spindles, try to get tempdb in with the transaction logs. If you only have 2 spindles, hope you have a lightly used system.

Tempdb and transaction logs like having mirror arrays. Data/index filegroups can live with RAID 5, since the write I/O is asynchronous.

EDIT: Cleared up some of the ambiguous pasages.|||Coo - why would you make logs a higher priority on a read heavy system?|||DOH! I renumbered things when I added OS. That should be that tempdb and logs invert, not datafiles and logs invert. Perhaps I should do some editing...|||Sounds pretty good to me, hmscott.

In an ideal world, I would want separate spindles for the following objects split off in order of importance:
1) OS/pagefile
2) data filegroups
3) logs
4) tempdb
5) index filegroups

If you have a system that does not do a lot of writing, and mainly reading joined tables, or sorting output, items 3 and 4 invert. Reporting systems love tempdb. If you can not get 5 physical spindles, indexes collapse into the data. If you can not get 4 spindles, try to get tempdb in with the transaction logs. If you only have 2 spindles, hope you have a lightly used system.

Tempdb and transaction logs like having mirror arrays. Data/index filegroups can live with RAID 5, since the write I/O is asynchronous.

EDIT: Cleared up some of the ambiguous pasages.Great info. Thanks.

So; would I be correct to interpret this as ... having separate spindles for logs + tempdb (ie: 3 spindles rather than just two) should take precedence over putting RAID5 on the Data?

Also; for heavy reporting (I think that's my environment) you clearly say that putting TempDB on a separate spindle is better. But should the Log collapse onto the DB (+ Index) or TempDB spindle? Of any given hour; I would say that only 10 minutes of it actually has a report running somewhere in background. Most of those reports are heavy index users that do not do sorts (Crystal Reports does the sorting - separate processor) so I don't think they use TempDB much. Is there a stock-software simple way to analyze TempDB activity vs. Log activity? My thinking is to combine TempDB and Log files.

I should note: Although we run a fair number of report queries, the non-reporting aspect of the system is more performance critical. Users here wouldn't notice a 100% gain in reporting speed but would find a 200% update / random access slow-down unacceptable.

Your wording almost implies that you don't mind putting Data on a mirror if space allows. My DB is relatively tiny (3GB) so mirrored 72GB drives would be ample. I thought striping actually added performance, albeit hampered by extra processing so only applicable if it's an adequate controller, ergo the popular recommendation of RAID-0 on speed hungry systems not requiring fault tolerance (hard to imagine). Are you saying it's a minor consideration compared with the advantage of spindle separation?

Note: As a humble suggestion, in a high budget system; wouldn't you make a 6th spindle for the OS's swap file? It could be small and cheap, but placing it with the OS would thrash some. Having it's own dedicated spindle would keep the heads in one place and, since it's like-memory storage, it should be as fast as humanly possible.|||If the users are willing to pay the extra $X,000 dollars for the extra spindle, I would certainly not mind using it. Part of this job, however, is to deliver maximum performance at minimum cost. If the existing system shows no signs of disk queues, then most of this is moot. At 3GB most of this database is going to fit in memory, especially if only the last 2 weeks of data are accessed 90% of the time.|||If the users are willing to pay the extra $X,000 dollars for the extra spindle, I would certainly not mind using it. Part of this job, however, is to deliver maximum performance at minimum cost. If the existing system shows no signs of disk queues, then most of this is moot. At 3GB most of this database is going to fit in memory, especially if only the last 2 weeks of data are accessed 90% of the time.
Thanks. They don't mind paying $2.5K for 4 new disks ($650 ea) and $700 for two 1GB RAM sticks. It'll make this box last until next year. It's a safety net for the largely unknown extra load of upcoming MRP - going live next month, and for a $30M company, really, $3K is nothing for a little insurance. They could easily pay the $30K for a new box if it were warranted, but it's not. The larger expense is drawing my time from my larger project, MRP Implementation.

Lots of other hardware boost paths make more sense, but this is the easiest (I think).

My hardware guy will do the actual upgrade. The day before, I'll simply move the DB from E: drive (the RAID 5 volume) to D: drive (Mirrored volume shared by D and C: drives). It'll be a little slow for a day. If it's a disaster; I'll take it down and move back (15 minutes). Then, the next evening (Friday night) he can remove the RAID 5 volume and rebuild those 4 bays however I request.

That box's backplane only has 6 disk bays.

I can either have one 4-disk RAID 5 volume or two RAID 1 volumes.

So; the question on this thread is which one?

With more memory (4GB) plus the boot.ine 3GB switch on; you have a good point that (for the time being) nearly all of the popular pages will always be in memory. So; (DB writes being asynchronous), having slower DB drives will be fine.

Since, in an effort to keep this risk free and simple, we are NOT upgrading the OS volume (C/D), if I go with just a single RAID-5 volume, the more time-critical (synchronous) LOG files will still be on the slower volume.

Going the 3-RAID1-volume route; for the shorter more ongoing index-heavy random IO I'm gambling that they'll usually be using in-memory-pages since the short random reads is where striped volumes help (correct? still fuzzy for me).

Solution 2 is to migrate the DB to our Standy Server, a non-production machine (I use for development). It's the same model (IBM x235) but by a fluke it has 2 processors that are faster (2.6 GHz vs 2.0 GHz), and a faster backplane (although purchased only a month later, IBM had just increased the specs from 400K to 530K). But; it currently only has a single Windows Mirrored volume.

This weekend, when remoted in and fooling around with all this upgrade-option stuff, I discovered it's RAID controller isn't the one my hardware guy thought. It's the 4Lx (see link (http://www-304.ibm.com/jct01004c/systems/support/supportsite.wss/docdisplay?brandind=5000008&lndocid=MIGR-59936)), not the 6M as he thought. Huge difference! So; as of this morning, Solution 2 is looking more attractive. A new RAID controller is another $950, but this (Standby) box (with 15K drives and faster controller), should be at least a 30% overall boost. That would also leave me with a far better standby solution (the old server). Slightly more risk since the OS needs rebuilding.

However; the Standby machine also has the same 6 bay backplane. So I'm stuck with the same Volume choice.

MCrowley - I realize I'm splitting hairs here. Although it is a real upgrade exercise, it's been a wonderful opportunity to display my ignorance, and by doing so, allow some of it to evaporate. :) However; any more "thinking" on this could be considered "playing around". It's really been an education to see the parts in motion, as it were. Well; back to the Application Software side of my job here. I feel more comfortable knowing I at least won't screw things up by eliminating RAID 5. Next year; I'll add a SAS or SAN box if the MRP grinds and expands as I think it will.|||As a caution, I do feel I have to say that learning this stuff is a good thing for you to do. But knowledge, being power, can be dangerous, too (just ask the Sorcerer's Apprentice). I do not know how your shop works, but as a generalism, businesses like to talk about ROI, and results, and other such rubbish. If you spend too much money for no noticeable effect, then the budget for next year may not consider your improvement ideas. It is an almost impossible hole to dig out of, too. Think about it this way. If your doctor prescribes a bunch of pills one week, then a whole new set the next week, and a third set the third week, and you are not feeling any better, how many weeks would you maintain faith in the doctor? This is much more a matter of office politics than technical detail, so your judgment there is going to carry much more weight than I am.|||As a caution, I do feel I have to say that learning this stuff is a good thing for you to do. But knowledge, being power, can be dangerous, too (just ask the Sorcerer's Apprentice). I do not know how your shop works, but as a generalism, businesses like to talk about ROI, and results, and other such rubbish. If you spend too much money for no noticeable effect, then the budget for next year may not consider your improvement ideas. It is an almost impossible hole to dig out of, too. Think about it this way. If your doctor prescribes a bunch of pills one week, then a whole new set the next week, and a third set the third week, and you are not feeling any better, how many weeks would you maintain faith in the doctor? This is much more a matter of office politics than technical detail, so your judgment there is going to carry much more weight than I am.
Thanks. I'm taking that to mean you don't think it's warranted. From a performance standpoint, you may be right. I'm not skilled enough reading Disk performance stats to really know. The upcoming MRP implementation is the motivation. It's well into the 6 digit number already, so $4K for adding 30% to 4 year old servers seems worth the insurance.

However; I'll take your advice and go with migrating the DB to Standby Server. This solution has the added ROI of improving the realistic capability of our Standby Server solution to actually assume the production load in the event of a failure. Coupled with the extra performance (and accompanying extra capacity for Load growth), it's a true ROI. Not ROI they may see, but "they" are in tune with the fact that not all ROIs are visible.

Of course; if I "upgraded" and made things worse by eliminating RAID-5 (ergo, this thread), then I'd (rightly) have a credibility problem.

The way this shop works is that my credibility is very good so they allow me to make all IT decisions, including spending - within a set budget, but they don't hesitate to expand that budget on my say-so. In 4 years, they have never once said "no" nor questioned my word, except as clarification. I've taken that trust to heart. In return; they're very satisfied with how smoothly IT runs itself (so to speak). They happily shell out my rate and give me utmost respect. It's wonderful and I would hate to forfeit that position so safeguarding my credibility is a worthy suggestion. Still; they spend $300K+ on new manufacturing gear, trucks, etc at the drop of a hat. $4K won't even be noticed (unless it buys them grief).

Appreciate all the help.

Raid performance

Hi!
I have a 6xPIII-700 Xeon 4Gb RAM Raid1 (OS) Raid5 (6x18Gb,- data)
Raid1 (logs)
/* all hardware RAID */
The server has ULTRA3 controller with 128Mb read/write cache (50%/50%)
I have this software on the server: Win2k Adv. Server sp4 + MS SQL
2000 sp3.
The total size of databases is about 60Gb.
Recently noticed very large queue for disk on Raid5, it was about
60(Avg. Disk Queue Length counter).
At the same time the Avg. Disk Bytes/Transfer counter was 37015, that
is only 36Kb.
Is it normal or I am having something wrong configured?
These are exact numbers:
Average Minimum Maximum Duration
Avg. Disk
Queue Length 59,281 0 374,205 1:40
Avg. Disk
Bytes/Transfer 37015,042 0,000 90173,594 1:40
These are screenshots:
http://roustam.hotbox.ru/queue_length.jpg
http://roustam.hotbox.ru/disk_transfer.jpg
I guess this can be locale problem. In my locale comma ',' means
fraction, point '.' devides large numbers into 3 digit portions.
Because of mix of locales (the Win2k server is English), comma is used
for both purposes. Perhaps, in this case, the "Avg. Disk
Bytes/Transfer" counter is actualy not 37015 bytes, but 37 015 042
bytes. But "Avg. Disk Queue Length" couter is 59 on the average. This
is only a guess.
Thanks.HI all,
I encountered a problem in SQL Server. Suddenly, my SQL Server stopped and
NT event log generated the entry:
" wait_for_client_connects: Process 2892 generated fatal exception c0000005
EXCEPTION_ACCESS_VIOLATION. SQL Server is terminating this process."
Contents of Exception.log:
--
09/16/03 13:19:51 spid 0 Exception c0000005 E at 0041170b (PvODSMemalloc +
c) reading address 0000000C
09/16/03 13:19:53 spid 0 Exception c0000005 E at 41061eae (IGetFullEvent +
104) writing address 23550000
Contents of dump file:
--
****************************************************************************
**
*
*
* Exception Address = 0041170B (PvODSMemalloc + c)
* Exception Code = c0000005 E
* Access Violation occurred reading address 0000000C
*
* MODULE BASE END SIZE
* sqlservr 00400000 008bbfff 004bc000
* ntdll 77f80000 77ffafff 0007b000
* KERNEL32 77e80000 77f35fff 000b6000
* ADVAPI32 77db0000 77e0cfff 0005d000
* RPCRT4 77d30000 77d9dfff 0006e000
* USER32 77e10000 77e74fff 00065000
* GDI32 77f40000 77f7bfff 0003c000
* ole32 77a50000 77b3bfff 000ec000
* OLEAUT32 779b0000 77a4afff 0009b000
* VERSION 77820000 77826fff 00007000
* LZ32 759b0000 759b5fff 00006000
* opends60 41060000 41085fff 00026000
* ums 41090000 4109cfff 0000d000
*
* Edi: 77E87828: 15ff0424 74ff0008 c2ffffff 7ee80c24 74ff0c24 74ff006a
* Esi: 000D8CD0: 411a105a 411a1069 411a1041 411a1037 411a100a 411a1064
* Eax: 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
* Ebx: 00000003:
* Ecx: 00000000:
* Edx: 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
* Eip: 0041170B: 5d0409b8 660017e5 70850f00 087d8366 ec8b55c3 5d0c51ff
* Ebp: 3FCBFEEC: 22580028 41064131 00000360 22580028 410619d4 22580028
* SegCs: 0000001B:
* EFlags: 00010206: 00730079 0053005c 0054004e 004e0049 0057005c 003a0043
* Esp: 3FCBFEE4: 00000360 22580028 410619d4 22580028 00000360 22580028
* SegSs: 00000023:
****************************************************************************
***
----
--
Short Stack Dump
0x0041170b Module(sqlservr+1170b) (PvODSMemalloc+c)
0x410619d4 Module(opends60+19d4) (srv_allocMO+18)
----
--
Location : 0x0041170b Module(sqlservr+1170b) (PvODSMemalloc+c)
Return Addr: 0x410619d4 Module(opends60+19d4) (srv_allocMO+18)
Frame : 3fcbfeec
Parameters:
[1] 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
[2] 00000360:
[3] 41064131: fe8bc033 000000d8 b9000095 fa840ff3 3b08c483 db33f08b
[4] 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
160 bytes of stack data from 3fcbfe4c to 3fcbfeec
3fcbfe4c: 001132b0 00d70178 00d70178 7ffafbf8 [.2..x...x......]
3fcbfe5c: 00000000 3f730000 00000404 75021166 [.....s?...f..u]
3fcbfe6c: 00102800 7502119d 74fd7560 000003fc [.(....u`u.t...]
3fcbfe7c: 000003f8 000000d4 00000000 00000000 [............]
3fcbfe8c: 000bd6d8 00000048 3fbbf28c 74fd75f5 [...H.....?.u.t]
3fcbfe9c: 00103ca0 000d8d1c 00103830 000db208 [.<.....08.....]
3fcbfeac: 75021100 00000005 75021100 00000000 [...u......u...]
3fcbfebc: 00000000 000bd6d8 00d70178 00d70178 [......x...x...]
3fcbfecc: 00d70178 00d70178 00103830 000d8d1c [x...x...08.....]
3fcbfedc: 000d8d0c 00000000 22580028 00000360 [......(.X"`...]
----
--
Location : 0x410619d4 Module(opends60+19d4) (srv_allocMO+18)
Return Addr: 0x41064131 Module(opends60+4131) (int_InitSrvProc+1c)
Frame : 3fcbfef8
Parameters:
[1] 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
[2] 00000360:
[3] 77E87828: 15ff0424 74ff0008 c2ffffff 7ee80c24 74ff0c24 74ff006a
[4] 000D8CD0: 411a105a 411a1069 411a1041 411a1037 411a100a 411a1064
12 bytes of stack data from 3fcbfeec to 3fcbfef8
3fcbfeec: 22580028 410619d4 22580028 [(.X"...A(.X"]
..........
..........
..........
----
--
Dump thread - spid = 1, PSS = 0x1f82a084, EC = 0x1f82a234
Short Stack Dump
0x77f83786 Module(ntdll+3786) (NtWaitForSingleObject+b)
0x41092d0b Module(ums+2d0b) (UmsThreadScheduler::Switch+56)
0x41091775 Module(ums+1775) (UmsScheduler::Suspend+b2)
0x004c4e6f Module(sqlservr+c4e6f) (GlobalTskMgrProc+14a)
0x41092be1 Module(ums+2be1) (ProcessWorkRequests+ed)
0x4109336a Module(ums+336a) (ThreadStartRoutine+139)
Unable to get thread context for spid 7
Unable to get thread context for spid 8
Any details on this will be more helpful.
Thanks,
Balaji Ragupathi|||Has a Service Pack or HotFix just been applied to the SQL Server...? I
recall a problem post SP install which sounds very similar to what your
experiencing.
--
HTH
Ryan Waight, MCDBA, MCSE
"Balaji Ragupathi" <balajir@.rajasri.com> wrote in message
news:eNDOVTQfDHA.1712@.TK2MSFTNGP11.phx.gbl...
> HI all,
> I encountered a problem in SQL Server. Suddenly, my SQL Server stopped and
> NT event log generated the entry:
> " wait_for_client_connects: Process 2892 generated fatal exception
c0000005
> EXCEPTION_ACCESS_VIOLATION. SQL Server is terminating this process."
> Contents of Exception.log:
> --
> 09/16/03 13:19:51 spid 0 Exception c0000005 E at 0041170b (PvODSMemalloc +
> c) reading address 0000000C
> 09/16/03 13:19:53 spid 0 Exception c0000005 E at 41061eae (IGetFullEvent +
> 104) writing address 23550000
> Contents of dump file:
> --
>
****************************************************************************
> **
> *
> *
> * Exception Address = 0041170B (PvODSMemalloc + c)
> * Exception Code = c0000005 E
> * Access Violation occurred reading address 0000000C
> *
> * MODULE BASE END SIZE
> * sqlservr 00400000 008bbfff 004bc000
> * ntdll 77f80000 77ffafff 0007b000
> * KERNEL32 77e80000 77f35fff 000b6000
> * ADVAPI32 77db0000 77e0cfff 0005d000
> * RPCRT4 77d30000 77d9dfff 0006e000
> * USER32 77e10000 77e74fff 00065000
> * GDI32 77f40000 77f7bfff 0003c000
> * ole32 77a50000 77b3bfff 000ec000
> * OLEAUT32 779b0000 77a4afff 0009b000
> * VERSION 77820000 77826fff 00007000
> * LZ32 759b0000 759b5fff 00006000
> * opends60 41060000 41085fff 00026000
> * ums 41090000 4109cfff 0000d000
> *
> * Edi: 77E87828: 15ff0424 74ff0008 c2ffffff 7ee80c24 74ff0c24 74ff006a
> * Esi: 000D8CD0: 411a105a 411a1069 411a1041 411a1037 411a100a 411a1064
> * Eax: 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
> * Ebx: 00000003:
> * Ecx: 00000000:
> * Edx: 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
> * Eip: 0041170B: 5d0409b8 660017e5 70850f00 087d8366 ec8b55c3 5d0c51ff
> * Ebp: 3FCBFEEC: 22580028 41064131 00000360 22580028 410619d4 22580028
> * SegCs: 0000001B:
> * EFlags: 00010206: 00730079 0053005c 0054004e 004e0049 0057005c 003a0043
> * Esp: 3FCBFEE4: 00000360 22580028 410619d4 22580028 00000360 22580028
> * SegSs: 00000023:
>
****************************************************************************
> ***
> ----
--
> --
> Short Stack Dump
> 0x0041170b Module(sqlservr+1170b) (PvODSMemalloc+c)
> 0x410619d4 Module(opends60+19d4) (srv_allocMO+18)
> ----
--
> --
> Location : 0x0041170b Module(sqlservr+1170b) (PvODSMemalloc+c)
> Return Addr: 0x410619d4 Module(opends60+19d4) (srv_allocMO+18)
> Frame : 3fcbfeec
> Parameters:
> [1] 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
> [2] 00000360:
> [3] 41064131: fe8bc033 000000d8 b9000095 fa840ff3 3b08c483 db33f08b
> [4] 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
> 160 bytes of stack data from 3fcbfe4c to 3fcbfeec
> 3fcbfe4c: 001132b0 00d70178 00d70178 7ffafbf8 [.2..x...x......]
> 3fcbfe5c: 00000000 3f730000 00000404 75021166 [.....s?...f..u]
> 3fcbfe6c: 00102800 7502119d 74fd7560 000003fc [.(....u`u.t...]
> 3fcbfe7c: 000003f8 000000d4 00000000 00000000 [............]
> 3fcbfe8c: 000bd6d8 00000048 3fbbf28c 74fd75f5 [...H.....?.u.t]
> 3fcbfe9c: 00103ca0 000d8d1c 00103830 000db208 [.<.....08.....]
> 3fcbfeac: 75021100 00000005 75021100 00000000 [...u......u...]
> 3fcbfebc: 00000000 000bd6d8 00d70178 00d70178 [......x...x...]
> 3fcbfecc: 00d70178 00d70178 00103830 000d8d1c [x...x...08.....]
> 3fcbfedc: 000d8d0c 00000000 22580028 00000360 [......(.X"`...]
> ----
--
> --
> Location : 0x410619d4 Module(opends60+19d4) (srv_allocMO+18)
> Return Addr: 0x41064131 Module(opends60+4131) (int_InitSrvProc+1c)
> Frame : 3fcbfef8
> Parameters:
> [1] 22580028: 3f800000 00000000 40989800 00000000 0000003e 00000000
> [2] 00000360:
> [3] 77E87828: 15ff0424 74ff0008 c2ffffff 7ee80c24 74ff0c24 74ff006a
> [4] 000D8CD0: 411a105a 411a1069 411a1041 411a1037 411a100a 411a1064
> 12 bytes of stack data from 3fcbfeec to 3fcbfef8
> 3fcbfeec: 22580028 410619d4 22580028 [(.X"...A(.X"]
> ..........
> ..........
> ..........
> ----
--
> --
> Dump thread - spid = 1, PSS = 0x1f82a084, EC = 0x1f82a234
> Short Stack Dump
> 0x77f83786 Module(ntdll+3786) (NtWaitForSingleObject+b)
> 0x41092d0b Module(ums+2d0b) (UmsThreadScheduler::Switch+56)
> 0x41091775 Module(ums+1775) (UmsScheduler::Suspend+b2)
> 0x004c4e6f Module(sqlservr+c4e6f) (GlobalTskMgrProc+14a)
> 0x41092be1 Module(ums+2be1) (ProcessWorkRequests+ed)
> 0x4109336a Module(ums+336a) (ThreadStartRoutine+139)
> Unable to get thread context for spid 7
> Unable to get thread context for spid 8
>
> Any details on this will be more helpful.
> Thanks,
> Balaji Ragupathi
>
>|||I am not sure if the comma is for decimals or not but in either case you
have a disk bottle neck. What is the percentage of reads to writes? You
can monitor disk % for both of these. My guess would be the writes and you
may want to change the controllers cache to be 100% write back and 0% for
read. Sql server does a good job of caching the data for reads and with a
write intensive app you want a lot of write back cache.
Andrew J. Kelly
SQL Server MVP
"Roust_m" <roustam@.hotbox.ru> wrote in message
news:a388fd78.0309170130.5ad407b4@.posting.google.com...
> Hi!
> I have a 6xPIII-700 Xeon 4Gb RAM Raid1 (OS) Raid5 (6x18Gb,- data)
> Raid1 (logs)
> /* all hardware RAID */
> The server has ULTRA3 controller with 128Mb read/write cache (50%/50%)
> I have this software on the server: Win2k Adv. Server sp4 + MS SQL
> 2000 sp3.
> The total size of databases is about 60Gb.
> Recently noticed very large queue for disk on Raid5, it was about
> 60(Avg. Disk Queue Length counter).
> At the same time the Avg. Disk Bytes/Transfer counter was 37015, that
> is only 36Kb.
> Is it normal or I am having something wrong configured?
> These are exact numbers:
> Average Minimum Maximum Duration
> Avg. Disk
> Queue Length 59,281 0 374,205 1:40
> Avg. Disk
> Bytes/Transfer 37015,042 0,000 90173,594 1:40
> These are screenshots:
> http://roustam.hotbox.ru/queue_length.jpg
> http://roustam.hotbox.ru/disk_transfer.jpg
> I guess this can be locale problem. In my locale comma ',' means
> fraction, point '.' devides large numbers into 3 digit portions.
> Because of mix of locales (the Win2k server is English), comma is used
> for both purposes. Perhaps, in this case, the "Avg. Disk
> Bytes/Transfer" counter is actualy not 37015 bytes, but 37 015 042
> bytes. But "Avg. Disk Queue Length" couter is 59 on the average. This
> is only a guess.
>
> Thanks.|||disk queue length should be less than 2 per disk/spindle.
also check avg. disk sec/read which should be in single
digits.
>--Original Message--
>Hi!
>I have a 6xPIII-700 Xeon 4Gb RAM Raid1 (OS) Raid5
(6x18Gb,- data)
>Raid1 (logs)
>/* all hardware RAID */
>The server has ULTRA3 controller with 128Mb read/write
cache (50%/50%)
>I have this software on the server: Win2k Adv. Server sp4
+ MS SQL
>2000 sp3.
>The total size of databases is about 60Gb.
>Recently noticed very large queue for disk on Raid5, it
was about
>60(Avg. Disk Queue Length counter).
>At the same time the Avg. Disk Bytes/Transfer counter was
37015, that
>is only 36Kb.
>Is it normal or I am having something wrong configured?
>These are exact numbers:
> Average Minimum
Maximum Duration
>Avg. Disk
>Queue Length 59,281 0
374,205 1:40
>Avg. Disk
>Bytes/Transfer 37015,042 0,000
90173,594 1:40
>These are screenshots:
>http://roustam.hotbox.ru/queue_length.jpg
>http://roustam.hotbox.ru/disk_transfer.jpg
>I guess this can be locale problem. In my locale
comma ',' means
>fraction, point '.' devides large numbers into 3 digit
portions.
>Because of mix of locales (the Win2k server is English),
comma is used
>for both purposes. Perhaps, in this case, the "Avg. Disk
>Bytes/Transfer" counter is actualy not 37015 bytes, but
37 015 042
>bytes. But "Avg. Disk Queue Length" couter is 59 on the
average. This
>is only a guess.
>
>Thanks.
>.
>sql

RAID Optimal Stripe Size

Hello,
What is the optimal stripe size for RAID10 and RAID5 arrays on Windows 2000
Advanced Server with SQL Server 2000?
Thanks,
Arsen
64K is a good choice for SQL Server because this matches the size of an
extent.
Hope this helps.
Dan Guzman
SQL Server MVP
"Arsen V." <arsen@.community.nospam> wrote in message
news:%23%236sOp1mEHA.3852@.TK2MSFTNGP10.phx.gbl...
> Hello,
> What is the optimal stripe size for RAID10 and RAID5 arrays on Windows
> 2000
> Advanced Server with SQL Server 2000?
> Thanks,
> Arsen
>

RAID Optimal Stripe Size

Hello,
What is the optimal stripe size for RAID10 and RAID5 arrays on Windows 2000
Advanced Server with SQL Server 2000?
Thanks,
Arsen64K is a good choice for SQL Server because this matches the size of an
extent.
--
Hope this helps.
Dan Guzman
SQL Server MVP
"Arsen V." <arsen@.community.nospam> wrote in message
news:%23%236sOp1mEHA.3852@.TK2MSFTNGP10.phx.gbl...
> Hello,
> What is the optimal stripe size for RAID10 and RAID5 arrays on Windows
> 2000
> Advanced Server with SQL Server 2000?
> Thanks,
> Arsen
>