RAID and Cluster!

Hi All, Want to seek advice and experience from all of you. What is the
recommended RAID Solution for SQL Cluster on SAN, is it RAID 1+0 or RAID-5?
We just upgraded from RAID 1+0 to RAID 5 and since then we are getting
hiccups on the Cluster. If there is any connectivity failures on the Drives
(which are recovered after few mins) the Cluster goes haywire and becomes
unavailable (for e.g. it fails to read off the Quorum Log etc...)
Thanks in adv.
Env:
Win2000 Adv Server SP4
SQL2000 SP4
"Vai2000" <nospam@.microsoft.com> wrote in message
news:%23Lb1UxbIGHA.524@.TK2MSFTNGP09.phx.gbl...
> Hi All, Want to seek advice and experience from all of you. What is the
> recommended RAID Solution for SQL Cluster on SAN, is it RAID 1+0 or
RAID-5?
> We just upgraded from RAID 1+0 to RAID 5 and since then we are getting
> hiccups on the Cluster. If there is any connectivity failures on the
Drives
> (which are recovered after few mins) the Cluster goes haywire and becomes
> unavailable (for e.g. it fails to read off the Quorum Log etc...)
>
> Thanks in adv.
>
|||First, you need to fix you SAN issues, with or without clustering SQL really
likes to have its disks online at all times.
Have you separated your Databases and Transaction Log files? RAID 1 or 10
for the Logs. Raid 5 or 10 for the Databases. Quorum & MSDTC (if required)
on its own disk subsystems of 1 GB in size.
Cheers,
Rod
MVP - Windows Server - Clustering
http://www.nw-america.com - Clustering Website
http://msmvps.com/clustering - Blog
http://www.clusterhelp.com - Cluster Training
"Vai2000" <nospam@.microsoft.com> wrote in message
news:%23Lb1UxbIGHA.524@.TK2MSFTNGP09.phx.gbl...
> Hi All, Want to seek advice and experience from all of you. What is the
> recommended RAID Solution for SQL Cluster on SAN, is it RAID 1+0 or
> RAID-5?
> We just upgraded from RAID 1+0 to RAID 5 and since then we are getting
> hiccups on the Cluster. If there is any connectivity failures on the
> Drives
> (which are recovered after few mins) the Cluster goes haywire and becomes
> unavailable (for e.g. it fails to read off the Quorum Log etc...)
>
> Thanks in adv.
>
|||That's not an upgrade, it is a reconfiguration. They do completely
different things. By RAID 1+0 do you mean a stripe of mirrors or a mirror
of stripes?
In either case, the answer is, I don't know. RAID5 gives particular levels
of redundancy while incurring a performance impact for certain types of I/O
patterns. A mirror of stripes gives equivalent redundancy to RAID5 without
having quite a much of a performance impact on certain types of I/O
patterns. A stripe of mirrors gives much greater redundancy than the other
two and generally better performance as well. But, if you are saturating
the I/O channel or stuffing all of your data on a tiny subset of the drives
in the SAN, it really isn't going to matter very much. The recommendations
also vary depending upon whether you have an access pattern that looks like
"tradional OLTP", "traditional DW", or a mix of the two.
Regardless of the performance characteristics, neither one is going to be
more stable than the other in your case. If the SAN drives disconnect, it
doesn't matter if it is a cluster or a standalone SQL Server, it isn't going
to like it. You have to fix the errors on your SAN that are causing the
disconnects first. If those aren't fixed, there isn't anything you are
going to be able to do to make the system stable.
Mike
http://www.solidqualitylearning.com
Disclaimer: This communication is an original work and represents my sole
views on the subject. It does not represent the views of any other person
or entity either by inference or direct reference.
"Vai2000" <nospam@.microsoft.com> wrote in message
news:%23Lb1UxbIGHA.524@.TK2MSFTNGP09.phx.gbl...
> Hi All, Want to seek advice and experience from all of you. What is the
> recommended RAID Solution for SQL Cluster on SAN, is it RAID 1+0 or
> RAID-5?
> We just upgraded from RAID 1+0 to RAID 5 and since then we are getting
> hiccups on the Cluster. If there is any connectivity failures on the
> Drives
> (which are recovered after few mins) the Cluster goes haywire and becomes
> unavailable (for e.g. it fails to read off the Quorum Log etc...)
>
> Thanks in adv.
>
|||Not to mention that unless you have proper host isolation in the SAN, you
are going to run into severe spindle contention, even if this particular
host's channels are not saturated.
Anthony Thomas

"Michael Hotek" <mike@.solidqualitylearning.com> wrote in message
news:%234b0uwdIGHA.676@.TK2MSFTNGP10.phx.gbl...
> That's not an upgrade, it is a reconfiguration. They do completely
> different things. By RAID 1+0 do you mean a stripe of mirrors or a mirror
> of stripes?
> In either case, the answer is, I don't know. RAID5 gives particular
levels
> of redundancy while incurring a performance impact for certain types of
I/O
> patterns. A mirror of stripes gives equivalent redundancy to RAID5
without
> having quite a much of a performance impact on certain types of I/O
> patterns. A stripe of mirrors gives much greater redundancy than the
other
> two and generally better performance as well. But, if you are saturating
> the I/O channel or stuffing all of your data on a tiny subset of the
drives
> in the SAN, it really isn't going to matter very much. The
recommendations
> also vary depending upon whether you have an access pattern that looks
like
> "tradional OLTP", "traditional DW", or a mix of the two.
> Regardless of the performance characteristics, neither one is going to be
> more stable than the other in your case. If the SAN drives disconnect, it
> doesn't matter if it is a cluster or a standalone SQL Server, it isn't
going[vbcol=seagreen]
> to like it. You have to fix the errors on your SAN that are causing the
> disconnects first. If those aren't fixed, there isn't anything you are
> going to be able to do to make the system stable.
> --
> Mike
> http://www.solidqualitylearning.com
> Disclaimer: This communication is an original work and represents my sole
> views on the subject. It does not represent the views of any other person
> or entity either by inference or direct reference.
> "Vai2000" <nospam@.microsoft.com> wrote in message
> news:%23Lb1UxbIGHA.524@.TK2MSFTNGP09.phx.gbl...
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