July 10, 2011 at 1:04 am
Hi,
We want to implement Mount points to eliminate the Drive letter limitation in a/p clustered environment and I went through the below from the book
Pro_SQL_Server_2008_Failover_Clustering.pdf
SQL Server 2008 failover clustering still requires drive letters to be used for shared cluster drives with
Windows Server 2008. As with SQL Server 2005, you can use mount points, but they must be mounted
under a drive letter. This is not a limitation of Windows, as mount points have been supported in
clusters since Windows Server 2003, but SQL Server has not yet implemented the ability to use mount
points in a cluster without requiring them to be mounted under a drive letter first. This may be fixed
in the next major release of SQL Server. Check the final feature list to see if it is implemented when
that release is available for use
Question:
Is that mean Drive letter Limitation will be solved by using Mount points or not?
Thanks
July 10, 2011 at 6:47 am
We use mount points on almost all of our clusters because of that reason.
We haven't experienced issues with it over the years.
However, you need to take into account you need to follow up lun usage on an individual basis, in stead of per drive letter.
Powershell can help you with it, as does computermanagement/storage / disk management
ref for powershell: http://powershell.com/cs/media/p/4140.aspx
Johan
Learn to play, play to learn !
Dont drive faster than your guardian angel can fly ...
but keeping both feet on the ground wont get you anywhere :w00t:
- How to post Performance Problems
- How to post data/code to get the best help[/url]
- How to prevent a sore throat after hours of presenting ppt
press F1 for solution, press shift+F1 for urgent solution 😀
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Who am I ? Sometimes this is me but most of the time this is me
July 13, 2011 at 2:24 pm
We were recently told by MS that for Windows 2008 R2 clustering that the drive letter is required for SQL Server.
In SQL 2005 we used Veritas clustering which had no problem with only using mount points... neither did SQL, so I don't know that the quote you have is 100% true.
We had a hard time getting our 2008 R2 cluster working, and MS support made us use a drive letter and we were then able to complete the cluster install and fail over successfully. I don't remember all the details, it's been a while... we modified our build process to use multiple mount points for tempdb, data, log, and backup on a drive and 1 drive in our cluster service group.
I don't like it, but that's what MS told us to do.
~C
Craig Outcalt
July 13, 2011 at 3:01 pm
Hm, I would recommend looking at:
How to configure volume mount points on a Microsoft Cluster Server: http://support.microsoft.com/kb/280297
CEWII
July 13, 2011 at 3:12 pm
Yes, but that is the claim of the first poster's quote... that it is not a windows clustering problem but a problem in SQL Server.
from here: http://msdn.microsoft.com/en-us/library/ms189910.aspx
"
SQL Server supports mount points; the clustered installations of SQL Server are limited to the number of available drive letters. Assuming that you use only one drive letter for the operating system, and all other drive letters are available as normal cluster drives or cluster drives hosting mount points, you are limited to a maximum of 25 instances of SQL Server per failover cluster.
A mounted volume, or mount point, allows you to use a single drive letter to refer to many disks or volumes. If you have a drive letter D: that refers to a regular disk or volume, you can connect or "mount" additional disks or volumes as directories under drive letter D: without the additional disks or volumes requiring drive letters of their own.
Additional mount point considerations for SQL Server failover clustering:
SQL Server Setup requires that the base drive of a mounted drive has an associated drive letter. For failover cluster installations, this base drive must be a clustered drive. Volume GUIDs are not supported in this release.
The base drive, the one with the drive letter, cannot be shared among failover cluster instances. This is a normal restriction for failover clusters, but is not a restriction on stand-alone, multi-instance servers.
Take extra care when setting up your failover cluster to ensure that both the base drive and the mounted disks or volumes are all listed as resources in the resource group. SQL Server Setup validates drive configuration as part of a failover cluster installation.
"
I think this means that each cluster needs a drive letter, but you can mount as many mount points on that drive as you want.
That's what we were told by MS support
~C
Craig Outcalt
July 14, 2011 at 12:04 am
SQLBOT (7/13/2011)
...I think this means that each cluster needs a drive letter, but you can mount as many mount points on that drive as you want....
Indeed.
All luns need to be in the sqlinstance cluster resource (dependencies)
Assing a drive letter to one of the luns and mount the onthers into that drive letter.
We use naming conventions with the mounting so we see in the drive path we are using a mounted volume because windows filemanager only shows the drive space of the lun which you assigned the drive letter to. ( win2k3 info !)
If also need the mounted volume space info, and I hope you check that on a regular basis, you need to use computermanagement/storage / disk management.
And of course you can rely on your powershell script :w00t:
Johan
Learn to play, play to learn !
Dont drive faster than your guardian angel can fly ...
but keeping both feet on the ground wont get you anywhere :w00t:
- How to post Performance Problems
- How to post data/code to get the best help[/url]
- How to prevent a sore throat after hours of presenting ppt
press F1 for solution, press shift+F1 for urgent solution 😀
Need a bit of Powershell? How about this
Who am I ? Sometimes this is me but most of the time this is me
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