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Can drive letters and Mount point co-exist together in cluster?

    Question

  • Hi,

    We have sql server 2008 R2 on a 2 node active-passive cluster on Windows server 2008 R2 with 2 CPU & 16GB memory

    We used 10 drive letters for one single instance as below

    C: OS
    D:CD-ROM
    E: Primary data files
    F: Secondary data files
    G:Log
    H:Tempdb data
    I: Tempdblog
    Q:quorum
    Y: Msdtc
    Z: Backups

    Now, we want to install a new instance on the same active node and with Mount poinst.

    Is having mix of drive letters and Mount points in a single cluster supported?

    What is the best practice?

    We want to follow the below steps:

    1. Create new mount point1 for instance 2 (call the root drive as J and install the 2nd instance)

    2. Create Mount point2 (call the root drive as k) for the existing instance which is using Drive letters and then detach 
    user databases and attach databases from drive letters to Mount point2 

    How to deal with SYSTEM Databases in above case (moving from Drive letter to new Mount Points)?

    Please advice me the best approaches to achieve this..

    Thanks 

    Tuesday, March 13, 2012 8:32 PM

Answers

  • I've worked with a few clusters that are using mount points heavily and have run into a few gotchas. It's the only way to go if you are going to really scale out but it takes some getting used to. There is no issue putting your system databases on the VMP's as long as they are in folders, the migration is the same as a normal system DB migration. I don't know about filestream.

    Before you do anything else, read Cindy Gross's article and then read the other links as well:
    http://blogs.msdn.com/b/cindygross/archive/2011/07/05/using-mount-points-with-sql-server.aspx

    Here are some tips off the top of my head.

    1. Folder permissions do not propagate to disk permissions for the mount point. This causes some weird headaches when you're trying to install SQL to a mount point or create databases depending on how high UAC is turned up.

    2. Avoid putting data at the root of the mount point OR on the drive itself. Create folders in the mount points and put all your data in the folders.

    3. Monitoring disk space is tricky. It's exposed through WMI so any tools that speak WMI can get the info, but it can be a challenge. Another GREAT way to go is Utility Control Point. Note that the xp_fixeddrives procedure returns the drive space for the root! There are a lot of installer packages (BES 5.0 comes to mind) that check for disk space before creating the database using that (unsupported) stored procedure and will fail if the root is very small (per another best practice to set your mount point roots to as small as 5MB)

    Hope that helps! Good luck!


    Please click "Propose As Answer" if a post solves your problem or "Vote As Helpful" if a post has been useful to you.

    • Marked as answer by Peja Tao Tuesday, April 10, 2012 2:22 AM
    Tuesday, April 03, 2012 7:46 AM

All replies

  • Hi!

    The simple answer: Yes, it is. And I believe it is even necessary, as my last knowledge was that the root volume (drive letter) needs to be a shared disk and you can present the mountpoints only on this shared disk. So what I would do is have one drive letter per instance and do your mount point below that.

    Lucifer

    • Proposed as answer by Peja Tao Thursday, March 15, 2012 3:26 AM
    Wednesday, March 14, 2012 7:39 AM
  • Is Filestream supports Mount points? Please advice..

    Thanks

    Wednesday, March 14, 2012 3:53 PM
  • Take a look at this post

    http://social.msdn.microsoft.com/Forums/en-US/sqldisasterrecovery/thread/9be32202-52df-4c0e-89f6-2df34f2bc724

    • Proposed as answer by Peja Tao Thursday, March 15, 2012 3:26 AM
    Wednesday, March 14, 2012 4:28 PM
  • I've worked with a few clusters that are using mount points heavily and have run into a few gotchas. It's the only way to go if you are going to really scale out but it takes some getting used to. There is no issue putting your system databases on the VMP's as long as they are in folders, the migration is the same as a normal system DB migration. I don't know about filestream.

    Before you do anything else, read Cindy Gross's article and then read the other links as well:
    http://blogs.msdn.com/b/cindygross/archive/2011/07/05/using-mount-points-with-sql-server.aspx

    Here are some tips off the top of my head.

    1. Folder permissions do not propagate to disk permissions for the mount point. This causes some weird headaches when you're trying to install SQL to a mount point or create databases depending on how high UAC is turned up.

    2. Avoid putting data at the root of the mount point OR on the drive itself. Create folders in the mount points and put all your data in the folders.

    3. Monitoring disk space is tricky. It's exposed through WMI so any tools that speak WMI can get the info, but it can be a challenge. Another GREAT way to go is Utility Control Point. Note that the xp_fixeddrives procedure returns the drive space for the root! There are a lot of installer packages (BES 5.0 comes to mind) that check for disk space before creating the database using that (unsupported) stored procedure and will fail if the root is very small (per another best practice to set your mount point roots to as small as 5MB)

    Hope that helps! Good luck!


    Please click "Propose As Answer" if a post solves your problem or "Vote As Helpful" if a post has been useful to you.

    • Marked as answer by Peja Tao Tuesday, April 10, 2012 2:22 AM
    Tuesday, April 03, 2012 7:46 AM