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How to replace a secondary disk? RRS feed

  • Question

  • I've been using WHS since the early days but I confess, I still don't understand how the drive extender works anad whenever I have to manipulate disks, I run into difficulty.

    Case in point: The secondary disk in my home server had a lot of disk errors so I exchanged it for a new disk. Originally, my primary disk was only 80GB so the secondary (1.5TB) disk held most of the server data with the shares duplicated to an external disk. A few months ago, I replaced primary disk and all the shares were duplicated to it.   Concerned about keeping all my old backups (which include systems that no longer exist), I cloned the old secondary disk and put the newly copied disk into my server.   That was clearly not the way to do the replacement because I now have critical file errcor messages for all my shared folders.   The system console tells me that the system is still looking for the old disk and wants me to add the new one to the storage pool.   

    As I understand it, adding the disk to the storage pool will wipe all the cloned data from the disk and I assume that it will re-duplicate the folders that were marked for duplication.   What about the the other data on the disk?  I realize that I can copy the contents of the un-duplicated shares from the failing disk to new shares on the server but what about my old backups?  Are they gone forever?

    Athena

    Friday, January 25, 2013 2:30 PM

Answers

  • The only supported procedure for replacing a storage pool disk other than the system disk (which requires a server recovery as it's supported replacement method) is to add the new disk to the pool, then remove the old disk from the pool. Cloning isn't a supported way of doing the replacement because Windows Home Server doesn't identify the disk by the data on it, but by the interface it's connected through, the disk hardware, and a disk ID which it constructs during the process of adding the disk to the storage pool. Cloning tools can't guarantee to reproduce all the identifiers, and as a result sometimes a cloned disk results in the type of issue you describe.

    Recovery from this condition is most reliably done in the general case by copying all the data off the server, flattening it, and rebuilding it with the new disk. It may also be possible to tweak the registry to get the disk to be recognized as part of the pool, but this isn't guaranteed to work. For the latter, you'd do better to search elsewhere rather than here, but you may find that you'll find a number of different suggested ways to do what's needed, and none of them are quite right for your situation.

    In the case where a failing disk can't be removed from the storage pool, you should read this FAQ, then (after backing up all your data) you should:

    • shut the server down
    • physically remove the failing disk from the server
    • restart the server
    • remove the "missing" disk from the storage pool
    • if needed, add another disk to the pool to allow the server to re-duplicate files

    Regarding the backup database, I advise users not to rely on Windows Home Server as an archival backup solution because of the relative fragility of the backup database (which is a logical result of it's space efficiency). Any damage to any component (file) in the backup database will result in the loss of one or more backups for one or more computers, and depending on the exact component damaged you can potentially lose all backups for all computers.



    I'm not on the WHS team, I just post a lot. :)

    • Marked as answer by Athena.. _ Sunday, January 27, 2013 3:47 PM
    Saturday, January 26, 2013 4:47 PM
    Moderator

All replies

  • You should not need to rely on cloning. WHS stores all duplicated data on two disks so if one fails the data is still on a second disk. When you add a new disk into the storage pool (the disk is wiped) but all duplicated data is copied back to the new disk so you then have two copies again.

    There are articles in the FAQ section that will help you understand. Start with this one:

    http://social.microsoft.com/Forums/en-US/whsfaq/thread/828b438f-5770-4f4b-bf82-b5d2f12e3887


    Phil P.S. If you find my comment helpful or if it answers your question, please mark it as such.

    Friday, January 25, 2013 4:55 PM
  • Well as I tried to explain, I hoped by cloning the disk I could avoid losing backups (and non-duplicated shares) stored on the failing disk. 

    Is there anyway I can use the cloned disk or do I just have to bite the bullet and say goodbye to that data?

    Athena 

    Friday, January 25, 2013 7:01 PM
  • http://social.microsoft.com/Forums/en-US/whsfaq/thread/cf354b5d-b37b-4b7f-a0d5-8e573697777f


    Phil P.S. If you find my comment helpful or if it answers your question, please mark it as such.

    Friday, January 25, 2013 7:58 PM
  • I'm sorry but we're going around in circles here.   The reason I posted my initial query was because searching the board didn't find anything that specifically addressed the problem of replacing a secondary disk.   I understand the process for replacing the primary disk (BTDT) but I wanted to ensure that I would have my old backups available. 

    If there is no way to use the cloned, secondary disk, I'll just add the new disk to the storage pool and regret the loss.  What I didn't want to do, was to go that route and later find that I could have recovered that data.

    Athena

    Friday, January 25, 2013 9:17 PM
  • The only supported procedure for replacing a storage pool disk other than the system disk (which requires a server recovery as it's supported replacement method) is to add the new disk to the pool, then remove the old disk from the pool. Cloning isn't a supported way of doing the replacement because Windows Home Server doesn't identify the disk by the data on it, but by the interface it's connected through, the disk hardware, and a disk ID which it constructs during the process of adding the disk to the storage pool. Cloning tools can't guarantee to reproduce all the identifiers, and as a result sometimes a cloned disk results in the type of issue you describe.

    Recovery from this condition is most reliably done in the general case by copying all the data off the server, flattening it, and rebuilding it with the new disk. It may also be possible to tweak the registry to get the disk to be recognized as part of the pool, but this isn't guaranteed to work. For the latter, you'd do better to search elsewhere rather than here, but you may find that you'll find a number of different suggested ways to do what's needed, and none of them are quite right for your situation.

    In the case where a failing disk can't be removed from the storage pool, you should read this FAQ, then (after backing up all your data) you should:

    • shut the server down
    • physically remove the failing disk from the server
    • restart the server
    • remove the "missing" disk from the storage pool
    • if needed, add another disk to the pool to allow the server to re-duplicate files

    Regarding the backup database, I advise users not to rely on Windows Home Server as an archival backup solution because of the relative fragility of the backup database (which is a logical result of it's space efficiency). Any damage to any component (file) in the backup database will result in the loss of one or more backups for one or more computers, and depending on the exact component damaged you can potentially lose all backups for all computers.



    I'm not on the WHS team, I just post a lot. :)

    • Marked as answer by Athena.. _ Sunday, January 27, 2013 3:47 PM
    Saturday, January 26, 2013 4:47 PM
    Moderator
  • Regarding the backup database, I advise users not to rely on Windows Home Server as an archival backup solution because of the relative fragility of the backup database (which is a logical result of it's space efficiency). Any damage to any component (file) in the backup database will result in the loss of one or more backups for one or more computers, and depending on the exact component damaged you can potentially lose all backups for all computers.

    I know that no one at Microsoft cares about this product anymore but I have to say, everytime I have to deal with these disks I'm more impressed by the elegance of the design...which unfortunately, is indeed susceptible to fragility.

    Things started out pretty good.  I used the remove command to disconnect the failing disk and the system automatically copied all the unduplicated data to the primary disk.   When it was finished, I went to the "Computers and Backups" screen in the console and could see the status of all the enrolled systems.   I ran into problems though, when I added the new disk and backup stopped.  Both disks were healthy but the backup task was stopped with "unknown" status for all the systems.  I couldn't restart it so I ended up "Repairing" the system and loosing about half my backups.   As it happened, backups for most of the inactive/dead systems were retained (complete with phantom "no antivirus" messages) but I lost backups for 3 out of 4 of my active systems.   That's not really a big loss, since the active machine that has the most data and and changes most from day to day was retained.   I've lost the initial images for the others but that's not an unrecoverable loss.    All the shared files are just fine.

    Now I just have to backup the shares and figure out why one machine wasn't backed up last night.  

    Thanks to both of you for the explanations.

    Athena


    • Edited by Athena.. _ Sunday, January 27, 2013 3:47 PM
    Sunday, January 27, 2013 3:45 PM