Backup Media Larger Than 2 TB (GPT Backup Media) RRS feed

  • General discussion

  • Suppose that you have a Windows Home Server 2011 with lots of storage capacity either with or without RAID .  Maybe you also have an external storage device connected to the server using USB or eSATA for backing up the entire server – operating system and data.  Be aware that comfort gained from seeing your complete server backed up daily or even more frequently is falsely based.

    Assume the worst that your server is completely wiped out and you want to restore it using the complete and perfect copy on your external eSATA backup unit.  After all you spent a lot of money and you can see that the server and backup unit are regularly doing their jobs to protect your valuable server contents.  HOWEVER, YOU CANNOT DIRECTLY RESTORE A SERVER FROM A BACKUP DEVICE THAT HAS CAPACITY  LARGER THAT 2 TB!   You must prepare for this worst case scenario with one additional step before disaster hits.

    WinPE (Window Preinstall Environment) that is the basis for the install or recovery DVD has limitations.  It will not recognize GUID Partition Table (GPT) disks which is the basis for large real or virtual disks like your large eSATA backup unit.  Houston, we have a problem!  There is a gap in the restore process between what the restore tool (WinPE) will work with and your backup (a large GPT disk).

    Good news is that there is a relatively simple solution but you must act before disaster strikes to implement it.  Rather than using WinPE to completely restore your server from your large external eSATA backup unit, you must bootstrap the restore in two steps.  In the first step, you need to perform a minimum system restore to get Windows Home Server 2011 back running albeit with none of your data.  Unlike WinPE, Windows Home Server 2011 can recognize the large GPT eSATA drive and restore your valuable data.

    You must create the missing link.  You need what Microsoft calls a “bare metal” backup separate from your large complete system backup.  That bare metal backup must be stored on media that is recognizable by WinPE, i.e. is smaller than 2 TB.  There are three good options:  a small USB hard drive (flash drives don’t work), a Blu-Ray reader/writer, or DVD reader/writer.  DVD is cheaper and a bare metal backup uses only two 4.7 GB discs.  Blu-Ray is more expensive but you don’t have to change discs – the bare metal backup will fit on one disc.  A small USB hard drive is probably best and you can copy RAID drivers (assuming your server uses RAID) to it which will be needed for a restore.

    Windows Home Server 2011 only supports one GUI scheduled backup so you will have to manually create bare metal backups using Windows Server Backup in Server Manager.  You can select the source of your backup – bare metal in this case – and your target storage device.  If you use a small USB hard drive for the bare metal backup, you could leave it attached to the server and run a backup each time you change the server system, e.g. new add-ins or new applications.  Since the bare metal backup does not store any of your data, a new bare metal backup isn’t required for new or changed data.

    Restore involves two steps.  Boot your server from your Microsoft WHS install DVD and select Repair.  Use your bare metal backup on DVD, Blu-Ray disc or USB hard drive to restore the server minimum system with no data.  You now have a sever with an operating system as it was at your last bare metal backup but with no data.  With a minimal WHS now functional, use the Restore function in Server Manager  to restore your data to its original locations. 

    Have fun.


    • Edited by kingair1 Sunday, August 21, 2011 12:49 AM
    Saturday, August 20, 2011 4:56 PM

All replies

  • Given that server backup will only use 2 TB on a disk due to limitations in the underlying storage technology, and also given that a disk connected to the server and configured for backup isn't going to be formatted as a GPT disk, the question of GPT backup disks is rather a non-issue...
    I'm not on the WHS team, I just post a lot. :)
    Saturday, August 20, 2011 9:34 PM
  • A sever will often be comprised of multiple 2 TB disks either real or virtual where the backup from each disk is under 2 TB but the total combined backup is well in excess of 2 TB.  The backup disk will need to be formatted GPT so that it will accept a combined backup larger than 2 TB.  My personal server has 4 x 2 TB hard drives that are organized as two RAID 5 arrays.  The first array, so that it will boot, is 2 TB, formatted MBR, and contains my C: and D: drives (partitions).  The second RAID array which is 4 TB total is formatted GPT subdivided into 2 x 2 TB partitions which form my E: and F: drives.  The entire server, with data well in excess of 2 TB, is backed nicely on an external 4 TB eSATA RAID device formatted GPT.

    In order to confirm the integrety of my system, I have successfully performed the steps in my post above.

    Saturday, August 20, 2011 11:15 PM
  • The backup disk will need to be formatted GPT so that it will accept a combined backup larger than 2 TB.

    My point is that Windows Home Server won't do this for you, and it doesn't need to be done. You can connect multiple disks (each of which will back up less than 2 TB of data) and you can choose the data being backed up to the disk. This is how it's designed to be used, and it works just fine (even for large volumes of data) as long as your source disks are each less than 2 TB. (Above which it doesn't work at all.)

    I will, however, admit that someone with 10/20/30 TB of data is going to have a lot of pain in his future when dealing with backups (that's a lot of backup disks), but the honest truth is that there is no backup solution available today that deals gracefully and inexpensively with that volume of data.

    I'm not on the WHS team, I just post a lot. :)
    Saturday, August 20, 2011 11:46 PM
  • Good point!  However, there are two issues here to consider.  Mechanical (housing and powering multiple backup drives) and the logical aspect of compatibility.  Perhaps one way to address your point but still address the tidiness issue is to use an external device configured with enough 2 TB (best $/TB size now) JBOD drives to handle the complete backup.  With an eSATA interface card (~$20) that supports port multiplier, it would be then possible to do a complete backup of a relatively large system without the complexity and WinPE incompatibility with GPT.  However, assuming as Moore's Law portends, larger drives will eventually provide lower $/TB, this approach will eventually not be the most cost effective.  Maybe Microsoft will address the core issue by then.
    Sunday, August 21, 2011 1:00 AM
  • Ken, after thinking about this for a bit and conducting a couple of experiments, I think I remember a different intent for multiple drives.  I am probably wrong but my understanding is that configuring multiple devices for backup facilitates interleaving them.  Microsoft suggests configuring two drives but then only connecting one at a time while taking the other offsite for extra protection.

    As a experiment, I did install two x 2 TB drives with both configured for backup.  With about 3.2 TB of data on my server spread over three 2 TB volumes, when I attempted a backup, I received an error that my backup storage was not large enough.  What am I missing?

    Sunday, August 21, 2011 2:15 AM