Wednesday, July 07, 2010 5:33 PM
My WHS drive environment: 160gb system drive, two 750gb data drives, duplication enabled. All PPs installed.
My system is about 1 year old. I've seen a number of posts about what to do if the SYS drive fails. Some posts say that all one needs to do is replace the system drive with a new one and do a "re-install"; other posters say that when they did this they were NOT offered the re-install option, which seems to imply that all the data on the DATA disks will be lost.
So what is the recommended procedure? Should I make a backup image of the SYS partition (using Acronis) so that I can replace it on the new drive? How does one guarantee that if the SYS drive fails they will be offered the "re-install" option?
Wednesday, July 07, 2010 5:47 PMModerator
There is no supported or reliable way to back up the system drive. Drive Extender and other Windows Home Server components keep a variety of fairly volatile information on the system drive, and that information is mostly tied to other disks in the system as well. The result is that any backup of the system drive will be out of date almost immediately, and trying to restore it at a later date may result in data loss.
There are a lot of factors that might contribute to a recovery failure: the order that setup sees drives in, what drivers are needed for all of your drives to be visible to setup, etc.. The best thing for an individual system builder to do is to practice the recovery process, so they know the quirks of their own hardware. Failure to practice and (hopefully) document the process means that you will execute it for the first time under stress, and will have to figure out issues that you may never have faced before to execute it successfully. Trust me when I say: "This is a bad plan." :)
I'm not on the WHS team, I just post a lot. :)
Thursday, July 08, 2010 7:08 PM
Thanks for your reply.
I have to say that I think the lack of a reliable way to back up the system drive is a design flaw. The geeks among us would be happy to implement it, and the casual consumer will be floored, I'd think, to hear that some serious maintenance is required to a system no doubt touted as "simple" to repair.
What about ntbackup? I realize this is of no value for the duplicated folders, but could daily c: backups simplify restoring SYS? Is there a way to force WHS to rebuild the tombstones, separate from the re-install process? Are the tombstones themselves kept on the system drive, or scattered about?
Friday, July 09, 2010 12:19 AMModerator
Windows Home Server is sold primarily as part of a hardware/software package from an OEM. Those devices are "headless", so there's no reasonable way to restore from a backup. The "repair" for a failed system drive it to replace it and use the (OEM supplied) recovery media on a home computer to restore the server. It takes some time, but it's relatively simple and works well for the OEM devices. A traditional backup/restore scenario would be significantly more difficult. Users who build their own servers should (but rarely do) practice their own recovery scenarios, since they may have driver or BIOS problems, or other issues that make a successful recovery difficult.
As for the system drive, it contains A) the system partition, and B) the primary data partition. The primary data partition always contains all of the "tombstones", and may additionally contain some or all of the files behind them.
I'm not on the WHS team, I just post a lot. :)
Tuesday, December 13, 2011 3:16 AM
"There is no supported or reliable way to back up the system drive. Drive Extender and other Windows Home Server components keep a variety of fairly volatile information on the system drive..."
I understand that tombstones and other volatile files are kept on the D: partition. I understand that Microsoft has specifically warned in KB 975952 against using software RAID for a system drive because of incompatibility with tombstone files. I understand that backups of the system drive are ineffective, because tombstones are constantly being updated. But I don't think this rules out all possibility of backup.
I believe there are three possible ways to add stability to the system drive:
- I have read articles about virtualization. This adds possibility of creating snapshots using the hypervisor.
- I have read articles about hardware RAID, which does not involve dynamic disks. Mirroring all drives and then breaking all mirrors can create a backup of the system.
- I have a hypothesis that I'm willing to test, that the primary data partition (D:), which is created on the system disk that also hosts the boot sector and primary partition (C:), can be moved to another disk, allowing safe software mirroring of the system drive. I am going to post the results of this experiment as soon as it is finished.
I also believe that Ken is right, that practicing restorations is essential for the success of any recovery plan.
- Edited by Stephen Charles Thompson Tuesday, December 13, 2011 3:22 AM