If you resized your Windows Server 2012 R2 Essentials NTFS computer backups drive, repair your client computer backup database

In Windows Disk Management, right-click, then choose:

1. Extend Volume
2. Shrink Volume

Both have been available using the Disk Management GUI  since the Windows Server 2008 R2 days. You may have to defrag first for the shrink to work, but having it built into Windows sure beats having to rely on third party tools like PartitionMagic.

Here's the thing

I didn't know that it can apparently cause problems if you do a shrink or extend on the drive letter that's holding your WS2012R2E (Windows Server 2012 R2 Essentials) client computer backup database. Witnessed it myself today, both after a shrink, then after an extend. Problems like:

• all the DEVICES show a "Backup status" of "Unknown" [pictured above]
• Backups client computers fail, sometimes warning "Errors are detected in the backup database"
• only sometimes does a scary red Critical X shows up under Health Monitoring, saying "Errors exist in a client computer backup"

Don't freak out, you'll likely just need a few mouse clicks and some patience. All actions are at your own risk, since I cannot possibly be responsible for your data loss. If possible, snapshot or backup your entire disk before you begin.

Here's the fix

Open up that WS2012R2 Dashboard, where it may or may not indicate that you need to do these steps:

To repair backup.

1. Open the Dashboard.
2. Click Devices, and then click Client computer backup tasks.
3. Click Tools, and then click Repair now.
4. Follow the instructions to complete the wizard

Finally, the parts the documentation doesn't spell out (each of which took many hours, with my 2.5TB database size, on a single 6TB WD Red drive on an Intel SATA3 port on Z68 Motherboard)

1. Wait until CPU activity from WSSBackup.exe service is complete and the errors may clear, this could take hours, and there is no progress bar! (screenshot below)
2. Eventually, WSSBackupRepair.exe may show up in Resource Monitor and in GUI form, then you'll have a progress bar (screenshot below)

In the TechNet article Manage client computer backup in Windows Server Essentials, Ctrl+F search for "To repair the backup database", and you'll see this key line

Depending on how large the backup database is, the database repair can take several hours.

Even if the repair status UI never shows up, you can use Resource Monitor, CPU, Processes, then sort on the CPU column, to keep an eye on things. Or you can go do something else, then come back from time to time, to see if it's done with elevated CPU/Disk activity. At that point, it's like that Backup status, and the backups, are normal again.

Please take a moment to drop a brief comment below, if this article helped you at all. Thank you!