Fix ERROR_NOT_SNAPSHOT_VOLUME (0X00001AB9) on Windows

Quick Answer for Advanced Users

Run diskpart, select the volume, then run delete volume and re-create it with create volume to restore snapshot capabilities. Or use vssadmin list volumes to verify the volume is a snapshottable type.

What's Going On?

This error tripped me up the first time too. ERROR_NOT_SNAPSHOT_VOLUME with code 0X00001AB9 means Windows Volume Shadow Copy (VSS) is telling you: "Hey, this volume can't be a snapshot source or target." Usually happens when you're backing up a dynamic volume that's been split, or when a volume's snapshot metadata got corrupted. I've seen it most often on Windows Server 2016 and 2019 after an unexpected reboot during a backup job.

The real fix involves either reassigning the volume's snapshot path or rebuilding its VSS configuration. Let's walk through it.

Fix Steps

1. Open an elevated Command Prompt. Press Win+X, then choose "Command Prompt (Admin)" or "Windows PowerShell (Admin)".
2. List your volumes. Type vssadmin list volumes and press Enter. Check if the volume you're targeting shows up. If it doesn't, VSS doesn't see it — that's your problem.
3. Check the volume type. Run diskpart, then list volume. Find the volume that's failing. Look at the "Type" column. If it says "Simple" or "Mirrored" you're fine. If it says "Stripe" or "RAID-5" and you're running Windows Server, you need to make sure the VSS hardware provider supports it. Most don't.
4. Assign a snapshot path (most common fix). In diskpart, select the volume: select volume X (replace X with your volume number). Then run: volume snapshot path=I:\ (replace I with your target drive letter). This tells VSS where to store snapshot metadata. Without it, VSS won't touch the volume.
5. Rebuild VSS metadata. If step 4 didn't work, delete and re-create the volume's VSS configuration. Run: vssadmin delete shadows /for=I: /all to purge old snapshots. Then vssadmin resize shadowstorage /for=I: /on=I: /maxsize=10GB to reset the storage limit.
6. Restart the VSS service. Run net stop vss then net start vss. Then retry your backup operation.

Alternative Fixes if the Main One Fails

If you're still hitting the error after those steps, try these:

• Check drive letters. A volume without a drive letter won't be snapshottable. Go to Disk Management, right-click the volume, and assign a letter.
• Use a different backup tool. I've seen VSS fail on certain dynamic disk layouts. Try a VSS-aware backup tool like Veeam or Windows Server Backup instead of manual VSS commands.
• Convert to basic disk. If the volume is dynamic, converting it to basic disk fixes the issue permanently. But that requires wiping the volume, so back up your data first. Use diskpart and clean then convert basic.
• Update your storage drivers. Outdated or buggy drivers from Dell, HP, or Lenovo can corrupt VSS metadata. Head to your OEM's support site and grab the latest storage controller driver.

How to Prevent This From Happening Again

Once you've fixed the error, here's how to keep it from coming back:

• Don't reboot during a backup. I know it sounds obvious, but unplanned restarts are the #1 cause of VSS corruption. Add a Group Policy to prevent shutdown while backup jobs run.
• Monitor VSS health weekly. Run vssadmin list writers every Monday to catch writer failures early. If any writer shows "Failed" or "Stable", investigate before they cause snapshot errors.
• Keep your backup log. Set your backup software to log all VSS operations. When something fails, you'll have a trace instead of just a cryptic error code.