Windows Server Backup keeps failing

Just in case anyone else finds this, here is your answer

Usually it is your EFI partition that cannot create the vhdx file,

the issue stems from the small size of the original EFI partition.

The easiest way to resolve this is to move your recovery partition to the end of the drive.

Then use that open space to expand your EFI partition,

you will need a 3rd party tool, or you will have to recreate the EFI partition.

New minimum partition sizes are as follows EFI 260 MB, Recovery 1.26 GB.

To move the recovery partition to the end of the disk.

First backup BCD

Then make room on the end of the disk to about 1.26 GB = 1260 MB

Create the new recovery partition and format NTFS but DO NOT give it a drive letter

(it will never go away if you do, must re-create)

Admin\CMD run reagentc /disable

Admin\CMD diskpart

list volume = identify the volume # for the New Partition

Usually #4, will be listed as a Primary partition

select volume # = where # found from above

UEFI set id=de94bba4-06d1-4d40-a16a-bfd50179d6ac

UEFI gpt attributes=0x8000000000000001

exit

reagentc /enable

reagentc /info to confirm recovery is on

If you need to resize the EFI partition you can use MiniTool, just make sure it is a tested version

Then to need to reconfigure your backup or it will fail, if this is a server

Hello Green, I am Henry and I want to help you with your issue.

The two error codes you provided are the key.

• 0x807800C5 (Failure in preparing the backup image): This means Windows Server Backup asked the Volume Shadow Copy Service (VSS) to create a point-in-time snapshot of your drive(s), and VSS failed to do so.
• 0x8004245f (The semaphore timeout period has expired): This is the reason VSS failed. A specific component that VSS was waiting for (a VSS "writer") did not respond in time, causing the entire operation to time out.

Please perform the following steps in order.

Step 1: Identify the Failing VSS Writer. This command will tell us precisely which service or application is causing the timeout.

• Run the command Command Prompt as Administrator on the server: vssadmin list writers
• Examine the output for any writer that does not show State: [1] Stable and Last error: No error.
• If you find a writer in a "Failed" or other error state, you have found the cause. Note the "Writer name" and restart the corresponding service.

Step 2: Check for a Corrupted Backup Catalog. Sometimes the existing backup set is corrupted, preventing new backups from being written.

• Navigate to your backup destination (the local drive or network share).
• Locate the folder named WindowsImageBackup.
• Rename it to WindowsImageBackup.old.
• Try running the backup again. If it succeeds, the old backup set was the problem.

Step 3: Check Hypervisor Integration Services. Since this is a VM, the VSS process is coordinated by the hypervisor's tools.

• On Hyper-V: Ensure Integration Services are up to date. You can also try reinstalling them from the Hyper-V console.
• On VMware: Ensure the latest version of VMware Tools is installed and running. A common fix is to use the "Programs and Features" control panel inside the VM to "Repair" or "Reinstall" VMware Tools.

Step 4: Let's ensure there is no underlying OS file or disk corruption.

• In your elevated Command Prompt, run sfc /scannow.
• After it completes, run DISM /Online /Cleanup-Image /RestoreHealth.
• While you have run chkdsk before, it is worth running it on the small, hidden System Reserved / Recovery partitions if they exist. You can assign them a temporary drive letter in Disk Management to do this.Please perform the following steps in order.

Hope one of these works for you.