Exclude Deleted Blocks - Not Working. Veeam B&R 12.3, ESXI 6.5

[seizurebot]

I'm hoping someone can help me get my Veeam B&R back to a stable state. I have a large virtual Windows 2019 fileserver that is running as a guest under esxi 6.5. The windows VM is using a spanned dynamic disk because I wanted all ~120TB of my storage presented as one large disk that I then share out over my network. ESXI only allows ~62TB virtual disks so I assigned two such disks to this windows VM and then I configured them as one spanned volume in windows disk mgmt.

So now my issue : I temporarily stored about 16TB of temporary files on this Windows VM, left them there for 3 days and then deleted them and emptied the recycle bin before my weekly backup kicked off. My backup has been running for 48 hours and counting and it's 16TB in size with still 10% more to go. Most of my weekly backups are just under 1TB in size. I was forced to cancel this backup as I don't have the extra 16TB available in this repository.

My reading has led me to understand that spanned volumes do not work with the 'deleted blocks' or 'bitlooker' feature of Veeam B&R, see : https://helpcenter.veeam.com/docs/backu ... ml?ver=120

So my next step I believe is to delete this large incremental file from my repo, 'forget' it from the veeam DB, zero-out all free/unallocated space on my windows VM and run a veeam backup again with the hope that veeam will skip the zero'd blocks of data. I found an older post on server fault which I believe should work for my purposes. See : https://serverfault.com/questions/16507 ... ompression

Specifically I am looking to run the following in powershell. Does anyone have experience with this or similar commands? Is there something better/faster/safer I can use instead?

Function CipherFreeSpace
{
$cipherjob = @()
$Job = start-job -ScriptBlock {cipher /w:F:\ }
while ($cipherjob -notcontains "Writing 0xFF")
{
Write-host "." -nonewline
Start-Sleep 2
$cipherjob += $job | Receive-Job
}
Stop-Process -processname cipher
Start-Sleep -s 3
Remove-Item -recurse F:\EFSTMPWP
$Job | Stop-Job | Remove-Job -Force
}
CipherFreeSpace

[david.domask]

Hi seizurebot,

sdelete is the method I've seen used most frequently in the past -- I think with how VMDKs will work, it will be the best and you will have to rely on Veeam's compression/dedup engine to get the incremental size manageable again.

I've not worked with cipher before and the process looks a bit iffy based on the thread (you have to manually terminate it at some point as I get it? Seems tricky), but in theory should work. Main idea is to try to get the space reclaimed as compressible/dedupable space as Bitlooker won't work here due to the spanned disks.