physical proxy causes backup failure [Case #07039522]

[tinto1970]

good day, I've found a strange issue on a customer's installation: all backups was failing because of errors like

"Processing VMNAME Error: Failed to open VDDK disk [[LUN14] vmname/vmname_2.vmdk] ( is read-only mode - [true] )
Failed to create folder. Folder path: [C:\Windows\TEMP\VeeamBackup\VeeamAgent-9500\5eea325f.533am].
Logon attempt with parameters [VC/ESX: [vCenter.lan];Port: 443;Login: [veeam_backup];VMX Spec: [moref=vm-408];Snapshot mor: [snapshot-679];Transports: [san];Read Only: [true]] failed because of the following errors:
Failed to create folder. Folder path: [C:\Windows\TEMP\VeeamBackup\VeeamAgent-9500\81ecb8a1.533am]."

After some troubleshooting I rebooted the physical proxies (win 2019, writing to a datadomain via FCP) and the backups run fine for a while and, later, failed again.
I've noticed that proxy prx1 had strange behaviour again after login (no icons on desktop, start menu not working). I disabled it and backups run fine again.

I think, and the support engineer agrees, we should reinstall the prx1 proxy. I would like to know if someone had a similar issue and if he/she found a fastest way to repair it

Thanks a lot

[tinto1970]

sorry, the os of the prx1 is Windows Server 2022, no 2019.

I also think that it could be an hw issue, it's not as easy to investigate...

Update! It was very simple and I am very stupid: C: 100% full

sorry

[tinto1970]

update2: the cause is "stupid" but the resolution is not that easy.

The C: disk has been saturated by the folder C:\ProgramData\Veeam
which is 20GB big in the prx2,3,4 and more than 40GB in prx1 which is also acting as proxy for a file job.
It seems the proxy installation path is not customizable...

[tinto1970]

solution: check https://www.veeam.com/kb1825
to move the log directory away from C: