@poddingue
Thank you!

@jr-m4
Thank you!

@poddingue
Thank you!

@jr-m4
What would you need to do if that were needed??

I moved over to using CBT this past weekend. It seems much, much, faster and I didnt have a single error. In the past about 20% of my nightly incremental backups had errors like "can't compute delta OpaqueRef:blah-fba0-ced3-7653-blahblah from OpaqueRef:blah-b53d-3935-1af0-blahblah, fall back to a full"

I have this option "Purge snapshot data when using CBT" set to yes.

I have both of these options set to no as I don't really fully understand the implications (other than the info bubble
"Merge backups synchronously "
"Synchronize snapshots"

With that said, are there any downsides to using CBT when doing backups?

Thanks!

@poddingue
Thank you!!!

I use an NFS device to backup XCP-NG. Is there a good way to figure out what VM is using all teh storage on an NFS backup device?

For example:

One directory is :

/blahblah/backups/vm-backups/a199a812-b2bd-f4d3-a485-44ac888ab355
and there are several files like this:

/blahblah/backups/vm-backups/a199a812-b2bd-f4d3-a485-44ac888ab355/20250715T080016Z.xva

Is there an easy way to figure what belongs to what?

Thanks!

@dinhngtu
Something called "Elpha Secure" ...none of our other antivirus shows it being bad but I wanted to ask around before I unflagged it.

Has anyone had their antivirus go crazy with this version? I am getting tons of messages saying this file has a virus:

"C:\Program Files\XCP-ng\Windows PV Drivers\xenplus\xenplus.exe"

@marcoi
Same for me.

@bogikornel
Same here.....was getting the errors a while back and then they stopped. Over the last week it now happens a lot. I found that it rarely happens on incremental backups.

I have delta based backups enabled on a windows based VM. This morning, I realized I accidentally deleted a file and went restore it.

1. While in XO Orchestra I clicked Backup > File Restore
2. I selected the drive then made my way to the subdirectory. These are a few examples:
   a. In one subdirectory there are supposed to be 16 files but in the selection window there are none.
   b. In another subdirectory there are supposed to be 7 files but in the selection window there are only two.
   c. In another subdirectory there are supposed to be 138 files but in the selection window there are none.
   d. In another subdirectory there are supposed to be 91 files but in the selection window there are three.

Any thoughts?

Thanks!

@dinhngtu
You rock - thank you!

Just wanted to clarify something.

Prior to installing xcpng-winpv-9.1.100.0-Release-x64.zip, I ran Invoke-XenClean.ps1 that came with the package.

Is is still true that, in order to install (upgrade to) xcpng-winpv-9.1.145.0-Release-x64, I have to run XenClean.exe again and then run the new installer?

Its just a lot of reboots, resetting static ip addresses etc.

@florent

I tried to upload it with the "Upload button" and got this error" [2026-02-05T15_03_26.704Z - backup NG.json](Invalid file type. Allowed types are: .png, .jpg, .bmp, .txt, .diff, .patch, .jpeg) "

2026-02-05T15_03_26.704Z - backup NG_json.txt

@olivierlambert
Hmmmmmmm....good thought and you are right. I had it set at 10 and counted and it crapped out at 10. I just changed it to 100 and it worked fine!

@olivierlambert
Oops...
Amazon S3

Pool Metadata backups to S3 will work for a few days then start having an error that says "The XML you provided was not well-formed or did not validate against our published schema".

I can set up a new backup job which works a few days then starts having the same error.

This running on Xen Orchestra (commit a0e77) complied from source.

Thoughts?

Thanks!

Mystery solved:
There are numerous hosts under one master in the pool. I ran the yum update command on the master first, then rebooted, I then ran yum update on the rest and rebooted all but one. I could not reboot the last one until this morning (Saturday).

I rebooted the last one a few minutes ago and all is well.

Because I think its interesting, I'd love someone smart to explain the process of why other hosts could not do a snapshot because a different host in the pool had not been rebooted.

@Danp
WDE