XCP-ng 8.3 updates announcements and testing

[stormi]

@acebmxer with qcow2, the way we scan the SR regularly uses more I/O, so this may explain it.

[acebmxer]

@stormi said:

@acebmxer with qcow2, the way we scan the SR regularly uses more I/O, so this may explain it.

Thanks for the update, that this is expected. I think it its a bit a excessive being its only 4 -5 vms.

[bufanda]

@stormi said:

@bufanda I'm being told it's expected to have it the first time after the update, but in theory the next ones should be not be fulls. Can you try?

Just checked and the VM I was testing with was part of two backups and it seems that when one runs and the second starts that it will fall back. I removed the VM now from one backup and with being only member of one backup job it looks good then. Will keep an eye on it.

[stormi]

@acebmxer Can you evaluate the amount of data transferred at each spike? So that we can evaluate if it's more than expected. What's the total size of the VM disks?

[acebmxer]

@stormi

Left side of chart is all VMS running. 1.5gb/s each vm's vdi ranges from 128gb - 256gb allocated. Actual disk spaced used not sure)

The 200mb/s - 300mb/s on far right is just XO-CE running idle.

So if each vm is consuming 300mb/s ish times 4 -5 vms would get close to the 1.5gb/s.

[stormi]

Thanks. Ping @Team-Storage

[acebmxer]

@stormi said:

Thanks. Ping @Team-Storage

I think these screenshot better show the picture. It shows more or seems more dramatic on truenas.
That is two cloud inti vms 1 ubuntu and 1 alma, And 1 existing vm running on the qcow2 enabled SR.

Both SR are on the same truenas just different data sets.

[ravenet]

One thing I noticed was manually copying a qcow2 disk to an sr, with a properly generated UUID, would lock up the sr from scanning disks and updating its inventory db.
Running VMs seemed fine.

Deleting that manually copied disk from sr released the lock.

Rodney

[stormi]

We just published most of the updates tested above, plus embargoed security fixes:

https://xcp-ng.org/blog/2026/04/28/april-2026-security-and-maintenance-updates-for-xcp-ng-8-3-lts/

The release of the QCOW2 image format feature (packages sm, sm-fairlock and blktap) is planned in the coming days. You can still update a system which has these test packages with the security updates published today.

Thanks everyone for the tests!

[manilx]

@stormi Updated 2 pools @office but on both RPU failed after updating master and emptying secondary host. Had to install patches manually and then move VM's back......

[acebmxer]

@stormi

Well I just ran rolling pool update on my 2 host home lab. I wanted to watch to make sure there were no issues. Of coarse I got distracted. Only to come back and find both host updated and running. Will continue to monitor.

[flakpyro]

Updates deployed, no issues so far.

[stormi]

@manilx said:

@stormi Updated 2 pools @office but on both RPU failed after updating master and emptying secondary host. Had to install patches manually and then move VM's back......

Have you kept the logs?

[manilx]

@stormi Did not check logs but if you tell me what to look for I can.
In config-logs on XOA there is nothing relevant.

[MajorP93]

I updated both my test and production XCP-ng environments.

No issues during updates on all 6 hosts.

[manilx]

@MajorP93 Pls note that the updates had no issues. Just the RPU did not complete. 2 different things.....

[MajorP93]

@manilx It's absolutely clear to me that the method of installing updates and the changes provided by the updated packages are 2 different things.
I was not commenting on your message but rather sharing my own experience with this round of patches as this thread is generally related to XCP-ng patches.

[manilx]

@MajorP93 As you replied to my message and not to stormi.... Just wanted to clear up any misunderstanding.

[MajorP93]

@manilx No I did not. I replied to this thread in general not to your post. When looking at the answers to your specific post where you reported the RPU issue I can only see 1 reply which was written by Stormi (asking for logs).

Going forward: you can identify replies to your posts by either looking at posts that quoted your message or tagged your username using the @ character.

[stormi]

Yes, new update candidates, again!

This is, in theory, the very last round of fixes before QCOW2 support comes as an official update!

What changed

Storage

• sm + blktap:
  • Fix a never ending coalesce task and an associated tapdisk crash which would leave the QCOW2 VDI corrupted. Thanks @emerson for reporting the issue!
  • Attempting to migrate a QCOW2 towards a SR that supports QCOW2 but prefers VHD will now automatically create a QCOW2 disk at the destination if the disk is bigger than 2 TiB. Previously, it was documented as a known issue that it would attempt to create a VHD and fail.
  • Another known issue fixed: attempting to resize a QCOW2 VDI with a snapshot on a LVM-based SR no longer fails.
• xapi:
  • prevent long migrations for failing due to expiring XAPI session.
  • More security fixes related to XSA-489.

Versions:

• blktap: 3.55.5-6.6.xcpng8.3 -> 3.55.5-6.7.xcpng8.3
• sm: 3.2.12-17.6.xcpng8.3 -> 3.2.12-17.7.xcpng8.3
• xapi: 26.1.3-1.9.xcpng8.3 -> 26.1.3-1.10.xcpng8.3

Test on XCP-ng 8.3

If you are using XOSTOR, please refer to our documentation for the update method.

yum clean metadata --enablerepo=xcp-ng-testing,xcp-ng-candidates
yum update --enablerepo=xcp-ng-testing,xcp-ng-candidates
reboot

The usual update rules apply: pool coordinator first, etc.

What to test

Anything related to storage, be it with VHD or QCOW2 disks.

Test window before official release of the updates

~3 days