New maintenance update candidates for XCP-ng 8.3 LTS

gduperrey

We have just released security updates for xen and blktap. Full details are available on the blog: https://xcp-ng.org/blog/2026/09/08/september-2026-security-updates-1-for-xcp-ng-8-3-lts/

stormi

@mthird said:

Spoke to soon. While the updates succeeded, one of the nodes is rebooting every few minutes due to an HA self-fence.

Could you open a dedicated thread and ping me there?

gduperrey

Hello @XCP-ng-JustGreat,

I cannot comment on RPU issues via XO. I would recommend creating a new topic to report the problem directly to the XO team so they can analyze it.

As you can see, we recommend validating updates via the command line directly on XCP-ng before releasing them. That is a different scenario.

However, if several of you are experiencing RPU issues with XO, a dedicated topic will allow that team to investigate the situation and consult other teams if necessary. This would ensure the issue is better addressed and analyzed

gduperrey

Hello @acebmxer,

I can see from the support ticket and the summary that the issue appears to be resolved and was linked to the NFS update on the Synology. It’s great that you were able to find the solution.

gduperrey

@manilx If the pools are up to date, I would try restarting the XO VM to see if the task persists.

If it does persist, it might be best to open a separate topic for the XO team.

gduperrey

Thank you everyone for your tests and your feedback!

The updates are live now: https://xcp-ng.org/blog/2026/08/27/august-2026-updates-2-for-xcp-ng-8-3-lts/

gleh

New maintenance update candidates for XCP-ng 8.3 LTS

This batch of updates focuses on storage bug fixes and performance improvements.

What changed

Storage

blktap:
When CBT is enabled, an issue occurred where tapdisk opened cbtlog instead of the primary QCOW2 image. This previously caused commit operations (ENOTSUPP) and leaf-coalesce routines to fail, resulting in excessive storage consumption on the SR. Tapdisk now correctly bypasses the cbtlog image to allow proper coalescing.
sm: Fix a bug where the coalesce on a secondary host of a QCOW2 VDI on LVMSR could corrupt LVM metadata and would need manual intervention to restore them.
xapi:
- Migration speeds are now improved for sparse QCOW2-backed VDIs, as empty sectors are no longer transferred.
- Preserve VDI tags on migration. This is a foundational fix for kubernetes integration.

Versions

blktap: 3.55.5-9.3.xcpng8.3 -> 3.55.5-9.4.xcpng8.3
sm: 3.2.12-23.4.xcpng8.3 -> 3.2.12-23.5.xcpng8.3
xapi: 26.1.16-1.1.xcpng8.3 -> 26.1.16-1.2.xcpng8.3

Test on XCP-ng 8.3

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

As usual, normal use and anything else you want to test.

Test window before official release of the updates

~24 hrs

We would like to thank users who shared feedback since our last call for testing: @Andrew, @JeffBerntsen, @MajorP93, @XCP-ng-JustGreat, @acebmxer, @bufanda, @flakpyro

gduperrey

Hello @MajorP93,

Several things in your message raise questions for me.

First, this SR:

1x Linstor vSAN iSCSI configured as QCOW2

What is this storage and how is it configured?
Currently, we do not support QCOW2 on Linstor/Xostor. So, is it simply an iSCSI device to which you have applied the QCOW2 format, or is it a Xostor on the XCP-ng pool?

Regarding jumbo frames, we do not use them internally and are not currently testing them. It is often recommended not to use them for the management interface, as indicated in the XCP-ng documentation: https://docs.xcp-ng.org/networking/

Non-standard MTUs (such as jumbo frames) are not supported on management interfaces. Using them can lead to serious issues, including failed pool member joins or unexpected network outages.

Is that the case here?

Team - OS Platform Release

Posts

New maintenance update candidates for XCP-ng 8.3 LTS

What changed

Storage

Versions

Test on XCP-ng 8.3

What to test

Test window before official release of the updates

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