XCP-ng 8.3 updates announcements and testing

marcoi

for the latest updates. the test pool didnt move the vms when i went to reboot. so i moved them manually. rebooted master, move vms back patched and reboot 2nd test server in the pool.
Skipped trying rolling reboot in prod and followed the same process. both pools went well without other issues.

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

bufanda

@gleh installed on my lab pool. Haven’t seen any issues so far.

acebmxer

@gleh

Installed...

Updated:
  blktap.x86_64 0:3.55.5-9.4.xcpng8.3                forkexecd.x86_64 0:26.1.16-1.2.xcpng8.3                
  message-switch.x86_64 0:26.1.16-1.2.xcpng8.3       qcow-stream-tool.x86_64 0:26.1.16-1.2.xcpng8.3         
  rrdd-plugins.x86_64 0:26.1.16-1.2.xcpng8.3         sm.x86_64 0:3.2.12-23.5.xcpng8.3                       
  sm-cli.x86_64 0:26.1.16-1.2.xcpng8.3               sm-fairlock.x86_64 0:3.2.12-23.5.xcpng8.3              
  squeezed.x86_64 0:26.1.16-1.2.xcpng8.3             varstored-guard.x86_64 0:26.1.16-1.2.xcpng8.3          
  vhd-tool.x86_64 0:26.1.16-1.2.xcpng8.3             wsproxy.x86_64 0:26.1.16-1.2.xcpng8.3                  
  xapi-core.x86_64 0:26.1.16-1.2.xcpng8.3            xapi-nbd.x86_64 0:26.1.16-1.2.xcpng8.3                 
  xapi-rrd2csv.x86_64 0:26.1.16-1.2.xcpng8.3         xapi-storage-script.x86_64 0:26.1.16-1.2.xcpng8.3      
  xapi-tests.x86_64 0:26.1.16-1.2.xcpng8.3           xapi-xe.x86_64 0:26.1.16-1.2.xcpng8.3                  
  xcp-networkd.x86_64 0:26.1.16-1.2.xcpng8.3         xcp-rrdd.x86_64 0:26.1.16-1.2.xcpng8.3                 
  xenopsd.x86_64 0:26.1.16-1.2.xcpng8.3              xenopsd-cli.x86_64 0:26.1.16-1.2.xcpng8.3              
  xenopsd-xc.x86_64 0:26.1.16-1.2.xcpng8.3

MajorP93

@gleh Installed those RC packages in my test environment.
Tested basic operation. Looks good so far.
(Booted, all 3 SR connected, VMs able to start, both VHD and QCOW2)
Best regards

flakpyro

Installed on my usual hosts without issues. I am only making limited use of QCOW2 however.

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/

Andrew

@gduperrey Installed and running. Rolling pool update worked.

mthird

First time rolling update worked for my pool. Woot!

mthird

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