The storage and XAPI teams are currently investigating the issues that have been reported.
There is no final solution yet, but we are getting closer. Unfortunately, there is no ETA at this time.
Thank you very much for all your testing and feedback! 
Stormi's helper.
Science-Fiction and Fantasy lover. Love books, comics, animes...
The storage and XAPI teams are currently investigating the issues that have been reported.
There is no final solution yet, but we are getting closer. Unfortunately, there is no ETA at this time.
Thank you very much for all your testing and feedback! 
The fix, which was proposed as a test to resolve some of the issues encountered, has been integrated into an official update candidate which will be released to everyone next time we publish updates. For more information on this update, you can consult the following post: https://xcp-ng.org/forum/post/96135
The kernel RPM integrating the patch is now available on the xcp-ng-testing repo. So you can already upgrade and use it. To do this, here are the commands:
yum clean metadata --enablerepo=xcp-ng-testing
yum update kernel --enablerepo=xcp-ng-testing
reboot
It will be released to all our users in an upcoming security update or update train. We don't have a date yet.
Updates published: https://xcp-ng.org/blog/2025/07/03/july-2025-security-and-maintenance-update-for-xcp-ng-8-3-lts/
Thank you for the tests!
As you may know, we group non-urgent updates together for a collective release, in order not to cause unnecessary maintenance for our users.
The moment to release such a batch has come, so here they are, ready for user tests before the final release.
XAPI:
xe host-emergency-ha-disablexe vm-migrate command may fail with the error 'Failure: Unknown tag/contents'.xsconsole:
guest-templates-json:
sm:
blktap: Synced with XS82ECU1075: Improvements on coalesce performance.curl: Backport fixes for several CVE: CVE-2024-2004, CVE-2024-2379, CVE-2024-2398, CVE-2024-2466, CVE-2024-6197, CVE-2024-7264openssl: Update to version 1.0.2k-26 from CentOS 7 updates and backports of available CVE fixes from openssl upstream. Update from CentOS 7 Includes fixes for CVE-2021-3712, CVE-2022-2078 and CVE-2023-0286. Backport are fixing CVE-2019-1547, CVE-2019-1551 and CVE-2019-1563.xs-openssl: Rebased on version 1.1.1k-12 from CentOS 8 Stream. Include fixes for CVE-2023-5678, CVE-2023-3446, CVE-2023-3817 and a proper fix for CVE-2020-25659.zstd: Update to version 1.5.5 to avoid an extremely rare cases of corruptionxcp-ng-xapi-plugins: Enhance error reporting when a command run on a host fails.xenserver-status-report: Update to latest version, synced with XS82ECU1058python-defusedxml: Added as a new dependency of xenserver-status-report.intel-i40e-alt: From version 2.22.20-3.1 to 2.22.20-5.1mellanox-mlnxen-alt: From version 5.9.0.5.5.0-1.1 to 5.9.0.5.5.0-1.2mlx4-modules-alt: To resolve some issues with CX3 cards and SR-IOV, we added an updated version 4.9-7.1.0.0-LTS of this driver.As a dependency of XOSTOR:
http-nbd-transfer:
From an up to date host:
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.
blktap: 3.37.4-4.1.xcpng8.2curl: 8.6.0-2.2.xcpng8.2forkexecd: 1.18.3-12.1.xcpng8.2gpumon: 0.18.0-20.1.xcpng8.2guest-templates-json: 1.10.7-1.2.xcpng8.2http-nbd-transfer: 1.4.0-1.xcpng8.2message-switch: 1.23.2-19.1.xcpng8.2ocaml-rrd-transport: 1.16.1-17.1.xcpng8.2ocaml-rrdd-plugin: 1.9.1-17.1.xcpng8.2ocaml-tapctl: 1.5.1-17.1.xcpng8.2ocaml-xcp-idl: 1.96.7-6.1.xcpng8.2ocaml-xen-api-client: 1.9.0-20.1.xcpng8.2ocaml-xen-api-libs-transitional: 2.25.7-1.1.xcpng8.2openssl: 1.0.2k-26.2.xcpng8.2python-defusedxml: 0.7.1-1.xcpng8.2rrd2csv: 1.2.6-17.1.xcpng8.2rrdd-plugins: 1.10.9-14.1.xcpng8.2sm: 2.30.8-13.1.xcpng8.2sm-cli: 0.23.0-63.1.xcpng8.2squeezed: 0.27.0-20.1.xcpng8.2varstored-guard: 0.6.2-17.xcpng8.2vhd-tool: 0.43.0-20.1.xcpng8.2wsproxy: 1.12.0-21.xcpng8.2xapi: 1.249.38-1.11.xcpng8.2xapi-nbd: 1.11.0-19.1.xcpng8.2xapi-storage: 11.19.0_sxm2-19.xcpng8.2xapi-storage-script: 0.34.1-18.1.xcpng8.2xcp-networkd: 0.56.2-17.xcpng8.2xcp-rrdd: 1.33.4-6.1.xcpng8.2xenopsd: 0.150.19-5.1.xcpng8.2xenserver-status-report: 1.3.16-3.xcpng8.2xcp-ng-xapi-plugins: 1.10.1-1.xcpng8.2xs-opam-repo: 6.35.13-4.xcpng8.2xs-openssl: 1.1.1k-12.3.xcpng8.2xsconsole: 10.1.13.1-2.1.xcpng8.2zstd: 1.5.5-1.el7Optional packages:
kernel-alt: 4.19.265-2.xcpng8.2intel-i40e-alt: 2.22.20-5.1.xcpng8.2mellanox-mlnxen-alt: 5.9_0.5.5.0-1.2.xcpng8.2New optional package:
mlx4-modules-alt: 4.9_7.1.0.0-1.xcpng8.2Normal use and anything else you want to test. The closer to your actual use of XCP-ng, the better.
~1 week.
The update is published. Thanks for your tests!
Blog post: https://xcp-ng.org/blog/2022/11/04/november-2022-security-update/
A new update for the Xen packages is ready, which brings a significant improvement in live migration performance on AMD systems under heavy load, that we add to the previous batch of updates for a common publication.
xen: Improve migration performance on AMD systems under heavy load.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.
xen: 4.17.6-4.1.xcpng8.3Normal use and anything else you want to test. If you have a pool with AMD processors, we're interested in your feedback regarding live migration under heavy load.
~4/5 days
Hello,
We've added a card to our backlog to investigate this topic.
Update published: https://xcp-ng.org/blog/2025/01/23/january-2025-maintenance-update-for-xcp-ng-8-3/
Thank you for the tests!
A new batch of non-urgent updates is ready for user tests before a future collective release. Below are the details about these.
amd-microcode: Update AMD microcode to the 2024-11-21 drop
grub: Backport VLAN networking support for UEFI PXE boot.iperf3: Upgrade to version 3.9-13 from CentOS 7
kernel: Backport of a fix to correct cooling fan rotation speed on some Lenovo servers. For more information, you can read this thread on the forum.kexec-tools: Backport of a patch removing kernel_version(). Fixing a bug for kernel with a patchlevel greater than 255.netdata: Fixed an issue that could occur when quickly uninstalling the package, right after an unfinished installation, and leave a service in an undetermined status.slang: Fixed display and input issues in optional package mc.sm: Contains a fix for leaf coalesce where the size of the leaf to coalesce was wrongly computed before deciding if it was a live coalesce or not, it resulted in some leaf having too much data to coalesce not successing the live coalesce and staying in this state indefinitely.xapi:
xo-lite: Update to version 0.6.0. For more details, you can consult the blog post on the latest release of Xen Orchestra.Optional packages:
kernel-alt: Backport of a fix to correct cooling fan rotation speed on some Lenovo servers. For more information, you can read this thread on the forum.socat: Update the package to version 1.7.4.1 which includes a fix for a buffer overflow and security fixes.traceroute: Updated to version 2.1.5.broadcom-bnxt-en-alt: From version 1.10.2_227.0.130.0 to 1.10.3_231.0.162.0intel-i40e-alt: From version 2.22.20-3.1 to 2.26.8From an up-to-date host:
yum clean metadata --enablerepo=xcp-ng-testing
yum update --enablerepo=xcp-ng-testing
reboot
The usual update rules apply: pool coordinator first, etc.
amd-microcode: 20240503-1.1.xcpng8.3grub: 2.06-4.0.2.1.xcpng8.3iperf3: 3.9-13.xcpng8.3kernel: 4.19.19-8.0.37.1.xcpng8.3kexec-tools: 2.0.15-20.1.xcpng8.3netdata: 1.44.3-1.2.xcpng8.3slang: 2.3.2-11.xcpng8.3sm: 3.2.3-1.13.xcpng8.3xapi: 24.19.2-1.9.xcpng8.3xo-lite: 0.6.0-1.xcpng8.3Optional packages:
kernel-alt: 4.19.322+1-1.xcpng8.3socat: 1.7.4.1-6.xcpng8.3traceroute: 2.1.5-2.xcpng8.3broadcom-bnxt-en-alt: 1.10.3_231.0.162.0-1.xcpng8.3intel-i40e-alt: 2.26.8-1.xcpng8.3Normal use and anything else you want to test. The closer to your actual use of XCP-ng, the better.
None defined, but early feedback is always better than late feedback, which is in turn better than no feedback 
Thank you everyone for your tests and your feedback!
This includes updates that you have tested, as well as security updates that were under embargo.
Check out the blog post for the full list of fixes and any post-update steps: https://xcp-ng.org/blog/2026/11/10/november-2026-security-updates-3-for-xcp-ng-8-3-lts/
If you installed the kernel from our last call for testing, please read on. You can check with rpm -q kernel.
The released kernel is not the 4.19.19-8.0.49.3 you tested, but 4.19.19-8.0.46.16. Its release number is lower, so a regular update will leave your hosts on 4.19.19-8.0.49.3. We identified some issues in 4.19.19-8.0.49.3.
To downgrade and install kernel-4.19.19-8.0.46.16, run the following commands:
yum clean metadata
yum downgrade --setopt=protected_packages= kernel-4.19.19-8.0.46.16.xcpng8.3
yum update
reboot
The usual update rules apply: pool coordinator first, etc.
We expect to release a new kernel in a few days, and it will install as a normal update from either version.
If we could have waited, we would have. However, the xen security update released yesterday, given its critical nature, did not allow for that.
Please rest assured that we are aware of this issue and are doing our utmost to keep the number of releases to a minimum. We are also discussing how to communicate regarding the most critical updates and how to limit the need for reboots.
We discussed your feedback yesterday, but we don't have an explanation at the moment. Our Windows expert tried to reproduce the behavior but was unable to trigger this error.
Furthermore, we haven't encountered any issues on our end with the RPU (Rolling Pool Update) operations performed during our tests, whether done manually or via XO. It is possible, however, that we are missing the specific scenario (VMs or configuration) required to trigger this one.
Have you been able to find any further information in the host logs?
If not, could you export and send us a status report using xen-bugtool? Perhaps one of our developers will be able to spot something in it that helps explain the issue.
Conclusion:
Network layout config problems, buffer overflows, or silent packet drops are 100% ruled out here (all hardware discards are flat zero).This wasn't a user mistake or an accidental configuration mismatch. The new
smorblktapcomponents hit a deep kernel lockup handling the multi-stream VHD storage exports. The file locks deadlocked the kernel handles so badly that the hosts ignored standard and low-level CLI commands entirely, forcing a hard out-of-band physical power cycle of the XCP-ng hosts and the TrueNAS storage server just to clear the uninterruptible I/O sleep queue.I haven't touched a thing since getting the hardware back up and verifying what choked. The system is sitting exactly as it is right now. Let me know what specific debugging paths you want me to look at or what logs you need from that window to trace this down.
@storage could someone please take a look and help analyze this issue?
The storage and XAPI teams are currently investigating the issues that have been reported.
There is no final solution yet, but we are getting closer. Unfortunately, there is no ETA at this time.
Thank you very much for all your testing and feedback! 
We have just released security updates for xen and blktap. Full details are available on the blog: https://xcp-ng.org/blog/2026/10/13/october-2026-security-updates-2-for-xcp-ng-8-3-lts/
Hello,
We have received your request and thank you for the feedback on this matter.
A task card has been created and assigned to one of our teams. It has not yet been assigned to a specific developer, but we will be sure to get back to you once it has been addressed and resolved.
Thank you everyone for your tests and your feedback!
The updates are live now: https://xcp-ng.org/blog/2026/10/05/october-2026-updates-1-for-xcp-ng-8-3-lts/
We decided not to release the xen update that was initially included in the testing phase of this update cycle. It introduced changes related to support for Windows VMs with more than 64 vCPUs; a feature that is not yet fully supported and requires further work to be completely implemented.
We therefore chose to postpone it to avoid any regressions or user confusion, aiming to release a properly finalized and documented version in the near future.
This version should have no impact on your test environments, and they can continue to operate as is. Any future xen update should have a higher version number and should install over the current one.
However, if you do not wish to keep this update on your test environments, you can downgrade using the command yum downgrade xen-*.
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/
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 