XCP-ng 8.3 updates announcements and testing

gduperrey

Updates published: https://xcp-ng.org/blog/2025/10/23/october-2025-security-and-maintenance-update-for-xcp-ng-8-3-lts/

Thank you for the tests!

manilx

@gduperrey Updated 2 pools/2 servers @home, updated 3 pools/5 servers @ office with RPU.
All fine.

flakpyro

Updates 3 pools. All fine except for the last host on the last pool ran into a yum mirror error and failed. Manually running yum update and rebooting the host worked. Sadly i then had to move VMs back around since the RPU failed and the process of migrating VMs back did not kick off as a result.

Error was

One of the configured repositories failed (Unknown),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=<repoid> ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable <repoid>
        or
            subscription-manager repos --disable=<repoid>

     5. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true

xcp-ng-base: Check uncompressed DB failed

acebmxer

Updated AMD Ryzen pool at home and update two Intel Dell r660 and r640 pools at work. No issues to report back.

marcoi

updated my two hosts without issues.

stormi

IMPORTANT NOTICE!

After publishing the updates, we discovered a very nasty bug when using the UEFI certificates that we distribute. Long story short, they're too big, and there's only limited space (57K), and combined to a preexisting bug in varstored, this will cause the VM to stop booting after Windows or any other OS attempts to append to the DBX (revocation database).

We pulled the varstored update, but those who updated can be affected.

There are conditions for the issue:

Existing VMs are not affected, unless you propagated the new certs to them
New VMs are affected only if you never installed UEFI certs to the pool yourself (through XOA or secureboot-certs install), or cleared them using secureboot-certs clear in order to use our default certificates.

If you have the affected version of varstored (rpm -q varstored yields varstored-1.2.0-3.1.xcpng8.3) :

on every host, downgrade it with yum downgrade varstored-1.2.0-2.3.xcpng8.3. No reboot or toolstack restart required.
if you have affected UEFI VMs, that is VMs that meet the conditions above but are not broken yet, don't install updates, turn them off, and fix them by deleting their DBX database: https://docs.xcp-ng.org/guides/guest-UEFI-Secure-Boot/#remove-certificates-from-a-vm. This has to be done when the VM is off. Your OS will add its own DBX afterwards.
If you already have broken VMs (this warning reaching you too late), revert to a snapshot or backup. Other ways to fix them will require a patched varstored currently in the making.

manilx

@stormi Downgraded all hosts @home and @office. I have not done anything to running Windows Server VM's or touch anything regarding certs. So I guess I'm all good.

stormi

@flakpyro Thanks for letting us know. I suppose there was a mirror that was not ready yet, or had a transient issue, and unfortunately XOA's rolling pool update feature is not very resilient to that at the moment.

flakpyro

@stormi

I reverted the package however i initially followed the directions provided by vates in the release blog post and ran "secureboot-certs clear" then on each VM with Secure boot enabled i clicked "Copy the pools default UEFI Certificates to the VM".

After reverting the updates and running secureboot-certs install again i went back and clicked "Copy the pools default UEFI Certificates to the VM" again thinking it would put the old certs back.

It sounds like this may not be enough and i need to remove the dbx record from each of these VMs. Am i correct or was that enough to fix these VMs?

Per the docs:

varstore-rm <vm-uuid> d719b2cb-3d3a-4596-a3bc-dad00e67656f dbx

Note that the GUID may be found by using varstore-ls <vm-uuid>.

When i run the command i see

Exmaple:

varstore-ls f9166a11-3c3f-33f1-505c-542ce8e1764d
8be4df61-93ca-11d2-aa0d-00e098032b8c SecureBoot
8be4df61-93ca-11d2-aa0d-00e098032b8c DeployedMode
8be4df61-93ca-11d2-aa0d-00e098032b8c AuditMode
8be4df61-93ca-11d2-aa0d-00e098032b8c SetupMode
8be4df61-93ca-11d2-aa0d-00e098032b8c SignatureSupport
8be4df61-93ca-11d2-aa0d-00e098032b8c PK
8be4df61-93ca-11d2-aa0d-00e098032b8c KEK
d719b2cb-3d3a-4596-a3bc-dad00e67656f db
d719b2cb-3d3a-4596-a3bc-dad00e67656f dbx
605dab50-e046-4300-abb6-3dd810dd8b23 SbatLevel
fab7e9e1-39dd-4f2b-8408-e20e906cb6de HDDP
e20939be-32d4-41be-a150-897f85d49829 MemoryOverwriteRequestControl
bb983ccf-151d-40e1-a07b-4a17be168292 MemoryOverwriteRequestControlLock
9d1947eb-09bb-4780-a3cd-bea956e0e056 PPIBuffer
9d1947eb-09bb-4780-a3cd-bea956e0e056 Tcg2PhysicalPresenceFlagsLock
eb704011-1402-11d3-8e77-00a0c969723b MTC
8be4df61-93ca-11d2-aa0d-00e098032b8c Boot0000
8be4df61-93ca-11d2-aa0d-00e098032b8c Timeout
8be4df61-93ca-11d2-aa0d-00e098032b8c Lang
8be4df61-93ca-11d2-aa0d-00e098032b8c PlatformLang
8be4df61-93ca-11d2-aa0d-00e098032b8c ConIn
8be4df61-93ca-11d2-aa0d-00e098032b8c ConOut
8be4df61-93ca-11d2-aa0d-00e098032b8c ErrOut
9d1947eb-09bb-4780-a3cd-bea956e0e056 Tcg2PhysicalPresenceFlags
8be4df61-93ca-11d2-aa0d-00e098032b8c Key0000
8be4df61-93ca-11d2-aa0d-00e098032b8c Key0001
5b446ed1-e30b-4faa-871a-3654eca36080 0050569B1890
937fe521-95ae-4d1a-8929-48bcd90ad31a 0050569B1890
9fb9a8a1-2f4a-43a6-889c-d0f7b6c47ad5 ClientId
8be4df61-93ca-11d2-aa0d-00e098032b8c Boot0003
8be4df61-93ca-11d2-aa0d-00e098032b8c Boot0004
8be4df61-93ca-11d2-aa0d-00e098032b8c Boot0005
4c19049f-4137-4dd3-9c10-8b97a83ffdfa MemoryTypeInformation
8be4df61-93ca-11d2-aa0d-00e098032b8c Boot0006
8be4df61-93ca-11d2-aa0d-00e098032b8c BootOrder
8c136d32-039a-4016-8bb4-9e985e62786f SecretKey
8be4df61-93ca-11d2-aa0d-00e098032b8c Boot0001
8be4df61-93ca-11d2-aa0d-00e098032b8c Boot0002

So the command would be:

varstore-rm f9166a11-3c3f-33f1-505c-542ce8e1764d d719b2cb-3d3a-4596-a3bc-dad00e67656f dbx correct? 

Does "d719b2cb-3d3a-4596-a3bc-dad00e67656f " indicate the old certs have been re-installed?

dinhngtu

@flakpyro It's in the middle. But the "d719b2cb-3d3a-4596-a3bc-dad00e67656f dbx" part is always the same across all VMs.

After reverting the updates and running secureboot-certs install again

This will create a pool-level dbx which does not have the problem seen in varstored-1.2.0-3.1. So as long as you propagated the variables to all affected VMs without any errors, there's no need to delete them manually. But you can always delete them again if you're not sure.

flakpyro

@dinhngtu Ah okay, i was wondering if "d719b2cb-3d3a-4596-a3bc-dad00e67656f" indicated i was back on the safe certs since it is the same on all VMs since reverting and clicking "Copy the pools default UEFI Certificates to the VM"

So i need to run

varstore-rm f9166a11-3c3f-33f1-505c-542ce8e1764d d719b2cb-3d3a-4596-a3bc-dad00e67656f dbx

while powered off to be safe?

flakpyro

Awesome thanks for the response. I took a snapshot and tried rebooting a VM and it booted back up without issue simply by clicking the propagate button on each affecting VM after reverting and running "secureboot-certs install"

acebmxer

@stormi would this issue cause this behavior? VM stuck at startup...

Screenshot 2025-10-24 091455.png

Screenshot 2025-10-24 091510.png

dinhngtu

@acebmxer Looks like it. You can recover by installing a preliminary test update here:

wget https://koji.xcp-ng.org/repos/user/8/8.3/xcpng-users.repo -O /etc/yum.repos.d/xcpng-users.repo
yum update --enablerepo=xcp-ng-ndinh1 varstored varstored-tools
secureboot-certs clear

Then propagate SB certs to make sure that subsequent dbx updates will run normally.

Sorry for the inconvenience.

Greg_E

@dinhngtu

I was just getting ready to go update my pool... So is it safe now? And do these certs only affect Secure Boot VMs or UEFI VMs as well?

acebmxer

@dinhngtu Thank you for that reply.

Just to clarify I have 4 host. 2 host i updated to latest update once they became available to public via pool updates. The other 2 host I had to push the second beta release to get command secureboot-certs install to work. Then I pushed the rest of the update again once they became public.

So far im only seeing 1 vm having the issue on the later 2 host the had the beta updates installed. There that test PC and 1 windows server (Printsrver), xoproxy, and xoce.

Should i run those commands on all 4 host or just the later 2 with the troubled vm?

dinhngtu

@Greg_E said in XCP-ng 8.3 updates announcements and testing:

@dinhngtu

I was just getting ready to go update my pool... So is it safe now? And do these certs only affect Secure Boot VMs or UEFI VMs as well?

This problem will affect UEFI VMs. See the announcement above for more details.

In short, if you haven't updated, you should be safe; the offending update has been withdrawn and no longer available from yum update (as long as you're not using the testing branch).

@acebmxer said in XCP-ng 8.3 updates announcements and testing:

@dinhngtu Thank you for that reply.

Just to clarify I have 4 host. 2 host i updated to latest update once they became available to public via pool updates. The other 2 host I had to push the second beta release to get command secureboot-certs install to work. Then I pushed the rest of the update again once they became public.

So far im only seeing 1 vm having the issue on the later 2 host the had the beta updates installed. There that test PC and 1 windows server (Printsrver), xoproxy, and xoce.

Should i run those commands on all 4 host or just the later 2 with the troubled vm?

I haven't tested using different versions of varstored within the same pool.

acebmxer

@dinhngtu

All 4 host have the same version. They were just not updated the same way at the same time was the point i was making and that so far only 1 vm seems to be affected.

But i guess to play it self i should downgrade all 4 host.

Edit - ran the following commands on master host of pool with the vm with issue. VM now boots up.

Sorry for all the questions.

wget https://koji.xcp-ng.org/repos/user/8/8.3/xcpng-users.repo -O /etc/yum.repos.d/xcpng-users.repo
yum update --enablerepo=xcp-ng-ndinh1 varstored varstored-tools
secureboot-certs clear

Should run that above commands on all the remaining host?

Or should i run this command on any of the four host?

yum downgrade varstored-1.2.0-2.3.xcpng8.3

dinhngtu

@acebmxer You can confirm if there are other affected VMs using this command:

xe vm-list --minimal | xargs -d, -Ix sh -c "echo Scanning x 1>&2; varstore-ls x" > /dev/null

If there are still affected VMs, you must fix them on varstored-1.2.0-3.2 by secureboot-certs clear + propagating before downgrading to 2.3 (if you wish).

Note that downgrading to 2.3 with pool certs cleared means you'll need to set up guest Secure Boot again. So I recommend staying on 3.2 if it's possible for you.

flakpyro

@dinhngtu The output of that command seems to result in the output of "Scanningn every UUID in my pool", most of which do not use SB. Im guessing that normal and i do not have any affected VMs any longer?