@christopher-petzel Great news! I will test and report after it is available in a global update. Thank you Christopher.

@dinhngtu When creating GPOs if you have an non-policy setting for all users in the settings area for the agent config. The policy based registry settings can go into “Software\Policies”, for the appropriate HKEY and keys. In which case the policy based registry entries supersede the non-policy ones, when considering also the HKLM vs HKU and HKCU cascade. Also a disabling of user configuration of the managed setting(s) along with display of a message like “At least some of these settings are managed by the organisation”.

@andriy.sultanov @andriy.sultanov said: @pandusen As Teddy said above, you can't passthrough a PCI bridge, so there's no PCI devices xapi shouldn't omit here. I am not trying to pass through the bridge only the end points. The Intel arc's have 2 end points: The GPU and the Sound device. "xe pci-list" only reveals the GPU, not the sound device. (this works for nvidia and AMD) But "going the xen-cmdline way" shouldn't break anything, that's what xe pci-disable-dom0-access does behind the scenes. What issues did you see? Which steps did you follow? the sound device is available in the lspci list and can be passed through using CLI. But doing so, (using CLI for passtrough) undoes everything done using xe or the passthrough gui in XO. and results in this: https://xcp-ng.org/forum/topic/10609/xcp-ng-8.3-pci-passthrough-issue so yes, its does break something.

@poddingue Fistst of all I appreciate your answer and your position. The thing is that, even though the proxy code itself is opensource, the functionality of the plugin is basicaly behind a paywall. We are not talking about support. Actual functioning of the plugin after compiling from sources depends on license availability and there is no option to select no support or something along the lines "I built it myself from sources". Without patching the code even though the proxy is otherwise functional the backups won't work because of missing license. Hopefully the powers that can will provide an acceptable albeit community supported way to use the proxy cleanly, without touching license checks. Best regards!

Hard reboot sorted itself out

Pour l'ISO montée deux fois : My bad, j'ai ajouter un truc en trop sur mon précédent fix. Une PR est en cours pour corriger ça. Pour le problème principal : J'ai identifié la cause, mais je n'ai pas encore de solution. Sans les drivers Xen (non initialisés avant l'installation), une VM est limitée à 4 périphériques. La séquence de boot ne peut donc pas détecter le second disque contenant le fichier Kickstart (ks). Côté Packer, on semble être bloqués par cette contrainte XCP-ng. Les seules alternatives actuelles seraient de se limiter à : 2 disques + 2 CD ou 3 disques + 1 CD + HTTP (Note : L'installation manuelle fonctionne car l'installateur démarre directement, avec le driver xen_blkfront, alors qu'avec Packer, l'injection de notre fichier interrompt le flux de démarrage classique). Je vais fouiller encore un peu, mais sans certitude d'un contournement possible. (et je regarde pour ajouter le CDlabel)

On a Lenovo SR630 V4 it took Power/Performance Bias set to OS Controlled, and on an HPE DL380 Gen 11 it was the iLO Power Regulator moved off Dynamic Power Savings to OS Control Mode, with a host reboot. Both then returned real values from xenpm get-cpufreq-para instead of the failure line. @bleader is right that two vendors is not enough to document, so if your host works, could you post the vendor, the exact setting name, where it lives, and whether you needed a reboot? Dell, Supermicro and anything AMD are the obvious gaps. I don't know whether the firmware is withholding p-state control outright or just not publishing the ACPI objects Xen looks for, so I would rather collect settings than write up a mechanism I can't back. Thanks!

@irtaza9 i would look a the usual suspect, /var/log/SMlog /var/log/xensource.log see https://docs.xcp-ng.org/troubleshooting/

@neal https://github.com/vatesfr/xen-orchestra/issues/10260

@acebmxer No problem, that's excellent news, thanks for the feedback!

@djingo Hi ! Does all your VMs have guest tools ?

No problem, this is always good to have feedback and cases showing an error and the explanation

@yllar Hello, We are still validating the ISOs, but we are getting closer to releasing them. We hope to make them available soon.

I have also opened a support ticket with Veeam. Well trying to... Issue with my account preventing me to and working to fix that issue. Veeam forum did make this statment about CBT and snapshots - There is one known snapshot issue that I'm guessing could possibly have this side-effect (noted in the release notes BTW). We take standard Xen snapshots for CBT but then immediately rename them with our own naming convention. We've noticed that sometimes this rename operation returns success status even if it fails. In this case I can see how this might throw this sort of error but again best to confirm w/support Veeam support ticket - 08188639 Update from Veeam - Thanks for the update I'm currently checking with my team and I will update as soon as possible, what I noticed in the debug logs is the following API failing \Backup\Plugins\XEN\Backup\Backup Job 1\Delilah ArcDC02 with debug enable 2026-08-07 20:05:04.067 00006 DEBUG | [BackupService]: <== Request localhost:19000, IsTaskFinished, body: {"taskId":"491371d9-4699-4087-b549-9862d2188177"} 2026-08-07 20:05:04.067 00006 DEBUG | [BackupService]: ==> Response localhost:19000, IsTaskFinished, success, duration: 0.1404 msec, body: false 2026-08-07 20:05:04.843 00019 INFO | [XenRpcClient]: Start ListChangedBlocks 2026-08-07 20:05:04.843 00019 DEBUG | [XenRpcClient]: <== Request https://192.168.20.3/Async.VDI.list_changed_blocks, body: ["OpaqueRef:b77ca409-d438-d97e-d8c3-f212647ad469","OpaqueRef:8c83f698-8836-3b4c-1506-8e97315aae1f"] 2026-08-07 20:05:04.845 00019 DEBUG | [XenRpcClient]: ==> Response https://192.168.20.3/Async.VDI.list_changed_blocks code: "OK", duration: 2 msec, body:{"opaque_ref":"OpaqueRef:c9389aa3-552a-0aa4-a5bc-f9b4f7a40e98"} 2026-08-07 20:05:04.845 00019 DEBUG | [XenRpcClient]: <== Request https://192.168.20.3/task.get_record, body: ["OpaqueRef:c9389aa3-552a-0aa4-a5bc-f9b4f7a40e98"] 2026-08-07 20:05:04.847 00019 DEBUG | [XenRpcClient]: ==> Response https://192.168.20.3/task.get_record code: "OK", duration: 2 msec, body:{"uuid":"72b5eb58-5053-d77a-9ee9-089ffaed4541","name_label":"Async.VDI.list_changed_blocks","name_description":"","allowed_operations":["cancel"],"current_operations":{},"created":"2026-08-08T00:05:04Z","finished":"1970-01-01T00:00:00Z","status":"pending","resident_on":"OpaqueRef:05e44734-86d0-c9f6-5079-25633df7bf06","progress":0.0,"type":"<none/>","result":"","error_info":[],"other_config":{},"subtask_of":"OpaqueRef:NULL","subtasks":[],"backtrace":"()","opaque_ref":null} 2026-08-07 20:05:04.848 00019 DEBUG | [XenRpcClient]: Current task Async.VDI.list_changed_blocks:72b5eb58-5053-d77a-9ee9-089ffaed4541. Status: "pending" Progress: 0 2026-08-07 20:05:06.848 00018 DEBUG | [XenRpcClient]: <== Request https://192.168.20.3/task.get_record, body: ["OpaqueRef:c9389aa3-552a-0aa4-a5bc-f9b4f7a40e98"] 2026-08-07 20:05:06.850 00018 DEBUG | [XenRpcClient]: ==> Response https://192.168.20.3/task.get_record code: "OK", duration: 1 msec, body:{"uuid":"72b5eb58-5053-d77a-9ee9-089ffaed4541","name_label":"Async.VDI.list_changed_blocks","name_description":"","allowed_operations":[],"current_operations":{},"created":"2026-08-08T00:05:04Z","finished":"2026-08-08T00:05:05Z","status":"failure","resident_on":"OpaqueRef:05e44734-86d0-c9f6-5079-25633df7bf06","progress":1.0,"type":"<none/>","result":"","error_info":["SR_BACKEND_FAILURE_460","","Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]",""],"other_config":{},"subtask_of":"OpaqueRef:NULL","subtasks":[],"backtrace":"(((process xapi)(filename lib/backtrace.ml)(line 210))((process xapi)(filename ocaml/xapi/storage_utils.ml)(line 150))((process xapi)(filename ocaml/xapi/message_forwarding.ml)(line 141))((process xapi)(filename ocaml/libs/xapi-stdext/lib/xapi-stdext-pervasives/pervasiveext.ml)(line 24))((process xapi)(filename ocaml/libs/xapi-stdext/lib/xapi-stdext-pervasives/pervasiveext.ml)(line 39))((process xapi)(filename ocaml/xapi/rbac.ml)(line 228))((process xapi)(filename ocaml/xapi/rbac.ml)(line 238))((process xapi)(filename ocaml/xapi/server_helpers.ml)(line 78)))","opaque_ref":null} 2026-08-07 20:05:06.850 00018 DEBUG | [XenRpcClient]: Current task Async.VDI.list_changed_blocks:72b5eb58-5053-d77a-9ee9-089ffaed4541. Status: "failure" Progress: 1 2026-08-07 20:05:06.850 00018 DEBUG | [XenRpcClient]: <== Request https://192.168.20.3/task.destroy, body: ["OpaqueRef:c9389aa3-552a-0aa4-a5bc-f9b4f7a40e98"] 2026-08-07 20:05:06.851 00018 DEBUG | [XenRpcClient]: ==> Response https://192.168.20.3/task.destroy code: "OK", duration: 0.735 msec, body:"" 2026-08-07 20:05:06.851 00018 ERROR | [XenRpcClient]: Failed ListChangedBlocks. Error: [Task 72b5eb58-5053-d77a-9ee9-089ffaed4541 (Async.VDI.list_changed_blocks) failed: . SR_BACKEND_FAILURE_460. . Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]. Veeam.Vbf.Common.Exceptions.ExceptionWithDetail: [Task 72b5eb58-5053-d77a-9ee9-089ffaed4541 (Async.VDI.list_changed_blocks) failed: . SR_BACKEND_FAILURE_460. . Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]. ---> Failed to calculate changed blocks for given VDIs. --- End of inner exception stack trace --- at Veeam.XenBackup.RestClient.XenRpcClient.GetTaskResult(XenRef`1 taskRef, CancellationToken cancellationToken) at Veeam.XenBackup.RestClient.XenRpcClient.<>c__DisplayClass94_0.<<ListChangedBlocksAsync>b__0>d.MoveNext() --- End of stack trace from previous location --- at Veeam.Vbf.Common.Helper.Retry.RetryHelper.ExecuteActionAsync[T](Func`2 asyncAction, String description, ILogger logger, LogLevel logLevel, CancellationToken cancellationToken) 2026-08-07 20:05:06.851 00018 INFO | [XenRpcClient]: Retry after 10 sec. Retry 6/10 for ListChangedBlocks There is a XEN forum and guide from him, but I need to check internally as first https://docs.xenserver.com/en-us/xenserver/developer/changed-block-tracking-guide/troubleshoot.html#you-cant-list-changed-blocks-between-two-vdi-snapshots CBT: the thread to centralize your feedback | XCP-ng and XO forum https://xcp-ng.org/forum/topic/9268/cbt-the-thread-to-centralize-your-feedback/364 Regards Update - Veeam came back and suggested I power off the vms with the warrning and power back on. This cleared the error for 2 out of the 4 vms. 1 vm still showed the error the other vm i was not able to power off at that time. @olivierlambert - From veeam... After checking with my team, is it possible if you can engage XEN support on this, I checked some of the XEN forum including the KB article about how to troubleshoot CBT errors, seems to be a clean metadata that can be done from their side Troubleshoot Changed Block Tracking | Develop for XenServer CBT: the thread to centralize your feedback | XCP-ng and XO forum Regards Looks like our issue may be different at the end even with involving CBT... Let me know if i should continue in a new post. Support ticket created - Ticket#7762393

I put both of your questions on a spare host, because I couldn't answer either from memory. On colons: xe creates a key literally called auto_poweron:true with an empty value, so the entries you saw were three separate keys and none was the real auto_poweron, and typing false afterwards just made another one. It exits 0 and prints nothing every time, which I'd call a rough edge rather than a feature, though other-config is free-form by design so I don't know that the CLI is meant to validate keys at all. On the sleep: with rc.local executable and no sleep, it fired at 16 seconds of uptime and xe appliance-start came back with Error: Connection refused (calling connect ), exit 1, in under a tenth of a second. The VM stayed halted and nothing was reported anywhere, since rc.local has no terminal to print to. rc-local.service only orders after basic.target and network.target, nothing toolstack-related, while xapi-wait-init-complete.service took 30 seconds on that host, which is presumably why 60 was barely enough for you. There's an xapi-init-complete.target that looks like the right thing to order a unit against instead of guessing at a delay, though I haven't tried it so treat that as a lead rather than advice. The executable-bit half is in the docs now, it went onto the troubleshooting page after you reported it: https://docs.xcp-ng.org/troubleshooting/common-problems

@poddingue Here is the ouput of the command: $ xe host-list params=uuid,name-label,address uuid ( RO) : 8b0ac09d-a723-4a18-85ae-86660746d8aa name-label ( RW): frodo address ( RO): 192.168.1.13 uuid ( RO) : 2b1579d3-d45a-4d67-a423-20ddbbd61e00 name-label ( RW): meriadoc address ( RO): 192.168.1.12 uuid ( RO) : 7641f7a2-5774-4303-939f-afc3b6b4e35e name-label ( RW): samwise.somezone.net address ( RO): 192.168.1.10 With moving it to the Docker container, I only did that after I was already experiencing the same issue with a system that used the script to setup XO. I had hoped it was something on the XO side but it's seems more like it's the XCP-NG side.

I put this on a spare host rather than guess at it twice. The delay runs after the start, not before it. With start-delay=20 the VM was up in about a second and the call then sat there for the rest of the twenty before returning. So the VM you set it on is already running, and what waits is whatever was going to happen next. Ordering does exist, but it belongs to vApps: an appliance groups VMs and order decides which goes first (https://docs.xcp-ng.org/vms/vm-lifecycle#vapps). The part that surprised me is that nothing starts an appliance when the host boots. I put both test VMs in one, rebooted, and they stayed down. Autostart is a single bulk start of everything flagged for auto power on, it walks them one at a time, and it ignores order. I set order=2 on a VM and it still went first. So a delay does hold up the VMs behind it at boot, which is probably what you were seeing, but you cannot pick which one goes first. For your NAS and seedbox I do not think there is a clean answer today. There is an open request for exactly that, a VM that waits on another VM: https://github.com/vatesfr/xen-orchestra/issues/8433, and your case would be a good one to add to it. What I still cannot explain is why yours stopped starting at all. A delay stalling the ones behind it would explain a late start, not one that never comes up.

I forgot to mention: XOA Premium Current version: 6.6.2 (stable channel)

Version 4.7 build 105 works fine with applied fix (modules/path). I have made upgrade form 4.5 -> 4.7, before update I have uninstall all plugins than upgrade to 4.7. Apply fixes and install plugins.