Veeam - Unable to attach/detach volume from a VM with a Backup Offering

[justinestruch]

problem

Hi all. I am experiencing an issue with ACS and Veeam. I have the global setting backup.enable.attach.detach.of.volume enabled. When attempting to attach/detach a volume to an instance that currently has backups and is assigned to a backup offering I get an error "Unable to attach volume to VM i-8-171-VM/2449395c-ee41-4c44-8240-f1243ee15403, please specify a VM that does not have any backups". I confirm that attaching and detaching volumes to instances that are not part of a backup offering works.

This should work according to this PR #6581 but I am not sure why I am getting the error even with the global setting backup.enable.attach.detach.of.volume enabled.

versions

Environment
Hypervisor: VMware ESXI 8.0.3, Build 24674464
Vcenter: 8.0.3 Build 24022515
Cloudstack: 4.20.1.0
Veeam: 12.3.2.3617

The steps to reproduce the bug

1. Create a new instance
2. Assign the instance to a backup offering
3. Start a backup and wait for it to complete
4. Create and add a new volume to the instance
5. NOTE: Attaching an existing volume will cause the same error

Here's some relevant logs from /var/log/cloudstack/management/management-server.log if these help

2025-08-22 15:18:22,018 DEBUG [o.a.c.f.j.i.AsyncJobManagerImpl] (qtp1404565079-21:[ctx-c51d6d8c, ctx-f7bc6659]) (logid:0ca85635) submit async job-1383, details: AsyncJob {"accountId":2,"cmd":"org.apache.cloudstack.api.command.admin.volume.AttachVolumeCmdByAdmin","cmdInfo":"{\"virtualmachineid\":\"2449395c-ee41-4c44-8240-f1243ee15403\",\"response\":\"json\",\"ctxUserId\":\"2\",\"sessionkey\":\"GUhq1rHYTujptXFAIfhoHYjAJBA\",\"httpmethod\":\"GET\",\"ctxStartEventId\":\"3645\",\"id\":\"4fbab46d-eae3-4246-b596-11ce15387399\",\"ctxDetails\":\"{\\\"interface com.cloud.storage.Volume\\\":\\\"4fbab46d-eae3-4246-b596-11ce15387399\\\",\\\"interface com.cloud.vm.VirtualMachine\\\":\\\"2449395c-ee41-4c44-8240-f1243ee15403\\\"}\",\"ctxAccountId\":\"2\",\"uuid\":\"4fbab46d-eae3-4246-b596-11ce15387399\",\"cmdEventType\":\"VOLUME.ATTACH\"}","cmdVersion":0,"completeMsid":null,"created":null,"id":1383,"initMsid":345049081830,"instanceId":155,"instanceType":"Volume","lastPolled":null,"lastUpdated":null,"processStatus":0,"removed":null,"result":null,"resultCode":0,"status":"IN_PROGRESS","userId":2,"uuid":"290945f4-2218-4f20-b12d-2b456635e769"} 2025-08-22 15:18:22,018 DEBUG [o.a.c.f.j.i.AsyncJobManagerImpl$5] (API-Job-Executor-7:[ctx-fe7f2061, job-1383]) (logid:290945f4) Executing AsyncJob {"accountId":2,"cmd":"org.apache.cloudstack.api.command.admin.volume.AttachVolumeCmdByAdmin","cmdInfo":"{\"virtualmachineid\":\"2449395c-ee41-4c44-8240-f1243ee15403\",\"response\":\"json\",\"ctxUserId\":\"2\",\"sessionkey\":\"GUhq1rHYTujptXFAIfhoHYjAJBA\",\"httpmethod\":\"GET\",\"ctxStartEventId\":\"3645\",\"id\":\"4fbab46d-eae3-4246-b596-11ce15387399\",\"ctxDetails\":\"{\\\"interface com.cloud.storage.Volume\\\":\\\"4fbab46d-eae3-4246-b596-11ce15387399\\\",\\\"interface com.cloud.vm.VirtualMachine\\\":\\\"2449395c-ee41-4c44-8240-f1243ee15403\\\"}\",\"ctxAccountId\":\"2\",\"uuid\":\"4fbab46d-eae3-4246-b596-11ce15387399\",\"cmdEventType\":\"VOLUME.ATTACH\"}","cmdVersion":0,"completeMsid":null,"created":null,"id":1383,"initMsid":345049081830,"instanceId":155,"instanceType":"Volume","lastPolled":null,"lastUpdated":null,"processStatus":0,"removed":null,"result":null,"resultCode":0,"status":"IN_PROGRESS","userId":2,"uuid":"290945f4-2218-4f20-b12d-2b456635e769"} 2025-08-22 15:18:22,034 DEBUG [o.a.c.f.j.i.AsyncJobManagerImpl] (API-Job-Executor-7:[ctx-fe7f2061, job-1383]) (logid:290945f4) Complete async job-1383, jobStatus: FAILED, resultCode: 431, result: org.apache.cloudstack.api.response.ExceptionResponse/null/{"uuidList":[],"errorcode":"431","errortext":"Unable to attach volume to VM i-8-171-VM/2449395c-ee41-4c44-8240-f1243ee15403, please specify a VM that does not have any backups"} 2025-08-22 15:18:22,041 DEBUG [o.a.c.f.j.i.AsyncJobManagerImpl$5] (API-Job-Executor-7:[ctx-fe7f2061, job-1383]) (logid:290945f4) Done executing org.apache.cloudstack.api.command.admin.volume.AttachVolumeCmdByAdmin for job-1383

What to do about it?

I think there is possibly a bug in the code or a version incompatibility mismatch (or possibly something wrong with my environment?). It would be nice if this was fixed if possible thanks!

[abh1sar]

Hi @justinestruch. Use case of #6581 was to allow Restore and attach backup volume action to attach a restored volume to an instance. Support to manually attach a volume was not added.

But since manual detach is allowed, attach should also be allowed to. This is already fixed in 4.21.

[justinestruch]

Hi @abh1sar thank you for this. So as I understand, I will just need to wait for 4.21 and then I can attach and detach volumes from an instance that has Veeam backups? Thanks!

[abh1sar]

Yes.

[justinestruch]

@abh1sar Thank you I will now close this down I appreciate the info.