CBT: the thread to centralize your feedback

rtjdamen

@florent deployed a fix last week that resolved the vdi_in_use errors, however after updating tot the latest XOA release that problem came back and is not resolved anymore. Not shure if this is a new issue or that it is having issues with the fix.

rtjdamen

@CJ seems like issue with the nbd connections then… hope this is something that can be fixed easy.

flakpyro

In relation to the issues i have been seeing about "can't create a stream from a metadata VDI, fall back to a base " after preforming a VM migration from one host to another i notice i also see the following in the SMLog.

Note: i also see this in the SMLog on the pool master after a VM migration even if i don't have snapshot delete enabled but simply have NBD + CBT Enabled. However the regular delta backup will proceed anyway and works fine in that case. (With snap delete disabled) With Snap delete i will see "can't create a stream from a metadata VDI, fall back to a base". Running the job again after this will produce no error in SMLog. Only after a VM migration between hosts will this appear.

Log snippit:

Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: opening lock file /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: acquired /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] ['/usr/sbin/cbt-util', 'get', '-n', '/var/run/sr-mount/16e4ecd2-583e-e2a0-5d3d-8e53ae9c1429/afd3edac-3659-4253-8d6e-76062399579c.cbtlog', '-c']
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   pread SUCCESS
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: released /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] Raising exception [460, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] ***** generic exception: vdi_list_changed_blocks: EXCEPTION <class 'xs_errors.SROSError'>, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/SRCommand.py", line 111, in run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     return self._run_locked(sr)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/SRCommand.py", line 161, in _run_locked
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     rv = self._run(sr, target)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/SRCommand.py", line 326, in _run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     return target.list_changed_blocks()
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/VDI.py", line 757, in list_changed_blocks
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     "Source and target VDI are unrelated")
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] ***** NFS VHD: EXCEPTION <class 'xs_errors.SROSError'>, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/SRCommand.py", line 385, in run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     ret = cmd.run(sr)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/SRCommand.py", line 111, in run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     return self._run_locked(sr)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/SRCommand.py", line 161, in _run_locked
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     rv = self._run(sr, target)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/SRCommand.py", line 326, in _run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     return target.list_changed_blocks()
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]   File "/opt/xensource/sm/VDI.py", line 757, in list_changed_blocks
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]     "Source and target VDI are unrelated")
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: closed /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: closed /var/lock/sm/16e4ecd2-583e-e2a0-5d3d-8e53ae9c1429/sr
Sep 17 21:07:40 xcpng-prd-03 SM: [1126556] FileVDI._snapshot for c56e5d87-1486-41da-86d4-92ede62de75a (type 2)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126556] ['uuidgen', '-r']
Sep 17 21:07:40 xcpng-prd-03 SM: [1126556]   pread SUCCESS

olivierlambert

I wonder if the migration is not also migrating the VDI with it, which shouldn't be the case. What are you doing exactly to migrate the VM?

flakpyro

@olivierlambert Im leaving the VM itself on the shared NFS SR. The above error was triggered by putting a host in maintenance mode via XOA to install the RC2 update via ISO yesterday. Other times its just by checking off a number of VMs in XOA and clicking the migrate button, selecting another host within the same pool and clicking Ok. Everything should be staying on the same shared SR.

Its like the hosts can't read each others metadata for some reason?

olivierlambert

Can you show me the exact UI steps you do in XO to do the migration? Then, in the task, are you seeing anything outside VM migrate?

Delgado

I saw these errors in my log today after starting a replication job on commit 530c3. I have not migrated these VMs to a new host or an SR.

Sep 18 08:17:12  xo-server[6199]: 2024-09-18T12:17:12.861Z xo:xapi:vdi INFO can't get changed block {
Sep 18 08:17:12  xo-server[6199]:   error: XapiError: SR_BACKEND_FAILURE_460(, Failed to calculate changed blocks for given VDIs.  [opterr=Source and target VDI are unrelated], )
Sep 18 08:17:12  xo-server[6199]:       at XapiError.wrap (file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/_XapiError.mjs:16:12)
Sep 18 08:17:12  xo-server[6199]:       at file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/transports/json-rpc.mjs:38:21
Sep 18 08:17:12  xo-server[6199]:       at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {
Sep 18 08:17:12  xo-server[6199]:     code: 'SR_BACKEND_FAILURE_460',
Sep 18 08:17:12  xo-server[6199]:     params: [
Sep 18 08:17:12  xo-server[6199]:       '',
Sep 18 08:17:12  xo-server[6199]:       'Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated], )
Sep 18 08:17:12  xo-server[6199]:       ''
Sep 18 08:17:12  xo-server[6199]:     ],
Sep 18 08:17:12  xo-server[6199]:     call: { method: 'VDI.list_changed_blocks', params: [Array] },
Sep 18 08:17:12  xo-server[6199]:     url: undefined,
Sep 18 08:17:12  xo-server[6199]:     task: undefined
Sep 18 08:17:12  xo-server[6199]:   },
Sep 18 08:17:12  xo-server[6199]:   ref: 'OpaqueRef:a7c534ef-d1d5-0578-a564-05b2c36de7be',
Sep 18 08:17:12  xo-server[6199]:   baseRef: 'OpaqueRef:5d4109f0-5278-64d8-233d-6cd73c8c6d6a'
Sep 18 08:17:12  xo-server[6199]: }
Sep 18 08:17:14  xo-server[6199]: 2024-09-18T12:17:14.459Z xo:xapi:vdi INFO can't get changed block {
Sep 18 08:17:14  xo-server[6199]:   error: XapiError: SR_BACKEND_FAILURE_460(, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated], )
Sep 18 08:17:14  xo-server[6199]:       at XapiError.wrap (file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/_XapiError.mjs:16:12)
Sep 18 08:17:14  xo-server[6199]:       at file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/transports/json-rpc.mjs:38:21
Sep 18 08:17:14  xo-server[6199]:       at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {
Sep 18 08:17:14  xo-server[6199]:     code: 'SR_BACKEND_FAILURE_460',
Sep 18 08:17:14  xo-server[6199]:     params: [
Sep 18 08:17:14  xo-server[6199]:       '',
Sep 18 08:17:14  xo-server[6199]:       'Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]',
Sep 18 08:17:14  xo-server[6199]:       ''
Sep 18 08:17:14  xo-server[6199]:     ],
Sep 18 08:17:14  xo-server[6199]:     call: { method: 'VDI.list_changed_blocks', params: [Array] },
Sep 18 08:17:14  xo-server[6199]:     url: undefined,
Sep 18 08:17:14  xo-server[6199]:     task: undefined
Sep 18 08:17:14  xo-server[6199]:   },

CJ

After changing NBD back to 1, I haven't seen any additional attached disks. However, the backup that originally succeeded with an attached disk has now failed. Odd that it will initially work with an attached disk but then fail with an attached disk.

Tristis Oris

i still have one VMs stuck without backup. Already restart it host and halt VM itself. SMlog have no records during 5minutes of that task.

      "result": {
        "code": "VDI_IN_USE",
        "params": [
          "OpaqueRef:1f96d4e7-5ca6-4070-b686-b34dd83e5442",
          "destroy"
        ],
        "task": {
          "uuid": "81a60e3a-c887-13f3-fedc-36eae232a6df",
          "name_label": "Async.VDI.destroy",
          "name_description": "",
          "allowed_operations": [],
          "current_operations": {},
          "created": "20240918T18:03:28Z",
          "finished": "20240918T18:03:28Z",
          "status": "failure",
          "resident_on": "OpaqueRef:223881b6-1309-40e6-9e42-5ad74a274d2d",
          "progress": 1,
          "type": "<none/>",
          "result": "",
          "error_info": [
            "VDI_IN_USE",
            "OpaqueRef:1f96d4e7-5ca6-4070-b686-b34dd83e5442",
            "destroy"
          ],
          "other_config": {},
          "subtask_of": "OpaqueRef:NULL",
          "subtasks": [],
          "backtrace": "(((process xapi)(filename ocaml/xapi/message_forwarding.ml)(line 4711))((process xapi)(filename lib/xapi-stdext-pervasives/pervasiveext.ml)(line 24))((process xapi)(filename ocaml/xapi/rbac.ml)(line 205))((process xapi)(filename ocaml/xapi/server_helpers.ml)(line 95)))"
        },
        "message": "VDI_IN_USE(OpaqueRef:1f96d4e7-5ca6-4070-b686-b34dd83e5442, destroy)",
        "name": "XapiError",
        "stack": "XapiError: VDI_IN_USE(OpaqueRef:1f96d4e7-5ca6-4070-b686-b34dd83e5442, destroy)\n    at XapiError.wrap (file:///opt/xo/xo-builds/xen-orchestra-202409111040/packages/xen-api/_XapiError.mjs:16:12)\n    at default (file:///opt/xo/xo-builds/xen-orchestra-202409111040/packages/xen-api/_getTaskResult.mjs:13:29)\n    at Xapi._addRecordToCache (file:///opt/xo/xo-builds/xen-orchestra-202409111040/packages/xen-api/index.mjs:1041:24)\n    at file:///opt/xo/xo-builds/xen-orchestra-202409111040/packages/xen-api/index.mjs:1075:14\n    at Array.forEach (<anonymous>)\n    at Xapi._processEvents (file:///opt/xo/xo-builds/xen-orchestra-202409111040/packages/xen-api/index.mjs:1065:12)\n    at Xapi._watchEvents (file:///opt/xo/xo-builds/xen-orchestra-202409111040/packages/xen-api/index.mjs:1238:14)\n    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)"
      }
    },

and often get Job canceled to protect the VDI chain errors for others. That continue since bad CBT commit.

Delgado

It looks like all of my backups have started erroring with "can't create a stream from a metadata VDI, fall back to a base" I am using 1 NDB connection and I am not commit 530c3. I have attached the logs of a delta backup and a replication.

2024-09-19T16_00_00.002Z - backup NG.json.txt
2024-09-19T04_00_00.001Z - backup NG.json.txt

I am seeing this in the journal logs.

Sep 19 12:01:39 hostname xo-server[11597]:   error: XapiError: SR_BACKEND_FAILURE_460(, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated], )
Sep 19 12:01:39 hostname xo-server[11597]:       at XapiError.wrap (file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/_XapiError.mjs:16:12)
Sep 19 12:01:39 hostname xo-server[11597]:       at file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/transports/json-rpc.mjs:38:21
Sep 19 12:01:39 hostname xo-server[11597]:       at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {
Sep 19 12:01:39 hostname xo-server[11597]:     code: 'SR_BACKEND_FAILURE_460',
Sep 19 12:01:39 hostname xo-server[11597]:     params: [
Sep 19 12:01:39 hostname xo-server[11597]:       '',
Sep 19 12:01:39 hostname xo-server[11597]:       'Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]',
Sep 19 12:01:39 hostname xo-server[11597]:       ''
Sep 19 12:01:39 hostname xo-server[11597]:     ],
Sep 19 12:01:39 hostname xo-server[11597]:     call: { method: 'VDI.list_changed_blocks', params: [Array] },
Sep 19 12:01:39 hostname xo-server[11597]:     url: undefined,
Sep 19 12:01:39 hostname xo-server[11597]:     task: undefined
Sep 19 12:01:39 hostname xo-server[11597]:   },
Sep 19 12:01:39 hostname xo-server[11597]:   ref: 'OpaqueRef:0438087b-5cbc-a458-a8a0-4eaa6ce74d19',
Sep 19 12:01:39 hostname xo-server[11597]:   baseRef: 'OpaqueRef:ae1330a2-0f95-6c16-6878-f6c05373a2f2'
Sep 19 12:01:39 hostname xo-server[11597]: }
Sep 19 12:01:43 hostname xo-server[11597]: 2024-09-19T16:01:43.015Z xo:xapi:vdi INFO  OpaqueRef:b6f65ae4-bee8-b179-a06c-2bb4956214ba has been disconnected from dom0 {
Sep 19 12:01:43 hostname xo-server[11597]:   vdiRef: 'OpaqueRef:0438087b-5cbc-a458-a8a0-4eaa6ce74d19',
Sep 19 12:01:43 hostname xo-server[11597]:   vbdRef: 'OpaqueRef:b6f65ae4-bee8-b179-a06c-2bb4956214ba'
Sep 19 12:01:43 hostname xo-server[11597]: }
Sep 19 12:02:29 hostname xo-server[11597]: 2024-09-19T16:02:29.855Z xo:xapi:vdi INFO can't get changed block {
Sep 19 12:02:29 hostname xo-server[11597]:   error: XapiError: SR_BACKEND_FAILURE_460(, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated], )
Sep 19 12:02:29 hostname xo-server[11597]:       at XapiError.wrap (file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/_XapiError.mjs:16:12)
Sep 19 12:02:29 hostname xo-server[11597]:       at file:///opt/xo/xo-builds/xen-orchestra-202409180806/packages/xen-api/transports/json-rpc.mjs:38:21
Sep 19 12:02:29 hostname xo-server[11597]:       at process.processTicksAndRejections (node:internal/process/task_queues:95:5) {
Sep 19 12:02:29 hostname xo-server[11597]:     code: 'SR_BACKEND_FAILURE_460',
Sep 19 12:02:29 hostname xo-server[11597]:     params: [
Sep 19 12:02:29 hostname xo-server[11597]:       '',
Sep 19 12:02:29 hostname xo-server[11597]:       'Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]',

rtjdamen

@Delgado this error sound like issues with the cbt that got invalid, could it be u had a host crash or storage issue? Does a retry create a working full?

Delgado

@rtjdamen I haven't had any hosts crash recently or any storage issue from what I can tell. The "type" in the log says delta but the size of the backups definitely look like full backups. They're also labelled as key when I look at the restore points for delta backups.

rtjdamen

@Delgado i believe this error message is incorrect, it should be something like "CBT invalid fall back to base", i have seen it random once in a while on a vm, and also with issues on a host or specific storage pool.

Tristis Oris

not sure is it CBT related, never seen that before. VM backup failed in 1min , as always, but task still looks like active.

CJ

@olivierlambert Any progress on the attached disks and multiple NBD connections issue?

Related, should we see any performance difference related to the number of NBD connections? I went from 4 to 1 and my backups are still taking the same amount of time.

olivierlambert

I'm not the right person to ask, I'm not tracking this in details. In our own prod, with use more concurrency with 1x NBD connection and that's the best combo I found so far.

CJ

@olivierlambert Is there a specific person we should ping or link to watch to get updates on the status?

olivierlambert

@florent is the main backup guy, but he's ultra busy. No guarantee, so the best isn't to ping anyone in particular and see if you have some feedback. If it's a priority, go directly on the pro support. But we'll do our best to answer here, however it can't be a priority vs support ticket.

Tristis Oris

as for about today commit https://github.com/vatesfr/xen-orchestra/commit/ad8cd3791b9459b06d754defa657c97b66261eb3 - migraion still failing.

0

fbeauchamp committed to vatesfr/xen-orchestra

fix(xo-server): migration of vm with cbt enabled disk (#8017)

olivierlambert

@Tristis-Oris Can you be more specific? What output do you exactly have?