Potential bug with Windows VM backup: "Body Timeout Error"

MajorP93

I can imagine that a fix could be to send "keepalive" packets in addition to the XCP-ng export-VM-data-stream so that the timeout on XO side does not occur

MajorP93

I worked around this issue by changing my full backup job to "delta backup" and enabling "force full backup" in the schedule options.

Delta backup seems more reliable as of now.

Looking forward to a fix as Zstd compression is an appealing feature of the full backup method.

andriy.sultanov

I've got a fix for this issue in the pipeline and would really appreciate if anyone here could test to confirm if it resolves the problem for you.

You'd need to install a custom build (not production-ready, be careful, all the usual warnings apply here) according to these steps:

Before updating, preferably check that exporting a particular VM with compression on results in the timeout error consistently.
Write the following file to /etc/yum.repos.d/xvatest.repo:

[xva-test-repo]
name=xva-test-repo
baseurl=https://koji.xcp-ng.org/repos/user/8/8.3/asultanov1/x86_64/
enabled=0
metadata_expire=1m
gpgcheck=1
repo_gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-xcpng

Make sure you're up to date on the rest of your packages with yum upgrade --enablerepo=testing (reboot if necessary)
Install the fix (this should install *.xvafix.1 packages):

yum upgrade xapi-core qcow-stream-tool vhd-tool --enablerepo=xva-test-repo

Restart the toolstack:

xe-toolstack-restart

MajorP93

@andriy.sultanov Thank you very much for working on this!
I can test your proposed fix in our lab during next week.
Best regards

MajorP93

@andriy.sultanov I created a small test setup in our lab. I created a WIndows VM with a lot of free disk space (2 virtual disks, 2.5 TB free space in total). Hopefully that way I will be able to replicate the issue with full backup timeout for VMs with a lot of free space that occurred in our production environment.
The backup job is currently running. I will report back once it failed and once I had a chance to test if your fix solves the issue.

MajorP93

@andriy.sultanov said in Potential bug with Windows VM backup: "Body Timeout Error":

xe-toolstack-restart

Okay I was able to replicate the issue.
This is the setup that I used and that resulted in the "body timeout error" previously discussed in this thread:

OS: Windows Server 2019 Datacenter

The versions of the packages in question that were used in order to replicate the issue (XCP-ng 8.3, fully upgraded):

[11:58 dat-xcpng-test01 ~]# rpm -q xapi-core
xapi-core-25.27.0-2.2.xcpng8.3.x86_64
[11:59 dat-xcpng-test01 ~]# rpm -q qcow-stream-tool
qcow-stream-tool-25.27.0-2.2.xcpng8.3.x86_64
[11:59 dat-xcpng-test01 ~]# rpm -q vhd-tool
vhd-tool-25.27.0-2.2.xcpng8.3.x86_64

Result:

Backup log:

{
  "data": {
    "mode": "full",
    "reportWhen": "failure"
  },
  "id": "1764585634255",
  "jobId": "b19ed05e-a34f-4fab-b267-1723a7195f4e",
  "jobName": "Full-Backup-Test",
  "message": "backup",
  "scheduleId": "579d937a-cf57-47b2-8cde-4e8325422b15",
  "start": 1764585634255,
  "status": "failure",
  "infos": [
    {
      "data": {
        "vms": [
          "36c492a8-e321-ef2b-94dc-a14e5757d711"
        ]
      },
      "message": "vms"
    }
  ],
  "tasks": [
    {
      "data": {
        "type": "VM",
        "id": "36c492a8-e321-ef2b-94dc-a14e5757d711",
        "name_label": "Win2019_EN_DC_TEST"
      },
      "id": "1764585635692",
      "message": "backup VM",
      "start": 1764585635692,
      "status": "failure",
      "tasks": [
        {
          "id": "1764585635919",
          "message": "snapshot",
          "start": 1764585635919,
          "status": "success",
          "end": 1764585644161,
          "result": "0f548c1f-ce5c-56e3-0259-9c59b7851a17"
        },
        {
          "data": {
            "id": "f1bc8d14-10dd-4440-bb1d-409b91f3b550",
            "type": "remote",
            "isFull": true
          },
          "id": "1764585644192",
          "message": "export",
          "start": 1764585644192,
          "status": "failure",
          "tasks": [
            {
              "id": "1764585644201",
              "message": "transfer",
              "start": 1764585644201,
              "status": "failure",
              "end": 1764586308921,
              "result": {
                "name": "BodyTimeoutError",
                "code": "UND_ERR_BODY_TIMEOUT",
                "message": "Body Timeout Error",
                "stack": "BodyTimeoutError: Body Timeout Error\n    at FastTimer.onParserTimeout [as _onTimeout] (/opt/xo/xo-builds/xen-orchestra-202511080402/node_modules/undici/lib/dispatcher/client-h1.js:646:28)\n    at Timeout.onTick [as _onTimeout] (/opt/xo/xo-builds/xen-orchestra-202511080402/node_modules/undici/lib/util/timers.js:162:13)\n    at listOnTimeout (node:internal/timers:588:17)\n    at process.processTimers (node:internal/timers:523:7)"
              }
            }
          ],
          "end": 1764586308922,
          "result": {
            "name": "BodyTimeoutError",
            "code": "UND_ERR_BODY_TIMEOUT",
            "message": "Body Timeout Error",
            "stack": "BodyTimeoutError: Body Timeout Error\n    at FastTimer.onParserTimeout [as _onTimeout] (/opt/xo/xo-builds/xen-orchestra-202511080402/node_modules/undici/lib/dispatcher/client-h1.js:646:28)\n    at Timeout.onTick [as _onTimeout] (/opt/xo/xo-builds/xen-orchestra-202511080402/node_modules/undici/lib/util/timers.js:162:13)\n    at listOnTimeout (node:internal/timers:588:17)\n    at process.processTimers (node:internal/timers:523:7)"
          }
        },
        {
          "id": "1764586443440",
          "message": "clean-vm",
          "start": 1764586443440,
          "status": "success",
          "end": 1764586443459,
          "result": {
            "merge": false
          }
        },
        {
          "id": "1764586443624",
          "message": "snapshot",
          "start": 1764586443624,
          "status": "success",
          "end": 1764586451966,
          "result": "c3e9736e-d6eb-3669-c7b8-f603333a83bf"
        },
        {
          "data": {
            "id": "f1bc8d14-10dd-4440-bb1d-409b91f3b550",
            "type": "remote",
            "isFull": true
          },
          "id": "1764586452003",
          "message": "export",
          "start": 1764586452003,
          "status": "success",
          "tasks": [
            {
              "id": "1764586452008",
              "message": "transfer",
              "start": 1764586452008,
              "status": "success",
              "end": 1764586686887,
              "result": {
                "size": 10464489322
              }
            }
          ],
          "end": 1764586686900
        },
        {
          "id": "1764586690122",
          "message": "clean-vm",
          "start": 1764586690122,
          "status": "success",
          "end": 1764586690140,
          "result": {
            "merge": false
          }
        }
      ],
      "warnings": [
        {
          "data": {
            "attempt": 1,
            "error": "Body Timeout Error"
          },
          "message": "Retry the VM backup due to an error"
        }
      ],
      "end": 1764586690142
    }
  ],
  "end": 1764586690143
}

I then enabled your test repository and installed the packages that you mentioned:

[12:01 dat-xcpng-test01 ~]# rpm -q xapi-core
xapi-core-25.27.0-2.3.0.xvafix.1.xcpng8.3.x86_64
[12:08 dat-xcpng-test01 ~]# rpm -q vhd-tool
vhd-tool-25.27.0-2.3.0.xvafix.1.xcpng8.3.x86_64
[12:08 dat-xcpng-test01 ~]# rpm -q qcow-stream-tool
qcow-stream-tool-25.27.0-2.3.0.xvafix.1.xcpng8.3.x86_64

I restarted tool-stack and re-ran the backup job.
Unfortunately it did not solve the issue and made the backup behave very strangely:

The backup job ran only a few seconds and reported that it was "successful". But only 10.83KiB were transferred. There are 18GB used space on this VM. So the data unfortunately was not transferred by the backup job.

Here is the backup log:

{
  "data": {
    "mode": "full",
    "reportWhen": "failure"
  },
  "id": "1764586964999",
  "jobId": "b19ed05e-a34f-4fab-b267-1723a7195f4e",
  "jobName": "Full-Backup-Test",
  "message": "backup",
  "scheduleId": "579d937a-cf57-47b2-8cde-4e8325422b15",
  "start": 1764586964999,
  "status": "success",
  "infos": [
    {
      "data": {
        "vms": [
          "36c492a8-e321-ef2b-94dc-a14e5757d711"
        ]
      },
      "message": "vms"
    }
  ],
  "tasks": [
    {
      "data": {
        "type": "VM",
        "id": "36c492a8-e321-ef2b-94dc-a14e5757d711",
        "name_label": "Win2019_EN_DC_TEST"
      },
      "id": "1764586966983",
      "message": "backup VM",
      "start": 1764586966983,
      "status": "success",
      "tasks": [
        {
          "id": "1764586967194",
          "message": "snapshot",
          "start": 1764586967194,
          "status": "success",
          "end": 1764586975429,
          "result": "ebe5c4e2-5746-9cb3-7df6-701774a679b5"
        },
        {
          "data": {
            "id": "f1bc8d14-10dd-4440-bb1d-409b91f3b550",
            "type": "remote",
            "isFull": true
          },
          "id": "1764586975453",
          "message": "export",
          "start": 1764586975453,
          "status": "success",
          "tasks": [
            {
              "id": "1764586975473",
              "message": "transfer",
              "start": 1764586975473,
              "status": "success",
              "end": 1764586981992,
              "result": {
                "size": 11093
              }
            }
          ],
          "end": 1764586982054
        },
        {
          "id": "1764586985271",
          "message": "clean-vm",
          "start": 1764586985271,
          "status": "success",
          "end": 1764586985290,
          "result": {
            "merge": false
          }
        }
      ],
      "end": 1764586985291
    }
  ],
  "end": 1764586985292
}

If you need me to test something else or if I should provide some log file from the XCP-ng system please let me know.

Best regards

Greg_E

@MajorP93

200gb free space was enough in my production system to cause this. The only thing I didn't try was filling it up until I found the point where it started working.

MajorP93

Hey @andriy.sultanov @olivierlambert

Any news on this?
If I recall correctly some work towards fixing the "compressed full backup of VMs with lots of free space" issue has been done but a fix was not (yet) pushed to the package repositories.

Is there a new test build that I could test or similar?
I would love to be able to use full backup method again.

Thanks!

olivierlambert

Let me ask internally

olivierlambert

This is the PR: https://github.com/xapi-project/xen-api/pull/6786

It's ready/reviewed, we are waiting for upstream merge. We'll make sure to re-ask for a merge ASAP.

Stay tuned!

last-genius opened this pull request in xapi-project/xen-api

closed stream_vdi: Only process allocated clusters for VHD and QCOW on XVA export #6786

MajorP93

@olivierlambert said in Potential bug with Windows VM backup: "Body Timeout Error":

This is the PR: https://github.com/xapi-project/xen-api/pull/6786

It's ready/reviewed, we are waiting for upstream merge. We'll make sure to re-ask for a merge ASAP.

Stay tuned!

Thank you very much for the update!

MajorP93

@olivierlambert @andriy.sultanov I saw that the linked PR got merged, which is awesome! I was wondering: do you plan to release this with the next round of patches or even before that as a hotfix?
In each case: if you have a test build I am happy to try it out.

Thank you and best regards

olivierlambert

Question for @stormi