virtnbdbackup stuck in fsfreeze on Cloudlinux Pro. OS

[shahidnoorai]

Version used
1.9.14

Describe the bug
Virtnbdbackup stuck when trying to execute fsfreeze on a VM with CloudLinux Pro OS.

Expected behavior
A clear and concise description of what you expected to happen.

Hypervisor information:

• OS: Almalinux 8.7
• HV type: kvm

Logfiles:
[2023-01-29 17:49:44] INFO root virtnbdbackup - main [MainThread]: Backup level: [copy]
[2023-01-29 17:49:44] INFO root virtnbdbackup - main [MainThread]: Compression enabled, level [2]
[2023-01-29 17:49:44] INFO root virtnbdbackup - main [MainThread]: Libvirt library version: [8000000]
[2023-01-29 17:49:44] INFO virt client - getDomainDisks [MainThread]: Skipping attached [cdrom] device: [hdc].
[2023-01-29 17:49:44] INFO root virtnbdbackup - main [MainThread]: Backup will save [2] attached disks.
[2023-01-29 17:49:44] INFO root virtnbdbackup - main [MainThread]: Concurrent backup processes: [2]
[2023-01-29 17:49:44] INFO virt client - redefineCheckpoints [MainThread]: Loading checkpoint list from: [/mnt/backup/compute01.local/i-6-140-VM/checkpoints]
[2023-01-29 17:49:44] INFO root virtnbdbackup - handleCheckpoints [MainThread]: Checkpoint handling.
[2023-01-29 17:49:44] INFO root virtnbdbackup - main [MainThread]: Local NDB Endpoint socket: [/var/tmp/virtnbdbackup.2632427]
[2023-01-29 17:49:44] INFO root virtnbdbackup - main [MainThread]: Temporary scratch file target directory: [/var/tmp]
[2023-01-29 17:49:44] INFO root virtnbdbackup - startBackupJob [MainThread]: Starting backup job.

Workaround:
N/A

[abbbi]

hi,

there has been a past issue on this, the reason for the fsfreeze to stuck was an mysql/mariadb database within the
virtual machine which was not able to be set into consistent mode by the qemu agent. The issue is most probably
some service within your virtual machine causing the trouble. you should be able to reproduce it by using
virsh or direct qemu commands...

[abbbi]

Heres the issue where another user faced the same situation:

#59
#59 (comment)

Theres nothing in virtnbdbackup i can change to fix the issue. You could use the -F option to freeze only specific
filesystem mounts to track down what filesystem is causing the issue.

[shahidnoorai]

Hi,
Thank you for your reply. After reading the provided threads, I found that the problem is unrelated to CloudLinux or MySQL/MariaDB. According to https://gitlab.com/qemu-project/qemu/-/issues/520, cPanel and securetmp caused this issue. I followed the instructions on the link above and could successfully get a VM backup.
Thank you again for your great script and support. You can close this thread.