having an issue with Qemu Agent on my VM using snapshot backup of cPanel

Spirogg

Well-Known Member
Feb 21, 2018
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hello,

I have Proxmox setup on my server and a VM with my cPanel with a few sites on it.. every time I try to backup the VM of AlmaLinux 8.5 and cPanel Qemu Agant Freeze and stops the back.

on Proxmox forum i read this here

Code:
Securetmp enables /dev/loop mounts

You'll need to disable it if you want to run snapshots/backups with CloudLinux

https://support.cpanel.net/hc/en-us/articles/360058525333-How-to-disable-scripts-securetmp

This is what CloudLinux sent me

Hello,

The issue is not related to CloudLinux directly, but to Qemu agent, which does not freeze the file system(s) correctly. What is actually happening:

When VM backup is invoked, Qemu agent freezes the file systems, so no single change will be made during the backup. But Qemu agent does not respect the loop* devices in freezing order (we have checked its sources), which leads to the next situation:
1) freeze loopback fs
---> send async reqs to loopback thread
2) freeze main fs
3) loopback thread wakes up and trying to write data to the main fs, which is still frozen, and this finally leads to the hung task and kernel crash.

I'm afraid we have no further recommendations at this point.

Thank you.
just wondering if I try to turn off SecureTMP


what issues may I have if any on my server?

and if I do see an Issue how can I turn it back on after following the directions to turn it off from cPanel article

thanks so much

Spiro
 
Last edited by a moderator:

cPRex

Jurassic Moderator
Staff member
Oct 19, 2014
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Root Administrator
Hey there! We don't recommend changing the tmp settings. If tmp isn't secured, it's possible for scripts to run in there and access things they shouldn't.

If you wanted to reverse the changes you'd get the same prompt when the script was run a second time - you'd just choose "y" instead of "n" to reactivate it.

Full documentation on that can be found here: