Fix the vzquota "Device or resource busy" error

What does this error mean?

A container is a small private server that runs inside a bigger server. OpenVZ is software that makes such containers. It uses a tool called vzquota to track how much disk space each container uses. A quota is a limit, like a cap on how much you can put in a drawer.

The message says "Quota on syscall for id: Device or resource busy". That means the quota for the container is already switched on, or something is still using the container's disk. The container cannot start until that is cleared.

This guide needs root access on the host server. Root is the all-powerful admin user. Most VPS customers cannot do this. If you only have a VPS, open a ticket with support instead.

Steps

Log in to the host server over SSH as root. SSH lets you type commands on a faraway computer.
Replace 101 in these commands with your container's ID number. Find the ID with:
```
vzlist -a
```
It lists every container and its ID.
Check that the container is really stopped:
```
vzctl status 101
```
It should say "down".
Turn off the old quota for that container:
```
vzquota off 101
```
This releases the quota that is stuck.
Try to start the container again:
```
vzctl start 101
```
If it still says "busy", look for a process still using the container's folder:
```
lsof +D /vz/private/101
```
It lists programs holding files open. Stop them, then repeat step 4.
If it still fails, check that the container is not still mounted:
```
vzctl umount 101
```

Warning: Do not delete quota files by hand unless support tells you to. Take a backup of the container first, because wrong changes can lose data.

If it keeps happening

Repeated errors can point to a full disk or a crash. Check free disk space with df -h. It shows how full each disk is. If you cannot solve it, open a ticket at https://secure.hostvento.com/submitticket.php and paste the full error.

Quick recap

The error means the container's quota is stuck on or in use.
Use vzquota off ID, then start the container again.
Look for open files with lsof if it stays busy.
Back up before making deeper changes.
Ask support if you do not have host access.