I moved all of my openvz containers from one filesystem to another (to get them on LVM). When trying to start the containers, I had the following problem:
$ sudo vzctl start 1040 Starting VE ... vzquota : (error) Quota on syscall for 1040: No such file or directory vzquota on failed [3]
I was able to fix this by deleting (I renamed it for safety) the quota file and causing openvz to reinitialize the quota.
sudo mv /var/lib/vzquota/quota.1040 /var/lib/vzquota/quota.1040.old
It took quite some time to initialize the quota (like doing du on the whole directory), but it worked after that.