Since sometime last week some back-ups have been failing with this message:
Creating backup for virtual server example.org ..
<tt>setquota: Cannot open quotafile //aquota.user: Operation not permitted
setquota: Not all specified mountpoints are using quota.
</tt> at /usr/libexec/webmin/web-lib-funcs.pl line 1433.
This is happening on at least two virtual servers, and I can't think what they might have in common. Another virtual server is not having problems.
What could have started causing this out of the blue last week?