owl-dev - disk quotas lost on unclean shutdown

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120127233134.GA10446@openwall.com>
Date: Sat, 28 Jan 2012 03:31:34 +0400
From: Solar Designer <solar@...nwall.com>
To: owl-dev@...ts.openwall.com
Subject: disk quotas lost on unclean shutdown

Dmitry, all -

Here's a problem: after a system that uses both OpenVZ per-container
disk quotas and the regular per-user disk quotas inside containers is
shutdown uncleanly (e.g., on a power outage), the per-user quotas set or
changed during its previous uptime and per-user disk usage info changes
are lost.

We have this cron job (suggested by Dmitry) that I had hoped would be
helping against this problem:

# Update /var/vzquota/quota.* files, which is desirable such that the
# containers' recorded disk usage is closer to the actual one and, even more
# importantly, such that any per-user and per-group quotas are recorded (not
# only usage, but also the quotas themselves).  Without a cron job like this,
# if the server crashes, then not only the recorded usage will be way off, but
# also any manually set per-user and per-group quotas inside the containers
# will be lost.
2,7,12,17,22,27,32,37,42,47,52,57 * * * * root /usr/sbin/vzlist -H -o veid | xargs -r -n1 /usr/sbin/vzquota stat > /dev/null

However, in practice it only helps preserve the per-container quotas and
disk usage info, but not per-user inside containers.

Any recipe for preserving the latter as well?

At least, it looks like we'll need to edit the comment text above such
that it won't claim that this cron job achieves more than it actually does.

Thanks,

Alexander

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.