I have a server Xeon 3065, 4GB RAM, 2x1TB HDDs in raid0. This box is used mainly for bittorrent shared among 4 users. For that reason i formatted the home directory (where the bittorrent files are kept and served from) with xfs filesystem, because after tests it performed better than ext3. I enabled quotas on the xfs partition in order to control the diskspace used by each user.
The problem is (and this problem existed with ext3 too), that when i request a quota report with:
xfs_quota -xc 'report' /home
when the server is under moderate load (not high) or when the HDDs are under write load (a user is downloading) the report takes a lot of time (even minutes) to be generated and during that time, the load of the server doubles or triples because of the quota report requested. I switched to xfs because i thought that it would report back quotas faster, since it has native support for them and updates them realtime when something is written on the filesystem.
This is a major performance hit for me, since i would like to have a cron job to get the report every 5-10 minutes so that i can take actions when the user runs out of space.
Is there a better or faster way to get quota reports from the filesystem, even if they are not 100% accurate ?