[lustre-discuss] quotacheck on a live fs (pre 2.4)

[John White]

So in the lustre manual, it says:
lfs quotacheck requires the file system to be quiescent (i.e. no modifying operations like write, truncate, create or delete should run
concurrently). Failure to follow this caution may result in inaccurate user/group disk usage. Operations that do not change Lustre files (such as read or mount) are okay to run. 

With that understood, what sort of inaccuracies are introduced by a live filesystem (with writers) during a quotacheck?  We have a file system we desperately need to use the quota mechanisms to get even ballpark estimates of per-user usage.  A downtime is not really in the cards at the moment.  Further, the file system isn’t long for this world and will be blown away in a matter of months (we just need to make it that long).  

Will writers on the fs make the data absolutely useless or will it just make things… fuzzy?