[lustre-discuss] Odd quota behavior with Lustre/ZFS

[Mohr Jr, Richard Frank (Rick Mohr)]

I recently set up a Lustre 2.8 file system that uses ZFS for the backend storage (both on the MDT and OSTs).  When I was doing some testing, I noticed that the output from lfs quota seemed odd.  While the quota information for the amount of used space seemed correct, the info on the number of files was off.  For example, when I started with no files, “lfs quota” showed this:

     Filesystem  kbytes   quota   limit   grace   files   quota   limit   grace
/lustre/xxxxx
                     33       0       0       - 18446744073709551595       0       0       -

As I created empty files one-by-one, the number of files kept incrementing.  Once I had 21 files created, lfs quota then reported that I had zero files:

     Filesystem  kbytes   quota   limit   grace   files   quota   limit   grace
/lustre/xxxxx
                    211       0       0       -       0       0       0       -

Has anyone else encountered this “off by 21” problem before?  I didn’t see anything online, but perhaps I missed something.

--
Rick Mohr
Senior HPC System Administrator
National Institute for Computational Sciences
http://www.nics.tennessee.edu