Hi, We have one Lustre volume that is getting full and some other volumes that are totally empty. The one that is full is a little sluggish at times with the following messages appearing in syslog on the OSS - Lustre: 5809:0:(filter_io_26.c:698:filter_commitrw_write()) data1-OST0001: slow i_mutex 82s Lustre: 5809:0:(filter_io_26.c:711:filter_commitrw_write()) data1-OST0001: slow brw_start 82s Lustre: 5809:0:(filter_io_26.c:763:filter_commitrw_write()) data1-OST0001: slow direct_io 82s Lustre: 5809:0:(filter_io_26.c:776:filter_commitrw_write()) data1-OST0001: slow commitrw commit 82s But the same two OSS are also exporting the empty volume, which is very fast on any tests (like creation of a tar file, bonnie etc etc) I also tested the same thing on the nfs exported backup volume of the filled up lustre volume (exported from the same OSS server) and it doesn''t show any significant slow down. Is it normal for Lustre volumes to slow down when the volumes get full? Thanks Balagopal