I recall reading a while back something about disabling the filestreams allocator, or at least changing its behavior, but I'm unable to find that. What I'm trying to do is use parallel dd w/O_DIRECT to write 44 files in parallel to 44 directories, thus all 44 AGs, in one test, then write 44 files to one dir, one AG, in another test. The purpose of this quick/dirty exercise is to demonstrate throughput differences due to full platter seeking in the former case and localized seeking in the latter case. But of course the problem I'm running into in the single directory case is that the filestreams allocator starts writing all of the 44 files into the appropriate AG, but then begins allocating extents for each file in other AGs. This is of course defeating the purpose of the tests. > /mnt/VOL1/43# for i in `seq 0 43`;do xfs_bmap -v test-$i;done > test-0: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL FLAGS > 0: [0..1535]: 92341791520..92341793055 43 (160..1695) 1536 01111 > 1: [1536..3071]: 92341794688..92341796223 43 (3328..4863) 1536 00011 ... > 88: [135168..136703]: 9972480..9974015 0 (9972480..9974015) 1536 00011 > 89: [136704..138239]: 9984768..9986303 0 (9984768..9986303) 1536 00011 ... > 146: [224256..225791]: 2158167552..2158169087 1 (10684032..10685567) 1536 > 147: [225792..227327]: 2158181376..2158182911 1 (10697856..10699391) 1536 ... > 160: [245760..254975]: 10744866688..10744875903 5 (7449088..7458303) 9216 00011 > 161: [254976..256511]: 10744877440..10744878975 5 (7459840..7461375) 1536 00011 ... ... > test-43: > EXT: FILE-OFFSET BLOCK-RANGE AG AG-OFFSET TOTAL FLAGS > 0: [0..1535]: 92341936000..92341937535 43 (144640..146175) 1536 00011 > 1: [1536..3071]: 92342003584..92342005119 43 (212224..213759) 1536 00011 ... > 69: [105984..107519]: 4303912064..4303913599 2 (8945024..8946559) 1536 00011 > 70: [107520..109055]: 4303922816..4303924351 2 (8955776..8957311) 1536 00011 ... ... > 180: [276480..278015]: 8598943744..8598945279 4 (9009664..9011199) 1536 00011 ... > 181: [278016..279551]: 10744961920..10744963455 5 (7544320..7545855) 1536 00011 > 182: [279552..281087]: 10744968064..10744969599 5 (7550464..7551999) 1536 00011 ... ... Files being created are 1.6 GB. Filesystem is 44 TB. AGs are 1 TB. AGs are 0-43. Directories, /mnt/VOL1/0 - /mnt/VOL1/43. Device is a single RAID5 LUN. How can I disable or change the filestreams behavior so all files go into the one AG for the single directory test? Thanks, Stan _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
