On Fri, May 25, 2012 at 06:37:05AM -0400, Joe Landman wrote: > Hi folks: > > Just ran into this (see posted output at bottom). 3.2.14 kernel, > MD RAID 5, xfs file system. Not sure (precisely) where the problem > is, hence posting to both lists. > > [root@siFlash ~]# cat /proc/mdstat > Personalities : [raid1] [raid6] [raid5] [raid4] > md22 : active raid5 sdl[0] sds[7] sdx[6] sdu[5] sdk[4] sdz[3] sdw[2] sdr[1] > 1641009216 blocks super 1.2 level 5, 32k chunk, algorithm 2 > [8/8] [UUUUUUUU] > > md20 : active raid5 sdh[0] sdf[7] sdm[6] sdd[5] sdc[4] sde[3] sdi[2] sdg[1] > 1641009216 blocks super 1.2 level 5, 32k chunk, algorithm 2 > [8/8] [UUUUUUUU] > > md21 : active raid5 sdy[0] sdq[7] sdp[6] sdo[5] sdn[4] sdj[3] sdv[2] sdt[1] > 1641009216 blocks super 1.2 level 5, 32k chunk, algorithm 2 > [8/8] [UUUUUUUU] > > md0 : active raid1 sdb1[1] sda1[0] > 93775800 blocks super 1.0 [2/2] [UU] > bitmap: 1/1 pages [4KB], 65536KB chunk > > > md2* are SSD RAID5 arrays we are experimenting with. Xfs file > systems atop them: > > [root@siFlash ~]# mount | grep md2 > /dev/md20 on /data/1 type xfs (rw) > /dev/md21 on /data/2 type xfs (rw) > /dev/md22 on /data/3 type xfs (rw) > > vanilla mount options (following Dave Chinner's long standing advice) > > meta-data=/dev/md20 isize=2048 agcount=32, > agsize=12820392 blks > = sectsz=512 attr=2 > data = bsize=4096 blocks=410252304, imaxpct=5 > = sunit=8 swidth=56 blks > naming =version 2 bsize=65536 ascii-ci=0 > log =internal bsize=4096 blocks=30720, version=2 > = sectsz=512 sunit=8 blks, lazy-count=1 > realtime =none extsz=4096 blocks=0, rtextents=0 But you haven't followed my advice when it comes to using default mkfs options, have you? You're running 2k inodes and 64k directory block size, which is not exactly a common config The question is, why do you have these options configured, and are they responsible for things being slow? > All this said, deletes from this unit are taking 1-2 seconds per file ... Sounds like you might be hitting the synchronous xattr removal problem that was recently fixed (as has been mentioned already), but even so 2 IOs don't take 1-2s to do, unless the MD RAID5 barrier implementation is really that bad. If you mount -o nobarrier, what happens? CHeers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
