On Thu, Mar 19, 2015 at 06:01:50PM +0100, Hans-Peter Jansen wrote: > ~# LANG=C xfs_info /dev/sdc1 > meta-data=/dev/sdc1 isize=256 agcount=17, agsize=183105406 > blks > = sectsz=512 attr=2, projid32bit=0 > = crc=0 finobt=0 > data = bsize=4096 blocks=2929687287, imaxpct=5 > = sunit=0 swidth=0 blks > naming =version 2 bsize=4096 ascii-ci=0 ftype=0 > log =Intern bsize=4096 blocks=32768, version=2 > = sectsz=512 sunit=0 blks, lazy-count=1 > realtime =none extsz=4096 blocks=0, rtextents=0 .... > ~# LANG=C dd if=Django_Unchained.mp4 of=/dev/null bs=1M > 1305+1 records in > 1305+1 records out > 1369162196 bytes (1.4 GB) copied, 3.32714 s, 412 MB/s > > Write performance is disastrous: it's about 1.5 MB/s. > > ~# LANG=C dd if=Django_Unchained.mp4 of=xxx bs=1M > 482+0 records in > 482+0 records out > 505413632 bytes (505 MB) copied, 368.816 s, 1.4 MB/s Why did it stop half way through? ENOSPC? > 1083+0 records in > 1083+0 records out > 1135607808 bytes (1.1 GB) copied, 840.072 s, 1.4 MB/s That's incomplete, too. > The question is, what could explain these numbers. Bad alignment? Bad stripe > size? And what can I do to resolve this - without loosing all my data.. More than likely you've fragmented free space, and so writes are small random write IO. Output of 'df -h' and: $ xfs_db -r -c "freesp -s" <dev> would be instructive. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
