sob, 06 gru 2008, 12:51:08 +0800, Kirby Zhou napisa?(a): > I have tried. > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > volume writebehind > type performance/write-behind > option aggregate-size 8MB # default is 0bytes > option flush-behind off # default is 'off' > subvolumes unify0 > end-volume > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > [@123.25 ~]# dd if=/opt/xxx of=/mnt/xxx > 100353+0 records in > 100353+0 records out > 51380736 bytes (51 MB) copied, 129.343 seconds, 397 kB/s > > [@123.25 ~]# dd if=/opt/xxx of=/mnt/xxx bs=16M > 16+0 records in > 16+0 records out > 268435456 bytes (268 MB) copied, 23.5073 seconds, 11.4 MB/s I've got almost the same problem on 1950 dell servers connected with Gigabit Ethernet. Also untaring kernel archive lasts about 5 to 10 times more then on local disks. I've tested some configs with write behind, io-threads, io-cache - I can achieve only few percents better performance. I've also notice, that while writing small files (<=1kB) for every one send packet there is one ACK recieving from server. I have tought that with window-size option from write-behind translator I can get ACKing for more packets then one. I thing there is a problem with low performance, but that was my loosely ideas. ;) Regards. -- rash at konto pl
