dd

Pete Randall	Mar 10, 2003 18:21:41 GMT  7 pts dd defaults to a 512 byte block size. Specifying bs=1024k or even bs=2048k will speed things tremendously. Do not us ibs or obs, just bs. Pete
Jeff Schussele	Mar 10, 2003 18:23:42 GMT  7 pts Hi Brian, When using raw disks, block size should always be a multiple of the disk's sector size - 512 bytes. Not positive what the block size max is - it's 512 bytes default - but I've seen 64K used before, I believe. dd would probably give you an error if you exceed max. HTH, Jeff
Dietmar Konermann	Mar 10, 2003 18:37:47 GMT  7 pts I would expect the best performance if you use the maximum request size, which is, as far as I know, 1MB for the scsi layer (bs=1024k). For LVM it is 256KB, since the requests are split on logical track group boundries. Best regards... Dietmar.
eran maor	Mar 10, 2003 18:48:47 GMT  7 pts Hi well it dep. a lot of your system , if you have storng system with fast io you can you bs=4096k but it is recommend that you will use bs=2048k dont forget to put the k in the block size : dd if=/dev/zero of=/dev/rdsk/cXtXdX bs=2048k

-- map{ map{tr|10|# |;print} split//,sprintf"%.8b\n",$_} unpack'C*',unpack'u*',"5`#8<3'X`'#8^-@`<-CPP`#8V/C8`"