Anup Shukla wrote: > Format and run the dd command again. > The speed is 130MB/s now. It can vary a quite a bit depending on where you hit the disk. Remember, what you are testing is just how fast dd can read from /dev/zero and write to the file in a filesystem with 1k blocks. How that will map to real performance is another matter. > Its a bit confusing. > Does LVM slow down things? Or i did something that is not really of any > relevance to check IO speed. LVM adds very little overhead. The file and placement on disk can have more to do with raw I/O bandwidth than anything else in this particular scenario. > I used mkfs.ext3 -m0 -E stride=96 -O dir_index /dev/sdb1 ... > I have a RAID5 volume consisting of 6 disk with stripe size = 64k > I hope the stride=96 is optimal. Depends what you want... With 4k blocks in ext3 (default) a stride of 16 (16 times 4 is 64) would read one stripe from a disk. With 6 disk 16 times 6 is 96, so for every I/O you will hit each disk once and read one stripe. Ditto for writes. In general that is a good start. > Should i stick with LVM, or go back to the older way? I would never really consider not using LVM. The flexibility it adds for disk management is essential for managing your disks. //Morten