Does the output from the following commands seem odd to people? [root@nucoda root]# hdparm -t /dev/md0 /dev/md0: Timing buffered disk reads: 774 MB in 3.01 seconds = 257.52 MB/sec [root@nucoda root]# mount /dev/md0 /array [root@nucoda root]# hdparm -t /dev/md0 /dev/md0: Timing buffered disk reads: 416 MB in 3.00 seconds = 138.55 MB/sec [root@nucoda root]# umount /array [root@nucoda root]# hdparm -t /dev/md0 /dev/md0: Timing buffered disk reads: 776 MB in 3.01 seconds = 257.42 MB/sec [root@nucoda root]# Tha array is made of 10 scsi disks - each of which will read at around 60 MB/sec and all seems fine with the raid device until the fs is mounted and it appears to halve the trasnfer rate! There is no activity in the filesystem. At the moment this is with FC2, though I have tried with FC3 and numerous kernels. Tweaking around with block sizes and thing does change the speed of the raw /dev/md0 - but the speed always drops when I mount the filesystem. Can anybody explain this behaviour? Maybe I am missing something obvious, but this is baffling me - and what is worse is that it all worked until I upgraded the system. I have tried to go back, even put a new system disk in and started from scratch, but cannot get a decent read speed from the array. Chris
