*** plesae reply to [EMAIL PROTECTED] *** I have run up a 6 X 4.1Gb RAID5 box with raidtools 0.9 on a SYMBIOS 53C860 controller. Looking at the mdstat and resyncing all works fine. Moved some data onto Raid. Then I moved the box to another SMP Server running the same controller. It claimed that md0 was/had an Invalid argument. I cannot raidstart (see below) or even force a mkraid... "raidstart" /dev/md0: Invalid argument "mkraid" DESTROYING the contents of /dev/md0 in 5 seconds, Ctrl-C if unsure! handling MD device /dev/md0 analyzing super-block disk 0: /dev/sda1, 4186085kB, raid superblock at 4185984kB disk 1: /dev/sdb1, 4186085kB, raid superblock at 4185984kB disk 2: /dev/sdc1, 4186085kB, raid superblock at 4185984kB disk 3: /dev/sdd1, 4186085kB, raid superblock at 4185984kB disk 4: /dev/sde1, 4186085kB, raid superblock at 4185984kB disk 5: /dev/sdf1, 4186085kB, raid superblock at 4185984kB mkraid: aborted, see the syslog and /proc/mdstat for potential clues. "mdstat" Personalities : [4 raid5] read_ahead not set md0 : inactive md1 : inactive md2 : inactive md3 : inactive I can see the /dev/sda ... /dev/sdf and even run fdisk or mke2fs on them. When I try to mkraid it aborts! please... HELP! Keith