Re: RAID5 slowness (how to fix?)

David Stuart wrote:

BTW I hope
it is easy to move the raid disks to another PCI IDE Controller, do I have
to run any commands for this? Are they documented somewhere?

It depends on how the RAID is setup. If the partitions are of type 0xfd (as shown by 'fdisk -l'), which is "Linux software RAID autodetect" then it *should* be automatic.

If not, then mark *one* of the disks as failed (with 'mdadm --fail'), then remove it from the array (with 'mdadm --remove'). Power down, move one slave disk to be a master on the new IDE controller, power up, add the "new" disk to the existing array (with 'mdadm --add') and wait for the RAID to re-sync (a couple of hours at least...progress info is in /proc/mdstat). Then repeat the whole process with the next disk. Don't do both at once, unless you're prepared to lose your data. RAID-5 can tolerate losing only one disk at a time. (See the mdadm manual for complete examples of the commands.)
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