I never understood why redhat included the alpha quality dm-raid 
drivers. I call this alpha, since basic functionality like rebuilding a 
raidset (!) still is missing. DM-raid is a kludge to be able to do 
dual-boot with a windows system using these raid drivers.
Never, ever use dm-raid on a server. Use mdadm instead. It performs just 
as well (dm-raid is also softwaid after all) and it is stable.
If you only need mirroring, you can also use LVM to create a mirror. (I 
never used that myself, YMMV)

Another advantage of mdadm is that it is hardware  independent. Your 
raidsets will keep on working even when transferred to a different brand 
of sata controller.

By the way: if you try to install an mdadm based raid system on a drive 
that previously has been part of an intel/promise/highpoint raid set, it 
will probably fail after the first reboot.  This is because the dm-raid 
system is not active during the anaconda run, but is activated before 
mdadm in the regular startup. DM-raid will detect the old raid signature 
and lock the disk, preventing mdadm from using is. Apart from a complete 
disk wipe, you can set the 'nodmraid' kernel parameter in grub to 
prevent this from happening. Destroying the old raid-set using the bios 
tool before installing mdadm often will not work in my experience.

Roelof

Timmy wrote:
> I have installed SL 5.1 many times!  The file system can be corrupted 
> easily!  I don't know whether it is RedHat Linux's weakness.  Here are 
> my experiences:
> Case 1.
> The system might stop here at boot time:
> RedHat Nash 5.1.19.......
>
> After rebooting, it might boot normally or the system went corrupted 
> and no more boot again!
>
>
> Case 2.
> I installed 2 SATA harddisks as mirror pair on a SiI SATA software 
> RAID card.  Installation is successful but after several days' 
> operation, the system could not read the RAID pair.  Formatting was 
> needed.
>
>
> Case 3.
> After several days' downloading of a movie file through Ktorrent, the 
> file system went corrupted again!  Formatting harddisk required.
>
> I heard that downloading BT file hurts hard disk very much.  However, 
> Case 1 and Case 2 do not have any relationship with BT task.
>
> Any technique or trick to avoid this?