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?
