***SATA RAID DRIVER???? help!

[computerworkspr]

Hello

I'm wondering if anyone has gotten the SATA Raid to work on Red Hat????

I need to ensure some data integrity for the server.

THanks
Ken

[JaXXoN]

Hi,

I was using four Samsung SP1614C (4 x 160 GByte) in a software RAID5
setup for about half a year with Fedora Core 3. NV-SATA (nforce3/4) and
Software RAID5 are both supported by the FC3 installer, so i could directly
define the raid set for the root parition in the FC3 installer. The boot
partition needs to be installed on a software RAID1 partition since GRUB/LILO
don't support RAID5. Please note that the NV-RAID function in the BIOS
is not used at all in this setup - this feature only defines a raid sets in a way
so that the PC BIOS could boot from the raid set using the NV-RAID BIOS
functions, but when once the Linux has been started, the OS needs to do
software RAID anyway: NV-RAID is not a *real* hardware raid. If you
want to use NV-RAID on BIOS level and software RAID on kernel level,
then mdraid probably helps. This tool can detect certain software raid sets
(such as NV-RAID) and then the kernel know how to use it. For details, see:
http://www.nvnews.net/vbulletin/show...719#post661719
However, mdraid is not supported by the FC3 installer (don't know about
FC4 or other distros), so setting up a system activly using NV-RAID could be
tricky.

Concerning data integrity in general, software RAID is basically not the most
trustfull solution, because if the system crashes or there is a power outage during
a write operation, the raid set may get inconsisten. Modern journaling file systems
*should* be able to handle that, but only if you run a resync immediatly
after the crash/power-failure from a rescue system before mounting the
filesystem again (which is pretty annoying).

Since i'm doing a lot of kernel level experimentation, my system crashes
regularily but i have never experienced problems with the software RAID
setup (although i never did a resync before mount). Nevertheless, i recently
added a real hardware raid controller (Areca ARC-1210) with battery backup
module. Alternativly to the BBM, someone can use a UPS to ensure data
integrity after power-failure.

regards

Bernhard

[JaXXoN]

Originally Posted by JaXXoN

mdraid

Ooops, it's actually "dmraid".

regards

Bernhard