Posted by: Anonymous Coward
on December 14, 2006 02:17 AM
Or a RAID-1/5/0 system, much like the 4-SATA-disk RAID-1/6/0 system I have here. RAID-1 for<nobr> <wbr></nobr>/boot since GRUB and the like understand it, RAID-5 or 6 for the main system, redundancy plus striping can be pretty sweet, and RAID-0 for stuff like<nobr> <wbr></nobr>/tmp and your local package manager cache that's either temporary or easily redownloadable and thus not in need of redundancy.
There's a very high chance (well over 90%) that it's "firmware RAID", that is, RAID that has some configuration stored in the firmware but is otherwise software based. While Linux will often work with these using usually a stub-driver based on DM-RAID, it's generally far better to run full md-kernel-software RAID, with the drives configured as standard SATA drives. Among other things, if the system dies or when it comes time for upgrade, one can simply hookup the existing drives to the new SATA controller and either load the new driver modules from the distribution kernel or recompile a new kernel with an updated custom config if that's what you've done. No incompatible RAID hardware formatted drives, since they are simply standard SATA drives combined by the kernel-RAID.
Speed for md/kernel RAID is generally about the same as with the "firmware" RAID (not uncommonly better, and very commonly less buggy, as the general kernel RAID has FAR wider testing) as well, since it's really software running the firmware RAID. The exception is true dedicated hardware RAID, but that tends to be quite expensive, such that those products are nearly without exception addon, seldom if ever implemented on-mainboard. When the feature adds another hundred bucks to the price, it just doesn't make a lot of sense to include it on the mainboard.
Learn about Linux
Download Linux
Get Linux help
Re:Onboard RAID
Posted by: Anonymous Coward on December 14, 2006 02:17 AMThere's a very high chance (well over 90%) that it's "firmware RAID", that is, RAID that has some configuration stored in the firmware but is otherwise software based. While Linux will often work with these using usually a stub-driver based on DM-RAID, it's generally far better to run full md-kernel-software RAID, with the drives configured as standard SATA drives. Among other things, if the system dies or when it comes time for upgrade, one can simply hookup the existing drives to the new SATA controller and either load the new driver modules from the distribution kernel or recompile a new kernel with an updated custom config if that's what you've done. No incompatible RAID hardware formatted drives, since they are simply standard SATA drives combined by the kernel-RAID.
Speed for md/kernel RAID is generally about the same as with the "firmware" RAID (not uncommonly better, and very commonly less buggy, as the general kernel RAID has FAR wider testing) as well, since it's really software running the firmware RAID. The exception is true dedicated hardware RAID, but that tends to be quite expensive, such that those products are nearly without exception addon, seldom if ever implemented on-mainboard. When the feature adds another hundred bucks to the price, it just doesn't make a lot of sense to include it on the mainboard.
Duncan
#