Tuesday, November 20, 2007

FakeRAID and Linux

A couple of months ago my C drive packed up. Nothing too major but a lot of hassle reinstalling the OS and all the application S/W. I didn’t want to do that again so I decided to go the RAID5 route. (Of course, this was before doing any real research).

I bought an Intel motherboard with the ICH8R chip that supports RAID5; no budget for a RAID controller card, unfortunately. Since I have been a Windows user for some time (Mac OS6/7/7.5 and X, and for a while in the 90s OS/2), I began by creating the RAID array and installing XP on one of the partitions I set up on the array. All went smoothly. The I tried installing Linux (FC7) on another partition, also in the RAID5 array, but the installer didn’t recognize the RAID5.

After some belated research, I discovered that the Intel chip delivers what is termed ‘fake raid‘ I eventually installed FC7 on a spare disk outside the array. Not really a solution as my data is on the fake RAID5 array. It appears that that the Linux dmraid module which supports raid arrays will support the ICH8R chip but only for RAID 0 and 1. Although I know nothing of the complexity of writing this kind of driver, it seems odd that Intel’s south bridge is not supported since (again an assumption) I presume a large number of motherboards use this chip. Of course it may be that this chips is far lass common among the developer community, hence the lack of a need for this support. So for the moment it’s back to good ol’ Windows XP until I can figure something out. Likely next step: a new motherboard.