Problem with installation on a Fake RAID

[Camicia]

I am trying to install a Ubuntu 9.10 server 64bit on a machine without OS.

I bought a motherboard Foxconn P55A-S ( w w w. foxconnchannel .c o m /Product/Motherboards/detail_overview.aspx?id=en-us0000473 ) that has a Marvell 88SE6121 controller (88SE61xx series).

The motherboard has a RAID support (atl east I thought) so could guarantee me that my data are safe if one HD dies. I would like to be able to replace that HD and expect that automatically or with a simple tool, I would be able to restore the system with all the HDs integer. I would also expect an increase in performances.

I have 4 HDs by Hitachi Deskstar 500Gb each \\/. I was thinking about using 3 of them in RAID 5 and 1 of them as a spare (maybe as a backup device for now).

I set up in the BIOS "Configure SATA as" -> "RAID". then pressing Ctrl-I, I could then access to an extended BIOS during the BIOS where the Intel (R) Rapid Storage Technology pop up.

First time, I set up a RAID 5 with the first 3 disks.

During the installation of Ubuntu 9.10 Server, it said that a RAID has been recognized and if I want to use it. However in this case only the 4th HD (the spare one) is displayed.

Looking on the Internet, I realized that the Marvell 88SE6121 is a "fake" Raid (the operations are run by the CPU).

I found that Intel® Matrix Storage Manager (and I am not sure that it is completely related what I own) does support only RAID 1 and 0. So I decide to give it a shot with a RAID 1+0.

I reconfigure a RAID 0+1 and this time the installation show me that I have 2 volumes of 500GB each (instead of one of 1Tb as expected).

Trying to do something with one of the displayed drive I ended up with some partitions that I don't know how to delete. Plus the installation hung up on formatting one of this partition (showing 33% and not progressing for at least 15 min).

What do I want?
1) Deleting the partition created on the first of the 2 drives in mirroring. I am not sure how you can do that from the installation.
2) Most important: Being able to take advantage of data redundancy of a RAID 1 or (better) RAID 5. Then it is nice to have: increased performance from RAID 0/1.

How do I get it to work?

Thank you in advance,
Camicia

[coopstah13]

I've seen this problem where ubuntu installer doesn't detect the raid container from a fake raid. If you are going to install linux only, I would suggest setting up a software raid using mdadm. I believe the ubuntu installer has this option (you will have to do manual/advanced partition setup). Also, with 4 disks instead of keeping 1 spare with a raid 5, you should just make a raid 6 array.

On a side note, I personally find no need for RAID in the home. RAID isn't foolproof and especially with those fakeraids, if your motherboard itself dies, you will need to find a motherboard with that same chipset in order to recover data, it could easily become a nightmare. The safest thing to do is just take backups of your most important data to an external drive.