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This is very strange, but I can run the Ububtu Server 12.04 64bit from the live CD to permanently install it on the HD, but when I reboot it reverts back to whatever OS was on the HD prior to the installation. The partitioning does not change, noe are there any traces of Ubuntu on the HD.

The install runs fine, prompts for a reboot, I remove the Live CD and let it reboot and it reboots into the original OS. I've tried installing and deleting and modifying partitions and said yes to making the changes permanent.

The computer is a Dell 1950 with a SAS 6 RAID controller. I've successfully installed both windows 2003 server and Fedora on it. But when I install Ubuntu after installing these, whatever OS was installed just prior to the install is what remains on the HD.

I'm not doing a dual boot. I've run the Ubuntu Boot Repair utility but that doesn't help- there is simply no trace of the ubuntu installation.

Ther is only one HD (actually 2 but in a RAID and appear as one) nor flash drive, nor any other place it could have installed other that the primary HD that the computer boots from.

Thanks for any help!!

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I suspect the problem is the raid setup, but you haven't told us what type of raid you are using (BIOS fake raid, software etc). Try searching for specific raid problems eg… – fabricator4 Jan 17 '13 at 18:51

It is probably a fakeraid, and you bypassed the raid and installed ubuntu to a single drive, which gets overwritten with the mirrored copy when you reboot.

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It's a SAS 6IR RAID card with 2 HD configured as RAID 1. Only one drive shows up during the install. When the computer boots, only the single RAID array virtual drive shows. If I remove the array config, both drives show. There appears to be differing opinions as to whether the SAS is true hardware or fake. – Davey Jan 17 '13 at 20:17
Also, when it asks about partitioning, the drive identified is "DELL VIRTUAL DISK" . There's an option in the SAS bios to enable boot for BIOS and/or OS which was set to BOTH, so I've changed that to BIOS ans re-trying the install now. – Davey Jan 17 '13 at 21:16
@Davey, does the drive show up as /dev/mapper/something or /dev/sda ( and no /dev/sdb or /dev/mapper/something )? – psusi Jan 18 '13 at 3:02

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