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Old 07-23-2008, 02:32 PM   #1
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device mapper with Intel Embedded RAID

I have a new server with an Intel Embedded RAID Technology II chipset. I also have 6 disks attached to the RAID controller. I partitioned the disks to two: 1 disk for boot, and five disk as a RAID0 for storage. I installed Fedora 9 (2.6.25-14) and it works fine. It can detect the RAID device and makes the following device mapper entries in /dev/mapper:

ddf1_4c53492020202020808626820000000035acbde800000a28 // 1th disk
ddf1_4c53492020202020808626820000000035acbde800000a28p1 // p1 on 1th disk
ddf1_4c53492020202020808626820000000035acbde800000a28p2 // p2 on 1th disk
ddf1_4c53492020202020808626820000000035acbde800001450 // 2nd disk set
ddf1_4c53492020202020808626820000000035acbde800001450p1 // p1 on 2nd set
ddf1_4c53492020202020808626820000000035acbde800001450p2 // p2 on 2nd set

The problem starts when I boot the system with my own kernel which is 2.6.25. I built and configured my kernel with the same options as installed Fedora. I also built initrd the same as Fedora one (the contents are exactly the same). But when I boot the system with my kernel the device mapper is gone and I cannot see device mapper files. As a result I cannot see the RAID disks!

Any ideas?

thanks for any help.

Last edited by rmir; 07-23-2008 at 02:44 PM.
Old 07-24-2008, 08:45 AM   #2
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I can't tell from your question if you configured the RAID in the Intel RAID chipset. Presumably you did or you wouldn't have mentioned it. I don't know the whole answer. I don't want to look up the product specs so I'm going to assume that you have a fake RAID chip set. If you boot a running system and issue the dm-raid -ay command then your RAID disks should show up in /dev/dm-? such as /dev/dm-0. They should ALSO show up under /dev/mapper. That's as far as I've gotten with fake RAID since I only learned that much in order to recover files from a fake RAID system.

Last edited by stress_junkie; 07-24-2008 at 08:46 AM.
Old 07-24-2008, 10:28 AM   #3
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Yes, I did configured the RAID from the controller. In fact, I made two RAID sets, one with one disk, the other one with 5 disks. The one disk RAID is used for boot and the rest of them is used for storage (I tried to put all of them (6) disks in the RAID, but Fedora failed to boot).

I tried using "dmraid -ay" to activate the RAIDs but it cannot detect the bigger RAID set! Also I would like to boot normally from my first disk RAID as the installed Fedora.


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