Christoph> I have a machine with an LSI Megaraid Sofware RAID Christoph> fakeraid, which uses ddf format. About two weeks ago, when Christoph> I wanted to install the machine, I configured a RAID 1 Christoph> array in the BIOS config utility and then booted the Christoph> machine from PXE with an NFSROOT. mdadm and dmraid are Christoph> installed in the NFSROOT, dracut is used for initrd Christoph> generation. As dracut prefers mdadm over dmraid, mdadm was Christoph> chosen for RAID management. First off, I would strongly suggest that you turn off the FakeRAID entirely, just expose both disks to the OS and have the OS do the mirroring. FakeRAID was designed when CPUs were much slower, but RAID HW ASICs were also expensive. So you got the worst of both worlds! *grin* It's also almost entirely black magic to support these things, since the vendors don't generally share the details on the on-disk format that I'm aware of. I'm probably wrong in the details. But again, please just use the controller in JBOD (Just a Bunch of Disks) mode, and let mdadm mirror the disks for you. Christoph> But though mdadm detected the RAID (it created container Christoph> device /dev/md127 and raid device /dev/md126), it destroyed Christoph> it - that is, though I did not perform any action on the Christoph> raid disks, at the next boot, the BIOS RAID utility had Christoph> "forgotten" about the RAID configuration it had created Christoph> before. Christoph> Why are the possible reasons for that? Crappy implementation of semi-secret on-disk format? It could be that mdadm over-wrote something on the disk, or you partitioned it and then overwrote something the FakeRAID wanted kept around. In general, just don't go the fake RAID route, it's not worth the hassle. John -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
