Public bug reported: I have a Lenovo server with a LSI controller that insists on having a RAID set to boot. So the BIOS is configured with a RAID0 stripe set, with a single disk:
$ dmraid -i -si *** Group superset .ddf1_disks --> Subset name : ddf1_4c5349202020202080861d60000000004711471100001450 size : 974608384 stride : 128 type : stripe status : ok subsets: 0 devs : 1 spares : 0 Notice that 'devs' is 1. This causes this bit of code in dm-activate to bail: case "$Raid_Type" in stripe) if [ "$Raid_Nodevs" -lt 2 ]; then if [ -n "$Degraded" ]; then log_error "Cannot bring up a RAID0 array in degraded mode, not all devices present." fi return 2 fi ;; Of course, the above is totally bogus, a 1 disk RAID0 is perfectly valid. I wonder if this should be testing 'status' instead? This is a problem because of GPT partitioning. If you don't start the RAID downstream tools will attempt to partition sda. The RAID metadata at the end of the disk collides with the GPT partition backup and it ends up destroying the RAID set and making the server unbootable. The kernel hints at this condition: [ 4.202136] GPT:Primary header thinks Alt. header is not at the end of the disk. [ 4.202137] GPT:974608383 != 976773167 [ 4.202138] GPT:Alternate GPT header not at the end of the disk. [ 4.202138] GPT:974608383 != 976773167 Which is 100% true, the GPT was written to the RAID, not the raw disk, and 974608383 sectors is at the end of the raid volume. ** Affects: dmraid (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1361842 Title: dmraid does not start on boot for single disk RAID0 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dmraid/+bug/1361842/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs