I have a 12.04 system with fakeraid for the root partition across /dev/sda and /dev/sdb. I want to convert it from using dmraid to mdadm (so I can monitor it with /proc/mdstat for instance)
mdadm is 3.2.5, and it says in the manpage it can understand ddf and imsm metadata, and this indeed seems to be the case:
# mdadm --examine /dev/sda
/dev/sda:
Magic : Intel Raid ISM Cfg Sig.
Version : 1.1.00
Orig Family : 8bc6b015
Family : 8bc6b015
Generation : 00000010
Attributes : All supported
UUID : 2ff8e106:4db45609:75487070:XXXXXXXX
Checksum : b92d117e correct
MPB Sectors : 1
Disks : 2
RAID Devices : 1
Disk00 Serial : S14CNEAXXXXXXXX
State : active
Id : 00000000
Usable Size : 234435342 (111.79 GiB 120.03 GB)
[Volume0]:
UUID : a7fb0d20:01efbd85:c89e3f79:bf86cf8e
RAID Level : 1
Members : 2
Slots : [UU]
Failed disk : none
This Slot : 0
Array Size : 222715904 (106.20 GiB 114.03 GB)
Per Dev Size : 222716168 (106.20 GiB 114.03 GB)
Sector Offset : 0
Num Stripes : 869984
Chunk Size : 64 KiB
Reserved : 0
Migrate State : idle
Map State : uninitialized
Dirty State : clean
Disk01 Serial : S14CNEAXXXXXXXX
State : active
Id : 00000001
Usable Size : 234435342 (111.79 GiB 120.03 GB)
mdadm.conf has two relevant lines:
ARRAY metadata=imsm UUID=2ff8...
ARRAY /dev/md/Volume0 container=2ff8... member=0 UUID=...
However on bootup, the root filesystem came up as /dev/sdb1, so it looks like mdadm didn't auto-detect the arrays.
I also tried "md=1 raid=autodetect" on the kernel command line, to no avail (although the root filesystem came up as /dev/sda1 in that case; it may have been a coincidence)
Putting dmraid package back again, the system said it was unable to find the root device with the given UUID, and panicked. So now I have to specify root=/dev/sda1 explicitly.
I was kind-of expecting to break the system this way as I was planning to reinstall it anyway, but it would be great to know how to reinstall it so that it uses mdadm raid1 for its root but with BIOS-compatible metadata.
I have a 12.04 system with fakeraid for the root partition across /dev/sda and /dev/sdb. I want to convert it from using dmraid to mdadm (so I can monitor it with /proc/mdstat for instance)
mdadm is 3.2.5, and it says in the manpage it can understand ddf and imsm metadata, and this indeed seems to be the case:
# mdadm --examine /dev/sda 4db45609: 75487070: XXXXXXXX
/dev/sda:
Magic : Intel Raid ISM Cfg Sig.
Version : 1.1.00
Orig Family : 8bc6b015
Family : 8bc6b015
Generation : 00000010
Attributes : All supported
UUID : 2ff8e106:
Checksum : b92d117e correct
MPB Sectors : 1
Disks : 2
RAID Devices : 1
Disk00 Serial : S14CNEAXXXXXXXX
State : active
Id : 00000000
Usable Size : 234435342 (111.79 GiB 120.03 GB)
[Volume0]: 01efbd85: c89e3f79: bf86cf8e
UUID : a7fb0d20:
RAID Level : 1
Members : 2
Slots : [UU]
Failed disk : none
This Slot : 0
Array Size : 222715904 (106.20 GiB 114.03 GB)
Per Dev Size : 222716168 (106.20 GiB 114.03 GB)
Sector Offset : 0
Num Stripes : 869984
Chunk Size : 64 KiB
Reserved : 0
Migrate State : idle
Map State : uninitialized
Dirty State : clean
Disk01 Serial : S14CNEAXXXXXXXX
State : active
Id : 00000001
Usable Size : 234435342 (111.79 GiB 120.03 GB)
(Ditto for sdb)
So to try and migrate it, I did the following:
* apt-get remove dmraid # removes udev rules for dmraid mdadm/mkconf >/etc/mdadm/ mdadm.conf
* apt-get autoremove
* /usr/share/
mdadm.conf has two relevant lines:
ARRAY metadata=imsm UUID=2ff8...
ARRAY /dev/md/Volume0 container=2ff8... member=0 UUID=...
However on bootup, the root filesystem came up as /dev/sdb1, so it looks like mdadm didn't auto-detect the arrays.
I also tried "md=1 raid=autodetect" on the kernel command line, to no avail (although the root filesystem came up as /dev/sda1 in that case; it may have been a coincidence)
Putting dmraid package back again, the system said it was unable to find the root device with the given UUID, and panicked. So now I have to specify root=/dev/sda1 explicitly.
I was kind-of expecting to break the system this way as I was planning to reinstall it anyway, but it would be great to know how to reinstall it so that it uses mdadm raid1 for its root but with BIOS-compatible metadata.