Hi there. I am new to this list, however didn't find this effect nor a solution to my problem in the archives or with google: short story: ------------ A single raid1 as /dev/md0 containing a reiserfs (with important data) assembled during boot works just fine: $ cat /proc/mdstat Personalities : [linear] [raid0] [raid1] md0 : active raid1 hdg1[1] hde1[0] 293049600 blocks [2/2] [UU] The same raid1 moved to another machine as a fourth raid can be assembled manually as /dev/md3 (to work around naming conflicts), but it cannot be mounted anymore: $ mdadm --assemble /dev/md3 --update=super-minor -m0 /dev/hde /dev/hdg does not complain. /dev/md3 is created. But $ mount /dev/md3 /raidmd3 gives: Jan 24 20:24:10 rio kernel: md: md3 stopped. Jan 24 20:24:10 rio kernel: md: bind<hdg> Jan 24 20:24:10 rio kernel: md: bind<hde> Jan 24 20:24:10 rio kernel: raid1: raid set md3 active with 2 out of 2 mirrors Jan 24 20:24:12 rio kernel: ReiserFS: md3: warning: sh-2021: reiserfs_fill_super: can not find reiserfs on md3 Adding -t reiserfs doesn't work either. So, the renaming or reassembling doesn't work, even if /dev/md3 is present and mdadm --detail /dev/md3 tells that everything is fine?! long story: ----------- There are two machines: an old server and a new server. Servers are in production environment, so there are no risky things to do. It's all kernel 2.6.23.12 (will try 2.6.23.14 tomorrow) and mdadm - v2.6.4 - 19th October 2007 Distribution is CRUX (everything vanilla, similar to LFS) Old server was has it's root on /dev/hda and data on /dev/md0 which is an Promise PDC20269 dual ATA raid1 configuration consisting of /dev/hde and /dev/hdg. Everything is reiserfs and working fine. This machine should be migrated over to a new server with: With VIA dual SATA raid1 configuration, three partitions for the system, swap and data. /dev/sd[ab][123] became: /dev/md[012] md0 is / md1 is swap md2 is data. everything is ext3! So I plugged the old PDC20269 with the harddisks to the new machine. During boot, md complains about a duplicate md0: Jan 24 20:21:44 rio kernel: md: Autodetecting RAID arrays. Jan 24 20:21:44 rio kernel: md: autorun ... Jan 24 20:21:44 rio kernel: md: considering sdb3 ... Jan 24 20:21:44 rio kernel: md: adding sdb3 ... Jan 24 20:21:44 rio kernel: md: sdb2 has different UUID to sdb3 Jan 24 20:21:44 rio kernel: md: sdb1 has different UUID to sdb3 Jan 24 20:21:45 rio kernel: md: adding sda3 ... Jan 24 20:21:45 rio kernel: md: sda2 has different UUID to sdb3 Jan 24 20:21:45 rio kernel: md: sda1 has different UUID to sdb3 Jan 24 20:21:45 rio kernel: md: hdg1 has different UUID to sdb3 Jan 24 20:21:45 rio kernel: md: hde1 has different UUID to sdb3 Jan 24 20:21:45 rio kernel: md: created md2 Jan 24 20:21:45 rio kernel: md: bind<sda3> Jan 24 20:21:45 rio kernel: md: bind<sdb3> Jan 24 20:21:45 rio kernel: md: running: <sdb3><sda3> Jan 24 20:21:46 rio kernel: raid1: raid set md2 active with 2 out of 2 mirrors Jan 24 20:21:46 rio kernel: md: considering sdb2 ... Jan 24 20:21:46 rio kernel: md: adding sdb2 ... Jan 24 20:21:46 rio kernel: md: sdb1 has different UUID to sdb2 Jan 24 20:21:46 rio kernel: md: adding sda2 ... Jan 24 20:21:46 rio kernel: md: sda1 has different UUID to sdb2 Jan 24 20:21:46 rio kernel: md: hdg1 has different UUID to sdb2 Jan 24 20:21:46 rio kernel: md: hde1 has different UUID to sdb2 Jan 24 20:21:46 rio kernel: md: created md1 Jan 24 20:21:46 rio kernel: md: bind<sda2> Jan 24 20:21:47 rio kernel: md: bind<sdb2> Jan 24 20:21:47 rio kernel: md: running: <sdb2><sda2> Jan 24 20:21:47 rio kernel: raid1: raid set md1 active with 2 out of 2 mirrors Jan 24 20:21:47 rio kernel: md: considering sdb1 ... Jan 24 20:21:47 rio kernel: md: adding sdb1 ... Jan 24 20:21:47 rio kernel: md: adding sda1 ... Jan 24 20:21:47 rio kernel: md: hdg1 has different UUID to sdb1 Jan 24 20:21:47 rio kernel: md: hde1 has different UUID to sdb1 Jan 24 20:21:47 rio kernel: md: created md0 Jan 24 20:21:48 rio kernel: md: bind<sda1> Jan 24 20:21:48 rio kernel: md: bind<sdb1> Jan 24 20:21:48 rio kernel: md: running: <sdb1><sda1> Jan 24 20:21:48 rio kernel: raid1: raid set md0 active with 2 out of 2 mirrors Jan 24 20:21:48 rio kernel: md: considering hdg1 ... Jan 24 20:21:48 rio kernel: md: adding hdg1 ... Jan 24 20:21:48 rio kernel: md: adding hde1 ... Jan 24 20:21:48 rio kernel: md: md0 already running, cannot run hdg1 Jan 24 20:21:48 rio kernel: md: export_rdev(hde1) Jan 24 20:21:49 rio kernel: md: export_rdev(hdg1) Jan 24 20:21:49 rio kernel: md: ... autorun DONE. short story continues here... I use the full hd[eg] disks for the raid1 with only a single partition. The partitions are $ fdisk -l /dev/hde Disk /dev/hde: 300.0 GB, 300090728448 bytes 255 heads, 63 sectors/track, 36483 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0x1bd3d309 Device Boot Start End Blocks Id System /dev/hde1 1 36483 293049666 fd Linux raid autodetect When I plug the old hd[eg] raid back to be a single raid1 in the system, everything works fine. So nothing was actually broken. What did I do wrong? How can I just change md0 to md3 keeping everything else as is? Thank you, Clemens - 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