Hi! A little history: 2 years ago I was really excited to find out that mdadm is so powerful so it even can reshape arrays so you can start with a smaller array and the grow it as you need. I've bought 3x1Tb drives and made RAID-5. It was fine for a year.

Then I bought 2x more, and tried to reshape to RAID-6 out of 5 drives, and due to some mess with superblock versions, lost all content. Had to rebuild it from scratch, but 2Tb of data were gone.

Yesterday I bought 2 more drives, and this time I had everything: properly built array, UPS. I've disabled write intent map, added 2 new drives as a spare and run a command to grow array to 7-disk.

It started working, but speed was ridiculously slow, ~100kb/sec. AFter processing first 37Mb at such an amasing speed, one of old HDDs fails. I properly shutdown PC and disconnected failed drive. After bootup it appeared it recreated intent map as it was still in mdadm config, so I removed it from config and rebooted again.

Now all I see is that all mdadm processes deadlocks, and don't do anything.

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 1937 root      20   0 12992  608  444 D    0  0.1   0:00.00 mdadm
 2283 root      20   0 12992  852  704 D    0  0.1   0:00.01 mdadm
 2287 root      20   0     0    0    0 D    0  0.0   0:00.01 md0_reshape
 2288 root      18  -2 12992  820  676 D    0  0.1   0:00.01 mdadm

And all I see in mdstat is:

$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid6 sdb1[1] sdg1[4] sdf1[7] sde1[6] sdd1[0] sdc1[5]
      2929683456 blocks super 1.2 level 6, 1024k chunk, algorithm 2 [7/6] [UU_UUUU]
      [>....................]  reshape =  0.0% (37888/976561152) finish=567604147.2min speed=0K/sec

I've already tried mdadm 2.6.7, 3.1.4 and 3.2 - nothing helps. Did I lost my data again? Any suggestions how can I make it work? OS is Ubuntu Server 10.04.2...

PS. Needless to say that data is unaccessible - I cannot mount /dev/md0 as save the most valuable data.

You can see my disappointment - the very specific thing I was excited about failed twice taking 5Tb of my data with it.