Hi, My configuration is following: raid6= 2TB + 2TB + raid5(4*500GB+missing) + missing. This can be hardly called a redundancy, this is due to problems with SATA controllers. I have third 2TB and two 500GB discs just waiting to be plugged in, but currently I can't - my current controllers don't work with them well (I am looking for controllers that will communicate with them well, currently I will RMA Sil3114, which I bought today). A similar configuration was previously working good: raid6 = 2TB + 2TB + raid6(5*500GB+missing) + missing. But one of those 500GB discs in raid6 above had problems communicating with SATA controllers and I decided to remove it. Also I decided to switch this sub-array from raid6 to radi5. In the end it was easiest to recreate this array as raid5, with the problematic disc removed. And then the problems started happening. I created that raid5(4*500GB+missing) sub-array. Added it to BIG raid6 array, it took 2 days to resync. Then after reboot - to my surprise the sub-array was kicked out of BIG raid6. And now, after each reboot I must do following: (The sub-array is /dev/md6, and BIG array is /dev/md69) # cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md6 : inactive sdg1[0](S) sdc1[5](S) sde1[3](S) sdh1[2](S) sda1[1](S) 2441914885 blocks super 1.1 md69 : active raid6 sdd3[0] sdf3[1] 3901977088 blocks super 1.1 level 6, 128k chunk, algorithm 2 [4/2] [UU__] bitmap: 15/15 pages [60KB], 65536KB chunk md0 : active raid1 sdf1[6] sdb1[8] sdd1[9] 979924 blocks super 1.0 [6/3] [UU___U] md2 : active (auto-read-only) raid1 sdb2[8] 4000176 blocks super 1.0 [6/1] [_____U] bitmap: 6/8 pages [24KB], 256KB chunk unused devices: <none> # mdadm --run /dev/md6 mdadm: started /dev/md6 # cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md6 : active (auto-read-only) raid5 sdg1[0] sdc1[5] sde1[3] sda1[1] 1953530880 blocks super 1.1 level 5, 128k chunk, algorithm 2 [5/4] [UU_UU] bitmap: 4/4 pages [16KB], 65536KB chunk md69 : active raid6 sdd3[0] sdf3[1] 3901977088 blocks super 1.1 level 6, 128k chunk, algorithm 2 [4/2] [UU__] bitmap: 15/15 pages [60KB], 65536KB chunk md0 : active raid1 sdf1[6] sdb1[8] sdd1[9] 979924 blocks super 1.0 [6/3] [UU___U] md2 : active (auto-read-only) raid1 sdb2[8] 4000176 blocks super 1.0 [6/1] [_____U] bitmap: 6/8 pages [24KB], 256KB chunk # mdadm --add /dev/md69 /dev/md6 mdadm: re-added /dev/md6 # cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md6 : active raid5 sdg1[0] sdc1[5] sde1[3] sda1[1] 1953530880 blocks super 1.1 level 5, 128k chunk, algorithm 2 [5/4] [UU_UU] bitmap: 4/4 pages [16KB], 65536KB chunk md69 : active raid6 md6[4] sdd3[0] sdf3[1] 3901977088 blocks super 1.1 level 6, 128k chunk, algorithm 2 [4/2] [UU__] [>....................] recovery = 0.0% (75776/1950988544) finish=1716.0min speed=18944K/sec bitmap: 15/15 pages [60KB], 65536KB chunk md0 : active raid1 sdf1[6] sdb1[8] sdd1[9] 979924 blocks super 1.0 [6/3] [UU___U] md2 : active (auto-read-only) raid1 sdb2[8] 4000176 blocks super 1.0 [6/1] [_____U] bitmap: 6/8 pages [24KB], 256KB chunk It kind of defeats my last point of redundancy - having to re-add /dev/md6 upon each reboot. This dangerous situation shouldn't last longer than a week or two, I hope, until I get a working SATA controller and attach remaining drives. But If you could help me here, I would be grateful. Is it possible that the order in which the arrays were created, matters? Because when it worked I created the sub-array first, and then I created the BIG array. And currently the sub-array is created after the BIG one. best regards -- Janek Kozicki http://janek.kozicki.pl/ | -- 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