/dev/md2 stopped after changing SAS controller

[Louis-David Mitterrand <vindex+lists-linux-raid@apartia.org>]

Hi,

I've been having very bad performance with an LSISAS2008 controller
attached to 8 WD Caviar Black 1TB disks.

So I swapped it out for an Apaptec RAID 6805 with the same disks and now
my /dev/md2 won't start.

	May 13 17:14:37 zenon kernel: md: sdh3 does not have a valid v1.2 superblock, no
	t importing!
	May 13 17:14:37 zenon kernel: md: md_import_device returned -22
	May 13 17:14:37 zenon kernel: md: sda3 does not have a valid v1.2 superblock, no
	t importing!
	May 13 17:14:37 zenon kernel: md: md_import_device returned -22
	May 13 17:14:37 zenon kernel: md: sdf3 does not have a valid v1.2 superblock, no
	t importing!

	Etc...

Both controllers are used without any configuration. I just use the
separate disks for soft raid.

Each disk is configured thus:

	Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
	255 heads, 63 sectors/track, 121601 cylinders
	Units = cylinders of 16065 * 512 = 8225280 bytes
	Sector size (logical/physical): 512 bytes / 512 bytes
	I/O size (minimum/optimal): 512 bytes / 512 bytes
	Disk identifier: 0x05022e04

	   Device Boot      Start         End      Blocks   Id  System
	/dev/sda1               1          32      257008+  fd  Linux raid autodetect
	/dev/sda2              33       17500   140311710   fd  Linux raid autodetect
	/dev/sda3           17501      121601   836191282+  fd  Linux raid autodetect

And my raid config used to be:

	Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath] [faulty] 
	md2 : active raid6 sdc3[0] sdd3[7] sdf3[6] sdb3[5] sdh3[4] sda3[3] sdg3[2] sde3[1]
		  5017138176 blocks super 1.2 level 6, 512k chunk, algorithm 2 [8/8] [UUUUUUUU]
		  bitmap: 0/7 pages [0KB], 65536KB chunk

	md1 : active raid6 sdc2[0] sdd2[7] sdf2[8] sdb2[5] sdg2[4] sdh2[3] sda2[2] sde2[1]
		  841863168 blocks super 1.2 level 6, 512k chunk, algorithm 2 [8/8] [UUUUUUUU]
		  bitmap: 2/2 pages [8KB], 65536KB chunk

	md0 : active raid1 sdc1[0] sdd1[7] sdf1[6] sdh1[5] sde1[4] sdb1[3] sda1[2] sdg1[1]
		  256896 blocks [8/8] [UUUUUUUU]
		  bitmap: 0/1 pages [0KB], 65536KB chunk

	unused devices: <none>


Going back to the LSISAS2008 controller makes /dev/md2 come back.

Any idea why the Adaptec wont let me use /dev/md2? Going into its
bios configuration menu I see a JBOD mode but it seems each disk has to
be "initialized" in order to be used in that mode.

Meanwhile the disks are used in "legacy" mode:

	May 13 17:09:57 zenon kernel: scsi 0:0:0:0: Direct-Access     Adaptec  6805 Legacy      V1.0 PQ: 0 ANSI: 2


Thanks,