When I try and disable auto detection, with kernel boot parameters, it goes ahead and auto assembles and runs anyway. The md= parameters seem to be noticed, but don't seem to have any other effect (beyond resulting in a dmesg). Here is the result $ dmesg | egrep 'raid|md:' Kernel command line: ro root=/dev/sda8 raid=noautodetect md=1,/dev/sdb2,/dev/sdc2,/dev/sdd2 md=2,/dev/sdb3,/dev/sdc3,/dev/sdd3 md=3,/dev/md1,/dev/hda2 md=4,/dev/md2,/dev/hda3 single md: Will configure md1 (super-block) from /dev/sdb2,/dev/sdc2,/dev/sdd2, below. md: Will configure md2 (super-block) from /dev/sdb3,/dev/sdc3,/dev/sdd3, below. md: Will configure md3 (super-block) from /dev/md1,/dev/hda2, below. md: Will configure md4 (super-block) from /dev/md2,/dev/hda3, below. md: Autodetecting RAID arrays. md: autorun ... md: considering sdd4 ... md: adding sdd4 ... md: sdd2 has different UUID to sdd4 md: sdd1 has different UUID to sdd4 md: adding sdc4 ... md: sdc2 has different UUID to sdd4 md: sdc1 has different UUID to sdd4 md: adding sdb4 ... md: sdb2 has different UUID to sdd4 md: sdb1 has different UUID to sdd4 md: hda3 has different UUID to sdd4 md: hda2 has different UUID to sdd4 md: created md2 md: bind<sdb4> md: bind<sdc4> md: bind<sdd4> md: running: <sdd4><sdc4><sdb4> md: raid0 personality registered for level 0 raid0: looking at sdd4 raid0: comparing sdd4(8409856) with sdd4(8409856) raid0: END raid0: ==> UNIQUE raid0: 1 zones raid0: looking at sdc4 raid0: comparing sdc4(8409856) with sdd4(8409856) raid0: EQUAL raid0: looking at sdb4 raid0: comparing sdb4(8409856) with sdd4(8409856) raid0: EQUAL raid0: FINAL 1 zones raid0: done. raid0 : md_size is 25229568 blocks. raid0 : conf->hash_spacing is 25229568 blocks. raid0 : nb_zone is 1. raid0 : Allocating 4 bytes for hash. md: considering sdd2 ... md: adding sdd2 ... md: sdd1 has different UUID to sdd2 md: adding sdc2 ... md: sdc1 has different UUID to sdd2 md: adding sdb2 ... md: sdb1 has different UUID to sdd2 md: hda3 has different UUID to sdd2 md: hda2 has different UUID to sdd2 md: created md1 md: bind<sdb2> md: bind<sdc2> md: bind<sdd2> md: running: <sdd2><sdc2><sdb2> raid0: looking at sdd2 raid0: comparing sdd2(8409856) with sdd2(8409856) raid0: END raid0: ==> UNIQUE raid0: 1 zones raid0: looking at sdc2 raid0: comparing sdc2(8409856) with sdd2(8409856) raid0: EQUAL raid0: looking at sdb2 raid0: comparing sdb2(8409856) with sdd2(8409856) raid0: EQUAL raid0: FINAL 1 zones raid0: done. raid0 : md_size is 25229568 blocks. raid0 : conf->hash_spacing is 25229568 blocks. raid0 : nb_zone is 1. raid0 : Allocating 4 bytes for hash. md: considering sdd1 ... md: adding sdd1 ... md: adding sdc1 ... md: adding sdb1 ... md: hda3 has different UUID to sdd1 md: hda2 has different UUID to sdd1 md: created md0 md: bind<sdb1> md: bind<sdc1> md: bind<sdd1> md: running: <sdd1><sdc1><sdb1> md: raid1 personality registered for level 1 raid1: raid set md0 active with 3 out of 3 mirrors md: considering hda3 ... md: adding hda3 ... md: hda2 has different UUID to hda3 md: created md4 md: bind<hda3> md: running: <hda3> raid1: raid set md4 active with 1 out of 2 mirrors md: considering hda2 ... md: adding hda2 ... md: created md3 md: bind<hda2> md: running: <hda2> raid1: raid set md3 active with 1 out of 2 mirrors md: ... autorun DONE. By way of context, this is kernel 2.6.20. I have set two striped (raid0) arrays, md1 and md2. Each of these is mirrored by with a single partition (hda2 and hda3) to form two raid 1 devices md3 and md4. This works perfectly if I start and stop the md3 and md4 arrays from mdadm. However the boot time autodetection always assembles degraded arrays (see the 1 out of 2 messages above). I presume this is because it only considers real physical partitions of type "Linux raid autodetect" and is not considering md1 and md2 as candidate devices to form further arrays. This is why I am trying to disable the autodetection, to see if directly specifying the raid configuration would help. This is driving me nuts. Maybe changing the type of the hda partitions would help? Any clues appreciated. Ian -- Ian Dall <ian@xxxxxxxxxxxxxxxxxxxxx> - 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