> Where there any kernel message (view with 'dmesg') at this time? Mar 21 00:27:45 brahma kernel: md: invalid raid superblock magic on sdd Mar 21 00:27:45 brahma kernel: md: sdd does not have a valid v0.90 superblock, not importing! Mar 21 00:27:45 brahma kernel: md: md_import_device returned -22 What is much more interesting, is that I rebooted the machine, and 'mdadm --examine' started working again (producing output). I then retried the 'mdadm -A' command and that went through as well. I did not run any other command that could have written anything to the hard disk. This is an x86_64 machine - Linux brahma.skynet.xc 2.6.23.15-137.fc8 #1 SMP Sun Feb 10 17:03:13 EST 2008 x86_64 x86_64 x86_64 GNU/Linux I cannot recall if the raid set was originally created on a 32 or a 64 bit O.S. Is there any other diagnostic I can try ? regards, -pradeep. --- NeilBrown <neilb@xxxxxxx> wrote: > On Fri, March 21, 2008 7:26 am, Pradeep wrote: > > Hi, > > It appears that a 'mdadm -A' command erased the superblocks on my > > disks. > > Could you please take a look and let me know if I did something wrong ? > > > > (I was adding 2 disks that were in a raid 1 set to a new machine running > > fedora 8.) > > Briefly, I issued an 'mdadm --examine /dev/sdd1' command to check the > > disks in my raid 1 > > array. > > (repeat similar command for /dev/sde1) > > > > Then I issued 'mdadm -A -v -u '400f8c5f:045827ea:f72fe561:698ccea2' > > /dev/md0' > > which errored out because it was looking at /dev/sdd instead of /dev/sdd1 > > > > This isn't why it errored out. It looked at sdd and found nothing there. > It also looked at various other devices and found nothing usable there. > That is perfectly normal. > > What is strange is that it found sdd1 and sde1 in /proc/partitions, > but couldn't find names for them in /dev, so it reports them as > 8:65 and 8:49 > > However when you ran the "--examine", it did find /dev/sdd1 in > /dev with the correct major/minor numbers. So something must > have happened between those two commands. > > Also, I cannot think why it is reporting "Invalid argument" and > failing to add the devices to the array. > Where there any kernel message (view with 'dmesg') at this time? > > NeilBrown > > > > ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ -- 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