On Thu, 25 Feb 2010 09:41:41 +0100 Piergiorgio Sartor <piergiorgio.sartor@xxxxxxxx> wrote: > Hi, > > > I certainly believe you. > > thank you! > > > That is really odd! Both the kernel ext3 module (triggered by '-text3') > > and the 'mount' program use exactly the same test - look for the magic > > number in the superblock at 1K into the device. > > Today I tried: blkid -p /dev/md1 (this time the live CD > autoassembled the md device) and it returned something > like: ambivalent result (probably more than one filesystem...) > > Strange thing is that, the HDDs were brand new, no older > partitions or filesystem were there. > > Anyway, I've one small correction, the RAID is not 10 f2, > on this PC, but (due to different installation) a RAID-1 > with superblock 0.9 and the device partitions are set > to 0xFD (RAID autoassemble). > > > Would you be able to get the first 4K from each device in the raid10: > > dd if=/dev/whatever of=/tmp/whatever bs=1K count=4 > > > > and the tar/gz those up and send them to me. That might give some clue. > > Unless the raid metadata is 1.1 or 1.2 - then I would need blocks further in > > the device, as the 'data offset'. > > The --detail output of the array might help too. > > I dumped the first 4K of each device, they're identical > (so no mismatch there, at least), I'll send them to you, > together with the detail output. Thanks. I finally had a look at these (sorry for delay). If you run "file" on one of the dumps, it tells you: $ file disk1.raw disk1.raw: Minix filesystem Which isn't expected. I would expect something like $ file xxx xxx: Linux rev 1.0 ext3 filesystem data, UUID=fe55fe6f-0412-4a0a-852d-a0e21767aa35 (needs journal recovery) (large files) for an ext3 filesystem. Looking at /usr/share/misc/magic, it seems that a Minix filesystem is defined by: 0x410 leshort 0x137f Minix filesystem i.e. the 2 bytes at 0x410 into the device are 0x137f, which exactly what we find in your dump. 0x410 in an ext3 superblock is the lower bytes of "s_free_inodes_count", the count of free inodes. Your actual number is 14881663, which is 0x00E3137F. So if you just add or remove a file, the number of free inodes should change, and your filesystem will no longer look like a Minix filesystem and your problems should go away. I guess libblkid et-al should do more sanity checks on the superblock before deciding that it really belongs to some particular filesystem. But I'm happy - this clearly isn't a raid problem. NeilBrown -- 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
