After realizing my stupid error in specifying the bitmap during array creation, I've triggered a couple of 100% repeatable bugs with this scenario.
BUG 1)When I create an array without a bitmap and add it after the array is synced, all works fine with any filesystem. If I create WITH the internal bitmap and use xfs, it chokes at mount time with:
mount: wrong fs type, bad option, bad superblock on /dev/md0,
or too many mounted file systems
xfs_check also dies with:
[root@gtmp01 GTMP]# xfs_check /dev/md0
xfs_check: unexpected XFS SB magic number 0x00000000
xfs_check: read failed: Invalid argument
xfs_check: data size check failed
/usr/sbin/xfs_check: line 28: 30580 Segmentation fault
xfs_db$DBOPTS -i -p xfs_check -c "check$OPTS" $1
Strangely, whatever the underlying cause is, ext3 seems immune (at least in brief testing) to this. I can create and mount an ext3 filesystem on top of the array that xfs dies trying to mount.
In the case where the array is created with bitmap at build time, if I wait until resync is completed, do a 'mdadm -Gb none' followed by 'mdadm -Gb internal', I can then safely create the XFS filesystem and mount it.
BUG 2)Another bitmap failure during create time: MDADM dies with an error after creating the array, when it tries to assemble it, with an external-file bitmap (on ext3):
[root@gtmp01 GTMP]# mdadm -C /dev/md0 -f --chunk=512 --level=10 -n14 -po2 -e1.2 -bESC[1P^M[root@gtmp01 GTMP]# mdadm -C /dev/md0 -f --chunk=512 --level=10 -n14 -po2 -e1.2 -b/var/tmp/bitmap /dev/mapper/mpath*
mdadm: RUN_ARRAY failed: Cannot allocate memory
mdadm: stopped /dev/md0
The array can be manually assembled, but it does not load with the
bitmap, even when specifying it with 'mdadm -A /dev/md0 -b/var/tmp/bitmap'.
For reference, I'm running: mdadm - v2.5.3 - 7 August 2006 mkfs.xfs version 2.8.11 kernel 2.6.18 (Opteron, x86_64, SMP)I've attached typescript of the sessions where I run through all of these scenarios, as well as an strace of the "mdadm -C -b/var/tmp/bitmap" where it fails to assemble the array. Also is a file with the superblock detail on all the member devices.
Again, more than happy to help test patches and any scenarios. Cheers, /eli
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mdadm-create-array-with-bitmap-ext3-success.log.gz
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mdadm-create-array-with-bitmap-failure.log.gz
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mdadm-create-array-with-bitmap-failure.superblocks.gz
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mdadm-create-array-with-bitmap_externalfile-fails.log.gz
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mdadm-create-array-with-bitmap_externalfile-fails.strace.gz
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mdadm-create-array-without-bitmap-success.log.gz
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