[Gluster-devel] all-null pending matrix again

[Emmanuel Dreyfus]

Hi

I tested 3.4.1 on a long run ang got a spurious split brain with all-null
pending matrix again:

[2013-09-30 00:25:12.962127] E
[afr-self-heal-common.c:197:afr_sh_print_split_brain_log]
0-gfs341-replicate-1: Unable to self-heal contents of
'/manu/netbsd/usr/src/lib/libpuffs/obj/dispatcher.pico' (possible
split-brain). Please delete the file from all but the preferred subvolume.-
Pending matrix:  [ [ 0 0 ] [ 0 0 ] ]

The bug is described with log files here:
https://bugzilla.redhat.com/show_bug.cgi?id=1005526

We previously thought that it was caused by heterogeneous setup (i386 +
amd64), but it is not the case in my latest test. The only known workaround so
far is to disable eager locks.

The split brain is real, as shown below. What I do not really understand is
why I have 4 copies of the file, as this is a 2x2 stripped-replicated volume.
The first set of replicas are fine, the second set has two file filled with
zeros, one wih correct size, the other being truncated.

silo:/export/wd2a/manu/netbsd/usr/src/lib/libpuffs/obj/dispatcher.pico
-rw-r--r--  2 manu  manu  11916 Sep 30 02:23 dispatcher.pico
SHA1(dispatcher.pico) = b512c2924194ab9d001aec402ef037225f9a6e6d

hangar:/export/wd1a/manu/netbsd/usr/src/lib/libpuffs/obj/dispatcher.pico
-rw-r--r--  2 manu  manu  11916 Sep 30 02:23 dispatcher.pico
SHA1(dispatcher.pico) = b512c2924194ab9d001aec402ef037225f9a6e6d

hangar:/export/wd3a/manu/netbsd/usr/src/lib/libpuffs/obj/dispatcher.pico
-rw-r--r--  2 manu  manu  11916 Sep 30 02:23 dispatcher.pico
SHA1(dispatcher.pico) = 3bdf1048eff02260594f7385449dcc37bd09b78f
NB: filled with zeroes

debacle:/export/wd1a/manu/netbsd/usr/src/lib/libpuffs/obj/dispatcher.pico
-rw-r--r--  2 manu  manu  11049 Sep 30 02:23 dispatcher.pico
SHA1(dispatcher.pico) = 5357efe9fa5299b59a279b32ce804767c6ffc116
NB: filled with zeroes

Is it possible to have the same file on different stripes in other situations
than during a rename operation?


-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu at netbsd.org