[Linux-cluster] multipath/gfs lockout under heavy write
mmatus at dinha.acms.arizona.edu
Tue Jan 25 09:20:50 UTC 2005
David Teigland wrote:
>On Tue, Jan 25, 2005 at 01:41:54AM -0700, Marcelo Matus wrote:
>>>In the past, GFS would immediately panic the machine when it saw i/o
>>>errors. Now it tries to shut down the bad fs instead. After this happens
>>>you should be able to unmount the offending fs, leave the cluster and
>>>reboot the machine cleanly.
>>I have a question about your last comment. We did the following
>>experiment with GFS 6.0.2:
>>1.- Setup a cluster using a unique GFS server and gnbd device (lock_gulm
>>master and gnbd_export in the same node).
>>2.- Fence out a node manually using fence_gnbd.
>>then we observed two cases:
>>1.- If the fenced machine is not mounting the GFS/gnbd fs, but only
>>importing it, then we can properly either reboot or restart the GFS
>>services with no problem.
>>2.- If the fenced machine is mounting the GFS/gnbd fs, but with no
>>process using it, almost everything produces a kernel panic, even just
>>unmounting the unused fs. In fact the only thing that works, besides
>>pushing the reset button, is 'reboot -f', which is almost the same.
>>So, when you say "In the past", do you refer to GFS 6.0.2 ?
>I was actually referring to the code Lazar is using which is the next, as
>yet unreleased, version of GFS from the public cvs. Your situation could
>be explained similarly, like this:
>- running fence_gnbd causes the node to get i/o errors if it tries to use
>- if the node has GFS mounted, GFS will try to use gnbd
>- when GFS 6.0.2 sees i/o errors it will panic
>If you don't have GFS mounted, the last two steps don't exist and there's
Thanks, that clarify to us that we don't have any error in our
Then, the question is:
the new behaviour as you described, will be only present in the CVS
version (kernel 2.6)
or it will be also back ported to the current GFS 6.0.2 version (kernel
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