The criteria for fencing a peer node is if a command in a write
sequence has timed out. At this point to continue with the current
write command is to fence the peer node to prevent any further changes
w.r.t to the write command, and then it is assumed to be safe to
continue with the write command.

Ofcourse it could be very well the case that the peer node is healthy
and the problem is in the network between the two. But even in that
case the only way to ensure continuity is fence the peer node and let
the current node handle the current and future writes.

Given the above, there isn't a good way of doing below (the keep mirroring part)

"Ilo network is down or saying server is OFF  / remote node services
are up (got a dedicated direct link for replication that could be used
to verify that)-> keep mirroring and don't takeover ownership"

Mirroring can only be synchronous if the writes complete successfully
at both the ends

The qmirrorcheck command does not necessarily have to be fence_ilo. It
can be a script which executes fence_ilo and evaluates various
conditions before determining a fence as successful or not. Also if
one fence (qmirrorcheck) command fails and if there are others
specified then they are also executed. The order is one listed by
qmirrorcheck. Maybe we should add an ordering here so that the fence
commands are always tried in the same order across reboots. Each fence
command is executed till one succeeds (an exit status of 0) If all
fence commands fails then the current writes and future writes are
failed till there is a reconnect to the peer node when the node or
network is up (The reconnect isn't automatic and occurs only on the
peer quadstor service startup)


On Tue, Jan 31, 2017 at 12:42 AM, Fabien Rouach <fabien.rou...@gmail.com> wrote:
> Thanks,
> Was easier than expected
>
> Now can i fence on several "criterias" and add some logic?
> I'd like to check if remote node Quadstor Service is running
>
> So i could evaluate cases like:
> Ilo network is down or saying server is OFF  / remote node services are up
> (got a dedicated direct link for replication that could be used to verify
> that)-> keep mirroring and don't takeover ownership
> Ilo network return server is ON  / remote node services are down -> takeover
> ownership
>
>
> Le vendredi 27 janvier 2017 13:12:21 UTC-5, quadstor a écrit :
>>
>> The fence command usage for ILO isn't different from the other examples
>>
>> /quadstor/bin/qmirrorcheck -a -t fence -r 10.0.13.151 -v
>> '/usr/sbin/fence_ilo -a 10.0.13.151  -l Admin -p Password'
>>
>> Where 10.0.13.151 is the node we are trying to fence. You can test if
>> the fence command is communicating correctly with by sending '-o
>> status' to fence_ilo. (Note that its most likely
>> fence_ilo2/fence_ilo3/fence_ilo4)
>>
>>
>> On Wed, Jan 25, 2017 at 12:58 AM, Fabien Rouach <fabien...@gmail.com>
>> wrote:
>> > Hi,
>> > I'm actually building a test lab with Quadstor storage virtualisation.
>> > Got 2 node (physicals machine in HA mirroring
>> >
>> > Would like to config fencing but all exemple i found used VM nodes, and
>> > part
>> > of the setup is done on the VM host.
>> > Any guide / exemple available on how to do it with physical machine.
>> >
>> > I'd like to fence using network interface dedicated to replication.
>> > Optionally, I'like to fence using iLo interfaces (they are HP machines),
>> > seen it's possible but seams complicated, anyone had already done that?
>> >
>> > Is it possible to fence on 2 "criteria" (replication interface not
>> > beeing
>> > reachable + iLo ?
>> >
>> > Thanks
>> >
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