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 >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups >> > "QUADStor Storage Virtualization" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> > an >> > email to quadstor-vir...@googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "QUADStor Storage Virtualization" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to quadstor-virt+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "QUADStor Storage Virtualization" group. To unsubscribe from this group and stop receiving emails from it, send an email to quadstor-virt+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
