Hi Alfredo, For the moment, it is a POC, and I'm basing the whole thing on the RAID1 mdadm resource script I have submitted.
I'm also considering the possibility of using a Continuous Access (HP arrays like EMC's SRDF functionnality) but still need raid manager binaries etc ... and the time and inspiration to write the scripts. Ideally, I would tend to privilege LVM mirror, but it still has some points to be addressed as SPOF on mirrorlog etc... Brem 2009/9/2 Moralejo, Alfredo <[email protected]> > What kind of data replication will be used? > > > > Regards, > > > > Alfredo > > > ------------------------------ > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *brem belguebli > *Sent:* Wednesday, September 02, 2009 1:14 PM > *To:* linux clustering > *Subject:* [Linux-cluster] Re: Fencing question in geo cluster (dual sites > clustering) > > > > Hi, > > > > Any idea or comment on this. > > > > Thanks > > > > Brem > > > <http://1.bp.blogspot.com/_mz9iIrpv_qo/Si1NmQ2QNmI/AAAAAAAADP4/fV8j_ZsGlBw/s1600-h/Drawing1.png> > > > > > CF link attached to diagram that describes the setup. > > http://1.bp.blogspot.com/_mz9iIrpv_qo/Si1NmQ2QNmI/AAAAAAAADP4/fV8j_ZsGlBw/s1600-h/Drawing1.png > > > 2009/8/21, brem belguebli <[email protected]>: > > Hi, > > > > I'm trying to find out what best fencing solution could fit a dual sites > cluster. > > > > Cluster is equally sized on each site (2 nodes/site), each site hosting a > SAN array so that each node from any site can see the 2 arrays. > > > > Quorum disk (iscsi LUN) is hosted on a 3rd site. > > > > SAN and LAN using the same telco infrastructure (2 redundant DWDM loops). > > > > In case something happens at Telco level (both DWDM loops are broken) that > makes 1 of the 2 sites completely isolated from the rest of the world, > > the nodes at the good site (the one still operationnal) won't be able to > fence any node from the wrong site (the one that is isolated) as there is no > way for them to reach their ILO's or do any SAN fencing as the switches at > the wrong site are no more reachable. > > > > As qdiskd is not reachable from the wrong nodes, they end up being rebooted > by qdisk, but there is a short time (a few seconds) during which the wrong > nodes are still seing their local SAN array storage and may potentially have > written data on it. > > > > Any ideas or comments on how to ensure data integrity in such setup ? > > > > Regards > > > > Brem > > > > -- > Linux-cluster mailing list > [email protected] > https://www.redhat.com/mailman/listinfo/linux-cluster >
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