IO fencing in campus cluser architecture with two separate disk arrays
Dear Guru
We have two separate sites connected via SAN and network. Each site contains a server and a disk array. These all runs SFRAC 5.0 and Oracle RAC. IO fencing and data volumess are now configured at one of arrays (the first site). There are 3 coordinator disks. All c. disks are on the first array. We plan to mirror all the volumes for Oracle datafiles across the sites. But I have no idea how to avoid the second site suicide if the first site is powered off completly. We unable to mirror coordinate disks across the diffetent disk arrays at hardware level. VXVM mirroring is either prohibited. Placing 2 coordinators at the first array and 1 at the second doesn't solve the problem. If the first site goes down the second one is just unable to access 2 coordinate devices in the race and also panics and reboots.
I also found some stuff in the docs:
VERITAS Cluster Server 4.1 User’s Guide Solaris
"Note that you cannot use SCSI III fencing in a two-site campus cluster. You must have an additional site to distribute the coordinator disks"
Veritas™ Cluster Server Release Notes Solaris 5.0 Maintenance Pack 1
Campus cluster support ....
"Symantec recommends using I/O fencing in campus clusters"
Somewhere
"iSCSI devices are supported in IO fencing"
But we do have no another sites :) Are there any means in VCS like remote quorum systems? Do they support IO fencing?
Thank you in advance.
Hi Cool,
if you have a small test-lab or something like this (not in one of your datacenters), you can install a small server as iscsi-target, install 5.0MP3 at your cluster and use an iscsi-device as 3rd fencing disk. You can take a look at the release notes of VCS 5.0MP3, Page 15) (ftp://ftp.entsupport.symantec.com/pub/support/documentation/vcs_notes_sol.pdf) and the other VCS documents how to configure this.
This is a new feature. So I don't think that many customers use this at this moment and there aren't enough expriences with this, but it could be a possibility for you for the future.
Greets
Björn
Message Edited by bsobek on 10-28-2008 02:09 AM