What is Splitbrain mechanism on SFWHA

[Tonado_wang]

Hi

What is Splitbrain mechanism on SFWHA( VCS on windows， using VxVM to manage shared storage) ？

As we know that :

1) IO-Fencing is not supported on Windows

2) SFWHA is support SCSI3 reservation PGR ( by tune on it in VEA-->Control panel--> system settings)

My question is

1) What is the Splitbrain mechanism on Windows SFWHA( by using VxVM manage shared disks) ?

2) Does SCSI3 reservation PGR is involved in the Splitbrain mechanism ?

Thanks

[Tonado_wang]

I mean : Infoscale enterprise on Windows ( SFWHA is lagacy name which in old versions)

[RiaanBadenhorst]

Hi,

in the windows space we don't have many tools to fight it, you'll rely on heartbeats primarily.

https://www.veritas.com/support/en_US/article.100019784

[Tonado_wang]

Thanks for your reply. 

Does SCSI3 reservation PGR is involved in the Splitbrain mechanism once all the heartbeat failed ?

[Mouse]

My understanding of SCSI-3 PGR is that imported disk groups would have a reservation placed, this is what is common between SFW and SF/HA on Unix.

Fencing is on top of SCSI-3 PGR. Again, to my understanding, reservations placed on disks would not allow a node which does not have keys to access disks automatically so a protection from data corruption is still there even without fencing, this should be the case in SFW/HA. But this feature alone is not enough for membership arbitration which is what effectively fencing does in Unix.

[Mouse · Accepted solution]

Found a good article explaining how it works in SFW/HA https://www.veritas.com/support/en_US/article.100022090