topic Re: Auto Suspend attribute on DR Group in Disk Enclosures

Auto Suspend attribute on DR Group

Kehad Snydewel — Thu, 12 Mar 2009 11:21:14 GMT

Hi Guru's,

when auto suspend mode is enabled on a DR Group, what will happen to the source vdisks within the DR Group if the destination EVA is not reachable?

i had power maintenance at our DR Site and had to shutdown the EVA6000 at DR and auto suspend was enabled on all DR Groups. i have DR groups replicating from DR to PRD and visa versa.

i have HPUX 11.11 servers at both Production and DR Sites.

while the EVA at DR were still down, the Production hosts (source) we not able to access their LUNs and i were not able to ssh or telnet to the hosts at production. i accessed the console of the HPUX servers via the MP and noticed path failures in the syslog and secure path showed all paths to the vdisks/LUNs as failed.

i manually had to suspend the replication on the DR Group and the HPUX servers were able to access the vdisks again. secure path showed active paths/LUNs again.

should auto-suspend not halt the i/o to the destination vdisk automatically?

why was it not possible for the hosts connecting to the source vdisks within a DR Group no able to access their LUNs. all other LUNs not in a DR Groups were accessable.

firmware version of the controllers is 6.100.

Re: Auto Suspend attribute on DR Group

Juan B.S.R. — Fri, 13 Mar 2009 07:22:54 GMT

Hi.
You must take a look to the "Failsafe mode" parameter at the General tab for the DR Group properties.
If "Failsafe mode" is enable all I/O from production hosts to source, or destination, vdisk are stoped to preserve data consistency across all hosts.

You must disable "Failsafe mode" to avoid this situation, if really you want.
Take a look to this explanation (Overview of EVA and Continuous Access EVA Concepts)http://docs.hp.com/en/B7660-90019/ch04s02.html.
I hope this can help you.
Regards.

Re: Auto Suspend attribute on DR Group

Kehad Snydewel — Fri, 13 Mar 2009 11:23:40 GMT

"fail safe" mode are disabled on all DR groups. this is something i checked as well.

Re: Auto Suspend attribute on DR Group

Dileep.. — Sun, 15 Mar 2009 17:34:15 GMT

As far as i know autosuspend is the feature just to stop the "automatic" full copy while a replication partner goes offline and come back online after the failover. this is to give a chance for users to take the backup on the "current" detsination EVA before full copy.refer page49 on below link
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c01680823/c01680823.pdf

Also i could see that this is only supported by xcs6.200 (refer page26 on below link)
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c01680632/c01680632.pdf

i believe , it requires bit deep analysis to findout the reason for I/O error.i would suggest you to log a case with HP to findout the reason for I/O error.

Regards
Dileep

Re: Auto Suspend attribute on DR Group

Kehad Snydewel — Wed, 18 Mar 2009 07:16:15 GMT

thanks Dileep,

auto susspend is supported as from XCS6.2 and not on 6.1x on an EVA4/6/8K.

Re: Auto Suspend attribute on DR Group

Kehad Snydewel — Wed, 18 Mar 2009 07:20:02 GMT

controller firmware needs to be on XCS6.2 which supports auto suspend. my XCS is currently on 6.100