topic Re: SGLX and RHCS: fence device Vs lock lun in Operating System - Linux

SGLX and RHCS: fence device Vs lock lun

Jun Yu — Tue, 13 Jun 2006 17:06:39 GMT

Hello all,

The latest RHCS use power switch/SAN switch/remote controller as it's fencing device and removed the support of quorum LUN which exists in previous RHELv3.

I just wonder in a two node cluster configuration, compare SGLX with lock lUN and RHCS with it's own fencing mechanism, which one is more reliable? Especially when the heartbeat is broken(even if the bonding is failed).I've read from Red Hat cluster mail list that Red Hat cluster's new fencing mechanism has less latency than quorum LUN.

Regards,
Jun,

Re: SGLX and RHCS: fence device Vs lock lun

Steven E. Protter — Wed, 14 Jun 2006 00:57:14 GMT

Shalom Jun,

You can actually operate RHCS without a valid fence device with 4.0.

I work with both SG and RHCS and find them both to be quite difficult. Its important to use only supported hardware with RH, should you choose to use a fence device. I've often had to write custom fence control/acknowledge scripts which I really should not have to do.

The Lock disk is solid, reliable and I've never had to write custom code to check it under SG.

SEP

Re: SGLX and RHCS: fence device Vs lock lun

Jun Yu — Wed, 14 Jun 2006 13:04:16 GMT

Thanks Steven,

Does Redhat consider their latest fencing mechanisms is more "advanced" than previous quorum disk/lun technology or compare to other company's traditional solution(such as SGLX)?

I read more issue reports from RHCS mailing lists about fencing, so it seems a bit interesting of RHCS's design & fence implementation.

By the way, do you know if there are more community resource(web forum, mailing list, newsgroup) that dedicate to HP MC/SG(for Unix and Linux)? Appreciate if you can share.

HP's ITRC forum is the only resource I've found that have a board to discuss MC/SG.

Regards,