topic VA7410 and VxVM Dynamic Multipathing..? in Disk Enclosures

VA7410 and VxVM Dynamic Multipathing..?

Vincent Abad — Fri, 25 Apr 2003 12:42:15 GMT

Hello Guys,

We are currently using a Virtual Array
7410, with Veritas Vomume Manager 3.5.
The dynamic multipathing feature is activated
and IO are splitted on the four available path
for a LUN(2 FC card per hosts + 2 FC switch with Fabric attach).
According to "Performance Path" definition in
User Guide, trying to reach LUN with not owning
controller can cause performance degradations.

Could experts give me a idea of the degradation
when LUNs are reached by 4 different paths?

Thanks,

--Vincent

Re: VA7410 and VxVM Dynamic Multipathing..?

Roger_22 — Fri, 25 Apr 2003 13:05:29 GMT

Very slight if any.

Re: VA7410 and VxVM Dynamic Multipathing..?

Eugeny Brychkov — Fri, 25 Apr 2003 13:11:20 GMT

Vincent,
which OS do you use? Windows or hpux or any other?
There can be only one active path (if not choosing 'load balancing' which is actually round-robin technique). LUNs created within RG1 should be accessed via VA C1 (C1.H1 or C1.H2 ports, does not matter, they're equal), LUNs within RG2 through C2 and either C2.H1 or C2.H2.
If you want to know degradation values I can not give them to you - you can try and figure these values experimentally, but the degradation occurs because when you access non-perfomance controller it internally reroutes data to perfomance controller
Eugeny

Re: VA7410 and VxVM Dynamic Multipathing..?

Vincent Abad — Fri, 25 Apr 2003 16:18:02 GMT

Hello,

We are using HP-UX 11.11 with rootability enabled (root disk managed by Vxvm)

Thanks,

--Vincent