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EVA5000 and OVMS multi-pathing

Jiri Koutnik
Advisor

EVA5000 and OVMS multi-pathing

Hello,
I have EVA5k with firmware 4.07, so ACTIVE-ACTIVE mode. OVMS server connected to the storage, using native multi-pathing to balance VDISKs over 2 HBA.
Question is, do i have to set also Preferred path/mode in Command View and to which value ?
possibilities are:
1) No preference
2) Path A/B Failover only
3) Path A/B Failover/failback

I understand what those possibilities mean, but I am not sure, which one is correct to set on ?!
And is there any different to setting this on EVA5k with firmware 3.028 ?

thanx very much indeed for your help.

Jiri
2 REPLIES
Uwe Zessin
Honored Contributor

Re: EVA5000 and OVMS multi-pathing

The latest user guides for active/passive firmware (VCS 3.110) and active/active firmware (VCS V4.100) both say: all settings allowed - Recommended setting: Path A/B - Failover/Failback.

If the OpenVMS release is current and equiped with current device drivers, it understands optimized and non-optimized paths, which can avoid unneeded traffic across the mirror port.
.
Jiri Koutnik
Advisor

Re: EVA5000 and OVMS multi-pathing

Hi,

we have OVMS 8.2, so we use native VMS multi-pathing to balance traffic over HBA. But it doesnt correspond to correct balancing on EVA controllers, It means, if I prefer VDISK on VMS and the same disk is mananeged by controller then I can see READ MISSes so I have to change path on OVMS after READ MISS changes to READ HIT. I have so logical algoritmus to prefer path on OVMS, but it doesnt switch managing controller, so that why my balancing from OVMS is not quite correct. I thought if I set on NO PREFERENCE on VDISK I would be able to do this. Do I have to also balance VDISK in Command View through SSSU or somehow ?