PVLinks v Securepath failover - only 1 way? - EVA8000

[A.W.R]

Hi,

We have an rx6600 with HP-UX 11i v2 with dual fc controllers connected to a SAN with an EVA8000 storage subsystem.

THe rx6600 is using PVlinks for to handle the FC controller redundancy.

We have found that with PVlinks the LUNs will only failover once. PVlinks does not failback when the primary path is restored. We need to do a reboot to achieve this. Is this the correct behaviour of PVlinks?

We have been told that Securepath will sort out this problem, will Securepath be a better option?

Appreciate any input you can share.

Thanks
Andrew

[Torsten.]

You should have at least 4 pathes (1 primary - 3 alternate) to a vdisk. If one path fails you will see this path as unavailable in vgdisplay. Once it come back, it should be available again.

[Court Campbell]

I personally like securepath. I like the load balancing features it has. I know you can load balance with PVlinks, but the options you have for load balancing like round-robin and least I/O seem worth it.

[Torsten.]

Of course this features are really nice, I assume for this reason they are in hp-ux 11.31 ;-)

[Basheer_2]

Hi Andy,

I strongly recommend secure path ( which is going away in favor of bill's DMIO). i dont know why you guys are using pvlinks in a EVA8000

[Jean-Marc Eurin · Accepted solution]

Hello Andrew,

For PVlinks to failback to the primary path, you need to have the "autoswitch" set on the PV.

You can check the autoswitch status using 'pvdisplay /dev/dsk/cxtydz' and you can set it using the 'pvchange -S y /dev/dsk/cxtydz'.

Note that recent LVM patches have improved the failover times of PVlinks.

Regards,

Jean-Marc