powerpath and pv link

[Camel_1]

Anyone has any idea? The server (HPUX 11i) has EMC power path installed, but also some VGs has pvlink configured. What will happend if the primary link in one of the disk is failed? Will EMC powerpath do the failover or by pvlink?

[John Poff]

Hi,

If you have EMC Powerpath installed and configured, it will handle a failover automatically. When I last used Powerpath, EMC recommended that you don't setup the PV links in your volume group. I had a link fail once and Powerpath handled it just fine, so I believe them.

JP

[Alzhy]

Simon,

Powerpath (like HPQ's SecurePath) takes care of pathing for you instead of PVLINKS. PVLINKS you use if the disks you're using can present themselves with dual paths. If an HBA fails or a Fibre cable is cut on your PowerPath presented LUNs from your EMC -- it will survive the cut and operate on whatever path(s) are remaining.. I understand Powerpath not only offers path protetion but load balancing as well.

If you have other PV's on the same boxen that have Alternate links on them (PVLINKS?)-- chances are they come from an array that does not have pathing software...

[Todd McDaniel_1]

I have Powerpath on 3 boxes and still utilize pvlinks just so I can keep track of my alternate pathing.


It doesn't hurt anything by having PVlinks alt paths defined. It is just a good way to monitor pathing...

The primary diff with PVlinks and Powerpath is that Powerpath will actually use ALL paths for pushing data down to the disk... giving you more i/o to the disk by dividing it down all paths

Unlike PVlinks which will push data down ONLY ONE path... and the alt path will never have data going down it until and unless the primary path dies.

Short answer is PVlinks will be overridden by PowerPath functionality.

[Sunil Sharma_1]

Hi,

Powerpath and PV link both used for redundency purpoes but in PP it can be configured in load sharing mode and data is pushed through both Path.

In case of failure it will switch to one path.

PP will get preference over PV link.


Sunil

[Stanimir]

Hi!
I thing there is no problems to
support both tools. The Powerpath
ensure failover & loadbalancing for
more than 1 paths. PVlink is also
available.
Regards.