How many paths?

[LaurenMalhoit]

Hi All,

How do I confirm that I have the correct amount of paths for iSCSI storage?  For instance if I have two physical nics set up in a 1:1 ratio with the storage, using 10GB ethernet, and 4 targets...how many paths should I have?

Thanks!

[mcowger]

Its extremely dependent on the nature of your storage array and on how your networking is done.

We'd need that information to give a reasonable guess.  A bare minimum would be 4 in this configuration, but I can imagine scenarios where you'd be able to see 8 paths.

And by target, to confirm, you mean the SCSI meaning of the word target (and not LUN), yes?

[LaurenMalhoit]

Yes, the iSCSI target.  I guess I'm looking for a general answer to figure it out in the future.  But I'm happy to answer any other questions to make it more specific.  Let's say it's an EMC VNX.  Let's say it's set up with 10GB, with two NICs for storage setup with two iSCSI "networks" (iSCSI 1 = Nic1 Active/Nic2 Unused; iSCSI2 = Nic2 Active/Nic1 Unused).

Thanks!

[mcowger]

Are the 2 iSCSI fabric cross connected in any way (virtual port channels or anything)?

[LaurenMalhoit]

No

[mcowger]

For a VNX, with this config, I'd probably expect to see 4path to a given LU.

Each initiator (sounds like you have 2 iSCSI VMKs) will see 2 targets each (ports on the VNX).

2 * 2 = 4.