Seeing 4 Paths On One Host and 2 Paths On Another

[vmw9]

I am seeing 4 paths on one host and only 2 paths on another.

This is going to the same Lun.

Setup between 2 hosts is the same.

2 iscsi vnics

2 vmk ips

Each IP is bound to one nic

Any ideas?

[jeberhardt42 · Accepted solution]

Here are a few things to check:

1. On the host that you're only seeing 2 paths, have you verified that both of your vmnics are showing compliant and active on the VMkernel port bindings? I had an issue similar to this and found that one of the nics was showing non-compliant. It came down to the wrong vmnic was selected for the iSCSI vSwitch.

2.Double check to make sure that you have your physical link plugged into your iSCSI VLAN on your switches (if you have them split into their own VLAN)

3. If you're using jumbo frames, do you have the MTU set on the vSwitch and VM port group at 9000?

When you rescan for the additional paths, are you seeing any timeouts in the vmkernel logs? Or is it taking an extended period of time to scan from that host as if it's rescanning multiple times?

[vmw9]

I am confused. I used to see 4 paths to each nimble volume but now only seeing 2 paths. I checked and both iscsi vmks are compliant. I a using the nimble psp.

should it be only showing 2 paths per volume or 4?

I have 2, 10GB nics for iscsi and each vmk is binded to one nic

[rfenton4]

If you have NCM installed you should see 2 by default - these minimises the number of connections that ESX has to manage (as there are a limited of number of connections ESX can utilise)

[vmw9]

Yes I do have ncm installed. If I had 4 iscsi nics and for vmks will that show as 4 paths?

thanks

[rfenton4]

Each nic should see each device down 2 paths

[vmw9]

but I am only seeing 2 paths per volume. Should i be seeing 4? I see some hosts have 4 paths