MPIO and multiple connections for bandwidth

Hello, 

 

We have 4 Hosts (2012R2) and 1 EQL (PS6500) set up like this (we actually have 2 EQL's but i will try to keep the info below relevant)

 

Host 1 (2 x 10GB dedicated to iSCSI)

Host 2 (1 x 10GB dedicated to iSCSI)

Host 3 (2 x 10GB dedicated to iSCSI)

Host 4 (2 x 10GB dedicated to iSCSI)

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EQL has 4 x 1GB NIC's

EQL hosts 2 Volumes

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Group Manager - Members -> Connections shows

16 outbound iSCSI connections (8 connections from each volume) 
Each EQL NIC makes 4 outbound iSCSi connects (16 total)

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if i count up all the Hosts' iSCSI NIC's, i get 7, yet the EQL has made 8 connections from each volume.

Every Host IP has 2 connections to the EQL (one per volume) except HOST2 which has made 4 connections (2 per volume) from its single NIC

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1. Why does the behavior differ for the Host2 connection?

2. Would it be possible to use the 3rd and 4th NIC's of the EQL to make even more connections to HOST2?  Or does it somehow max out at 2 per volume?

3. Would i benefit in performance from doing so?  Because it seems like i am seeing a speed increase when moving files from Host2 to the volume.  It seems faster than i would get from a single 1GB NIC.  It's comparable to our other EQL  which has a 10GB nic.   

I tried to manually add another connection from Host2 to one of the volumes (via iSCSI initiator -> targets -> connect)  and it added , stayed for about 6 seconds, and then disappeared.

 

 

 

 

thanks