07-22-2010 11:19 AM
I'm trying to configure an HP LeftHand on HP-UX 11.31. I configured a NORMAL trunk with 2 NIC's using APA, but this only helps me in case of failover. Is there a way for using more than 1 NIC for multipathing to the same LUN?
Thanks in advance.
07-23-2010 08:50 AM
The inbound path is controlled by the packet scheduling algorithm being used by the switch.
So, to get more than one NIC used to a LUN, that LUN needs to be reachable via either more than one MAC address, or more than one IP address, or more than one TCP connection. Then APA will spread the write traffic across multiple NICs in the aggregate. For read traffic (aka inbound from the perspective of the host) it will depend entirely on the switch.
07-23-2010 10:10 AM
HP-UX currently only supports the Software-based iSCSI Initiator. I don't know enough about how iSCSI works to know if it's possible to configure multiple TCP connections to a single iSCSI target, but looking at the iSCSI manual it states:
Connections per Session
The iSCSI Software Initiator supports one connection per session (an iSCSI session is equivalent to a SCSI I-T nexus).
Again, I don't know if by "one connection per session" that equates to "one TCP connection" or not, but I couldn't find anything iron clad in the documentation that shows how to control the number of TCP connections opened between the initiator and target.
Putting on my dusty old NFS hat, HP-UX *does* allow the ability to open multiple TCP connections between an HP-UX NFS client and an NFS server, thus allowing NFS to take advantage of multiple adapters in an APA aggregate.
Food for thought...
02-07-2013 09:07 AM
"I believe the current HP-UX iSCSI software initiator supports only one TCP connection per iSCSI session, so there is no LUN multipathing support."
So just looking for an update on this post, is this restriction still true in 2013 Feb? TIA.