Hi all,
Does anyone know anything about the "shortest-path" load balancing method when setting up iSCSI multipathing? I see it referenced here https://docs.oracle.com/cd/E53394_01/html/E54792/gqfhh.html:
# mpathadm show mpath-support libmpscsi_vhci.so
Vendor: Sun Microsystems
Driver Name: scsi_vhci
Default Load Balance: round-robin
Supported Load Balance Types:
round-robin
logical-block
shortest-path
...
...but this isn't listed on our (SPARC) systems as a supported load balance type for the libmpscsi_vhci.so library:
# mpathadm show mpath-support libmpscsi_vhci.so
mpath-support: libmpscsi_vhci.so
Vendor: Sun Microsystems
Driver Name: scsi_vhci
Default Load Balance: round-robin
Supported Load Balance Types:
round-robin
logical-block
In fact, I cannot seem to find it documented anywhere. The Oracle page at: https://docs.oracle.com/cd/E53394_01/html/E54792/gqnrd.html only lists the following policies:
- none or same-path
- round-robin
- logical-block
I ask because if 'shortest-path' is true to its name, it would be ideal for our infrastructure setup where we are intending to make multiple path connections to iSCSI storage volumes at different physical sites on a 'campus' network. Under these circumstances it would make sense to have the multipath driver use only the 'shortest' path to the nearest storage, and only use the other one when necessary in a failover situation.
Thank you,
Stuart