Created attachment 510609 [details]
vdsm log

Description of problem:

scenario: 

on connectStorageServer command, iSCSI, VDSM performs discovery command (iscsiadm -m discovery -t st -p <ip>:<port>) for each node, with regardless if portal is the same for all nodes.
this has scalability & performance affect. 

actual affect: connectStorageServer takes 4 minutes with 182 targets (in my case, 2 portals, each portal expose 91 targets:

[root@nott-vds2 ~]# grep "/sbin/iscsiadm -m discoverydb -t sendtargets -p 10.35.64.103:3260 --discover" /tmp/checkSesssion  |wc -l
91

[root@nott-vds2 ~]# grep "/sbin/iscsiadm -m discoverydb -t sendtargets -p 10.35.64.106:3260 --discover" /tmp/checkSesssion  |wc -l 
91


example: 

portal: 10.35.64.103

node: iqn.2011-06.com.redhat:test1
node: iqn.2011-06.com.redhat:test2

login: 

iscsadm -m discovery -t st -p 10.35.64.103:3260

iscsadm -m node -T iqn.2011-06.com.redhat:test1 -l 

iscsadm -m discovery -t st -p 10.35.64.103:3260 

iscsadm -m node -T iqn.2011-06.com.redhat:test2 -l 

VDSM should take into account portal address, and in case all nodes resides within 1 portal, skip discovery command