Software ISCSI adapter rescan takes a long time to complete on ESXi 5.5

Worked on this issue recently where, after upgrading to ESXi 5.5, a rescan on a software ISCSI initiator was taking a long time to complete. About 10  minutes.

There were only two LUN’s presented to the software ISCSI initiator
The software ISCSI initiator was configured to discover LUN’s from four targets.

The vmkernel.log and hostd.log did not show any errors or relevant messages for the ISCSI initiator.

The software ISCSI daemon logs into the following file: /var/log/syslog.log

The syslog.log file contained the following messages during the rescan:

2014-03-11T15:08:22Z iscsid: DISCOVERY: transport\_name=bnx2i-180373f76f81 Pending=0 Failed=0  
2014-03-11T15:08:22Z iscsid: DISCOVERY: transport\_name=bnx2i-180373f76f83 Pending=0 Failed=0  
2014-03-11T15:08:22Z iscsid: DISCOVERY: transport\_name=bnx2i-180373f76f83 Pending=0 Failed=0  
2014-03-11T15:08:22Z iscsid: DISCOVERY: transport\_name=bnx2i-180373f76f85 Pending=0 Failed=0  
2014-03-11T15:08:22Z iscsid: DISCOVERY: transport\_name=bnx2i-180373f76f85 Pending=0 Failed=0  
2014-03-11T15:08:23Z iscsid: discovery\_sendtargets::Running discovery on IFACE default(iscsi\_vmk) (drec.transport=iscsi\_vmk)  
2014-03-11T15:08:23Z iscsid: discovery\_sendtargets::Running discovery on IFACE iscsi\_vmk@vmk1(iscsi\_vmk) (drec.transport=iscsi\_vmk)  
2014-03-11T15:08:23Z iscsid: discovery\_sendtargets::Running discovery on IFACE iscsi\_vmk@vmk2(iscsi\_vmk) (drec.transport=iscsi\_vmk)  
2014-03-11T15:08:23Z iscsid: discovery\_sendtargets::Running discovery on IFACE iscsi\_vmk@vmk3(iscsi\_vmk) (drec.transport=iscsi\_vmk)  
2014-03-11T15:09:23Z iscsid: connection failed for discovery (err = Interrupted system call)!  
2014-03-11T15:09:23Z iscsid: connection to discovery address 10.255.250.150 failed  
2014-03-11T15:09:23Z iscsid: connection login retries (reopen\_max) 5 exceeded  
2014-03-11T15:09:23Z iscsid: discovery\_sendtargets::Running discovery on IFACE iscsi\_vmk@vmk4(iscsi\_vmk) (drec.transport=iscsi\_vmk)  

To resolve the long rescan time, we removed the dynamic discovery targets and ensured that only static targets were configured. 

This time, the rescan finished almost immediately. Less than 20 seconds.

To figure out why the discovery is failing on the dynamic targets, we need to look at the storage array.

Update: This was resolved by removing software iscsi port binding