y colleague Cormac posted an article about this already, but I figured it was important enough to rehash some of content. As many of you have experienced there was an issue with ESXi 5.0 in iSCSI environments. Booting would take a fair amount of time due to the increase of the amount of retries in the case creating a connection to the array would fail.

This is what the log file would typically look like:

iscsid: cannot make a connection to 192.168.1.20:3260 (101,Network is unreachable)
iscsid: Notice: Reclaimed Channel (H34 T0 C1 oid=3)
iscsid: session login failed with error 4,retryCount=3
iscsid: Login Target Failed: iqn.1984-05.com.dell:powervault.md3000i.6002219000a14a2b00000000495e2886 if=iscsi_vmk@vmk8 addr=192.168.1.20:3260 (TPGT:1 ISID:0xf) err=4
iscsid: Login Failed: iqn.1984-05.com.dell:powervault.md3000i.6002219000a14a2b00000000495e2886 if=iscsi_vmk@vmk8 addr=192.168.1.20:3260 (TPGT:1 ISID:0xf) Reason: 00040000 (Initiator Connection Failure)

This is explained in KB 2007108 which also contains the download link. Make sure to download it and update your environment if you are running iSCSI.

--> Please see the rest on the blog :

http://www.yellow-bricks.com/2011/11/06/resolved-slow-booting-of-esxi-5-0-when-iscsi-is-configured/