Are you doing iscsi root boot or just using iscsi for some date
partition/disk and that is not getting logged into? For the latter what
version of the open-iscsi tools are you using? In iscsid.conf do you see a
node.session.initial_login_retry_max
setting and a
node.conn[0].timeo.login_timeout
?
What are the values?
If the timeout is around 15-30 seconds try increasing
initial_login_retry_max.