Description of problem:
Customer changed SAN IP's and after changed it back to the original. After a node reboot, iscsiadm reports login errors on storage because try to connect on the "new" IPs.

Identified a workaround in the compute node, but need to execute it at each compute node reboot.
1. Run "iscsiadm -m node -L automatic"
2. Restart nova-compute service

Version-Release number of selected component (if applicable):
Openstack 16.2.6

How reproducible:
Always

Steps to Reproduce:
1. Deploy a stack with Pure Storage as backend for volumes.
2. Change target IP's.
3. Turn the IP's to the original.

Actual results:
iSCSI is not connecting to Pure Storage on compute node after reboot.

Expected results:
iSCSI automatically connects to Pure Storage on compute node after reboot.

Additional info:
Considering the workaround proposed in the BZ1702842