RHEV3.0-Hypervisor to maintenance mode shutdown's iSCSI sessions

Hi,

We are running RHEV 3.0 managing two  RHEV 6.2 hypervisor using iSCSI data center. When I moved the hypervisor to maintenance mode, all  iSCSI sessions got disconnected and that causes storage domains to lose all the underlying devices.  

So can someone help me why iSCSI sessions are getting dropped when host goes to maintenance mode.

Thanks,

Inbaraj