1. Use telent, SSH connecting to the SAN IP (no group IP) or null modem cable connecting to the SAN serial port. 2. login using grpadmin account. 3. run shutdown command.
Here are example.
PS Series Storage Arrays Unauthorized Access Prohibited
login: grpadmin Password:
Welcome to Group Manager
Copyright 2001-2008 EqualLogic, Inc.
SANGP> shutdown Do you really want to shutdown the system? (yes/no) [no]yes Halt at Tue Jun 9 18:37:04 CDT 2009 -- please wait... 5823:0:logevent: 9-Jun-2009 18:37:04.280835:logevent.c:242:WARNING:25.3.0:User has initiated restart with '(halt)'.
The array has been halted. You can safely power off the array or type any key to restart the array.