EXIT STATUS
On success 0 is returned. On error one of the return codes below will be returned.
Commands  that operation on multiple objects (sessions, records, etc), iscsiadm/iscsistart will return the first error that is encountered.  iscsi-adm/iscsistart will attempt to execute the operation on the objects it can. If no objects are found ISCSI_ERR_NO_OBJS_FOUND is returned.
       0      ISCSI_SUCCESS - command executed successfully.
       1      ISCSI_ERR - generic error code.
       2      ISCSI_ERR_SESS_NOT_FOUND - session could not be found.
       3      ISCSI_ERR_NOMEM - could not allocate resource for operation.
       4      ISCSI_ERR_TRANS - connect problem caused operation to fail.
       5      ISCSI_ERR_LOGIN - generic iSCSI login failure.
       6      ISCSI_ERR_IDBM - error accessing/managing iSCSI DB.
       7      ISCSI_ERR_INVAL - invalid argument.
       8      ISCSI_ERR_TRANS_TIMEOUT - connection timer exired while trying to connect.
       9      ISCSI_ERR_INTERNAL - generic internal iscsid/kernel failure.
       10     ISCSI_ERR_LOGOUT - iSCSI logout failed.
       11     ISCSI_ERR_PDU_TIMEOUT - iSCSI PDU timedout.
       12     ISCSI_ERR_TRANS_NOT_FOUND - iSCSI transport module not loaded in kernel or iscsid.
       13     ISCSI_ERR_ACCESS - did not have proper OS permissions to access iscsid or execute iscsiadm command.
       14     ISCSI_ERR_TRANS_CAPS - transport module did not support operation.
       15     ISCSI_ERR_SESS_EXISTS - session is logged in.
       16     ISCSI_ERR_INVALID_MGMT_REQ - invalid IPC MGMT request.
       17     ISCSI_ERR_ISNS_UNAVAILABLE - iSNS service is not supported.
       18     ISCSI_ERR_ISCSID_COMM_ERR - a read/write to iscsid failed.
       19     ISCSI_ERR_FATAL_LOGIN - fatal iSCSI login error.
       20     ISCSI_ERR_ISCSID_NOTCONN - could ont connect to iscsid.
       21     ISCSI_ERR_NO_OBJS_FOUND - no records/targets/sessions/portals found to execute operation on.
       22     ISCSI_ERR_SYSFS_LOOKUP - could not lookup object in sysfs.
       23     ISCSI_ERR_HOST_NOT_FOUND - could not lookup host.
       24     ISCSI_ERR_LOGIN_AUTH_FAILED - login failed due to authorization failure.
       25     ISCSI_ERR_ISNS_QUERY - iSNS query failure.
       26     ISCSI_ERR_ISNS_REG_FAILED - iSNS registration/deregistration failed.