These hosts back up the functionality of sge_qmaster in case the master host or the master daemon fails. To be a shadow master host, a machine must have the following characteristics:
It must run sge_shadowd.
It must share sge_qmaster status, job information, and queue configuration information that is logged to disk. In particular, the shadow master hosts need read/write root or administration user access to the sge_qmaster spool directory and to the sge-root/cell/common directory.
The sge-root/cell/common/shadow_masters file must contain a line defining the host as a shadow master host.
If no cell name is specified during installation, the value of cell is default.
The shadow master host facility is activated for a host as soon as these conditions are met. You do not need to restart the grid engine system daemons to make a host into a shadow master host.
Windows hosts cannot act as master hosts.