## Setting Up A Shadow Master In Grid Engine

To set up master shadowing in Grid Engine, the following steps must be taken.

1) Create the shadow_masters file
2) Verify correct permissions
3) Start the shadowd daemon(s)

1) Create a shadow_masters file

The file needs to be created in $SGE_ROOT/default/common. This file should contain the name of the primary master host as the first line. Other hosts that are chosen to assume master responsibility should then be listed in the order desired. For example:

>cat shadow_masters
host1
host2
host3

Here, host1 is the primary master host. Should host1 fail, host2 will take over as the master server after a period of approximately 10 minutes. Further, if host2 should then fail, host3 will take over.

2) Verify correct permissions

All master shadow hosts must have read/write permissions to the qmaster spool directory.

3) Start the shadow daemons

The shadow daemon must be started on all shadow master hosts. This is done via the startup script, sge5. As root on each host, run the following:

     $SGE_ROOT/default/common/sge5 -shadowd

After these steps are completed, master shadowing for the Grid Engine cluster is active.