Rebooting a Server Machine

Rebooting a Server Machine
	Chapter 3. Administering Server Machines

You can reboot a server machine either by typing the appropriate commands at its console or by issuing the bos exec command on a remote machine. Remote rebooting can be more convenient, because you do not need to leave your present location, but you cannot track the progress of the reboot as you can at the console. Remote rebooting is possible because the server machine's operating system recognizes the BOS Server, which executes the bos exec command, as the local superuser root.

Rebooting server machines is part of routine maintenance in some cells, and some instructions in the AFS documentation include it as a step. It is certainly not intended to be the standard method for recovering from AFS-related problems, however, but only a last resort when the machine is unresponsive and you have tried all other reasonable options.

Rebooting causes a service outage. If the machine stores volumes, they are all inaccessible until the reboot completes and the File Server reattaches them. If the machine is a database server machine, information from the databases can become unavailable during the reelection of the synchronization site for each database server process; the VL Server outage generally has the greatest impact, because the Cache Manager must be able to access the VLDB to fetch AFS data.

By convention, a server machine's AFS initialization file includes the following command to restart the BOS Server after each reboot. It starts the other AFS server processes listed in the local /usr/afs/local/BosConfig file. These instructions assume that the initialization file includes the command.

   /usr/afs/bin/bosserver

To reboot a file server machine from its console

Become the local superuser root on the machine, if you are not already, by issuing the su command.
```
   % su root
   Password: root_password
```
Issue the bos shutdown command to shut down all AFS server processes other than the BOS Server, which terminates safely when you reboot the machine. Include the -localauth flag because you are logged in as the local superuser root but do not necessarily have administrative tokens. For a complete description of the command, see To stop processes temporarily.
```
   # bos shutdown <machine name> -localauth [-wait]
```
Reboot the machine. On many system types, the appropriate command is shutdown, but the appropriate options vary; consult your UNIX administrator's guide.
```
    # shutdown
```

To reboot a file server machine remotely

Verify that you are listed in the /usr/afs/etc/UserList file on the machine you are rebooting. If necessary, issue the bos listusers command, which is fully described in To display the users in the UserList file.
```
   % bos listusers <machine name>
```
Issue the bos shutdown to halt AFS server processes other than the BOS Server, which terminates safely when you turn off the machine. For a complete description of the command, see To stop processes temporarily.
```
   % bos shutdown <machine name>  [-wait]
```
Issue the bos exec command to reboot the machine remotely.
```
   % bos exec <machine name> reboot_command
```
where
machine name
Names the file server machine to reboot.
reboot_command
Is the rebooting command for the machine's operating system. The shutdown command is appropriate on many system types, but consult your operating system documentation.


Managing Server IP Addresses and VLDB Server Entries		Chapter 4. Monitoring and Controlling Server Processes