Updating Cached File Systems With Back File Systems

With the AutoClient technology, a new cache consistency mode has been added to the CacheFS consistency model. This consistency mode is called demandconst, which is a new option to the cfsadmin(1M) command. This mode assumes that files are generally not changed on the server, and that if they ever are changed, the system administrator will explicitly request a consistency check. So no consistency checking is performed unless a check is requested. There is an implied consistency check when a CacheFS file system is mounted (when the AutoClient system boots), and an AutoClient system is configured by default to request a consistency check every 24 hours. This model helps AutoClient performance by imposing less network load by performing less checking.

The risk of inconsistent data is minimal since the system's root area is exported only to that system. There is no cache inconsistency when the system modifies its own data since modifications are made through the cache. The only other way a system's root data can be modified is by root on the server.

The /usr file system is similar in that the server exports it as read-only, so the only way it could be modified is by the system administrator on the server. Use the autosync(1m) command to synchronize a system's cached file system with its corresponding back file systems.

You can update individual AutoClient systems, all local AutoClient systems in your network, or all AutoClient systems in a designated file, to match their corresponding back file systems. You should do this update when you add a new package in the shared /usr directory or in one or more system / (root) directories, or when you add a patch. The following procedures show how to use the autosync(1M) command. The command is issued from the server.

Requirements for Using the autosync Command

To use the autosync command, you need to be a member of the UNIX group, sysadmin (group 14).

If you need to create the sysadmin group, see "Setting Up User Permissions to Use the Solstice AutoClient Software".

How to Update All AutoClient Systems With Their Back File Systems

Use the autosync command with no options to update all cached file systems on all the AutoClient systems in your network that are local to the server you are running the autosync command on.

% autosync

The system responds with the names of any systems that failed to be updated. No system response means the updates were all successful.

Example of Updating All AutoClient Systems With Their Back File Systems

The following example shows an update that failed on systems pluto, genesis, and saturn.

% autosync
pluto:: failed:
genesis:: failed:
saturn:: failed:

Verification

If there is no system response, all updates are successful.

How to Update a Single AutoClient System With Its Back File System

Use the autosync command with the -h option to update all cached file systems on a specified AutoClient system in your network:

% autosync -h  hostname

In this command,

Example of Updating One AutoClient System With its Back File System

The following example shows how to update all cached file systems on the AutoClient system pluto:

If the system failed to be updated, you would get the following system response:

Verification

If there is no system response, all updates are successful.

How to Update a Specific File System on an AutoClient System

Use the autosync command as follows to synchronize a specific file system on an AutoClient system with its back file system:

% autosync -h  hostname  cached-filesystem

In this command,

Example of Updating a Specific File System on an AutoClient System

The following example shows how to update the cached file system /usr on the AutoClient system foo:

How to Update More Than One AutoClient System With Its Back File System

1. Create a file containing the names of the systems you want to synchronize with their back file systems.

   The file can be located anywhere. For example, you could put the file in /tmp or /home. If you run the autosync command without arguments and several systems fail to update, put the names of the systems that failed to update in this file. For example, enter one name per line.

2. Use the autosync command as follows to update all AutoClient systems in the host_file file.

   % autosync -H host_file

   In this command,

   -H	Specifies a file containing the names of all AutoClient systems to update.
   host_file	Is the name of the file containing the names of all AutoClient systems in the network you want to update.

Example of Updating More Than One AutoClient System Using a File

The following example shows how to update all AutoClient systems in the host file net_hosts:

For example, the contents of net_hosts might be:

mars jupiter saturn

How to Update an AutoClient System From the System Itself

Use the autosync command as follows to update all cached file systems on a AutoClient system. This command is used on the system itself, and not the server:

% autosync -l 

You can also specify a particular file system on the system that requires updating.

Example of Updating an AutoClient System From the System Itself

The following example shows how a client requests update of its own /usr file system: