24.5 Private Storage Resource

With the advent of the CFS, all file systems are available to all cluster members. For normal cluster operations, this is probably what you want. However, what if you have data that you want to restrict to one member?

TruCluster Server supports the notion of privately mounted file systems (also know as partitioned file systems – see Chapter 13, section 13.4)^[3]. A partitioned file system is mounted and accessible by one cluster member.

Why would you want a partitioned file system resource? If you have an application resource that uses data, which you do not want any other cluster member to be able to access, then a partitioned file system may be the solution. If you have application data that is on a UFS file system and you would like the file system to be mounted read-write^[4] as well as have the file system highly available, then create a partitioned file system resource. Alternately you may have an application with which you would like to utilize a memory file system (MFS). In V5.1A, the MFS is supported as a partitioned file system.

What is a partitioned file system resource? It is an application resource that mounts and unmounts one or more file systems.

Implementing a partitioned file system resource is relatively straightforward.

Create an application resource.

In the creation of the application resource, one potential implementation detail to consider is placing the file systems and mount points in the resource profile as illustrated in section 24.4.1.1.
In the "start" entry point, mount the file system.
```
 # mount -o server_only kits#kits /kits 
```
In the "stop" entry point, unmount the file system.
If it's possible that open files might be left on the file system after the application has been stopped, you may need to consider using the fuser(8) command to handle this situation should it occur.

^[3]Partitioned file systems were not supported in V5.0A.

^[4]Read-write UFS support began in TruCluster Server version 5.1A but is restricted to a partitioned file system