Procedure 7.1. Preparing NFS Storage

1. Install nfs-utils

   NFS functionality is provided by the nfs-utils package. Before file shares can be created, check that the package is installed by querying the RPM database for the system:

   $ rpm -qi nfs-utils

   If the nfs-utils package is installed then the package information will be displayed. If no output is displayed then the package is not currently installed. Install it using yum while logged in as the root user:

   # yum install nfs-utils

2. Configure Boot Scripts

   To ensure that NFS shares are always available when the system is operational both the nfs and rpcbind services must start at boot time. Use the chkconfig command while logged in as root to modify the boot scripts.

   # chkconfig --add rpcbind
   # chkconfig --add nfs
   # chkconfig rpcbind on
   # chkconfig nfs on

   Once the boot script configuration has been done, start the services for the first time.

   # service rpcbind start
   # service nfs start

3. Create Directory

   Create the directory you wish to share using NFS.

   # mkdir /exports/iso

   Replace /exports/iso with the name, and path of the directory you wish to use.

4. Export Directory

   To be accessible over the network using NFS the directory must be exported. NFS exports are controlled using the /etc/exports configuration file. Each export path appears on a separate line followed by a tab character and any additional NFS options. Exports to be attached to the Red Hat Enterprise Virtualization Manager must have the read, and write, options set.
   To grant read, and write access to /exports/iso using NFS for example you add the following line to the /etc/exports file.

   /exports/iso       *(rw)

   Again, replace /exports/iso with the name, and path of the directory you wish to use.

5. Reload NFS Configuration

   For the changes to the /etc/exports file to take effect the service must be told to reload the configuration. To force the service to reload the configuration run the following command as root:

   # service nfs reload

6. Set Permissions

   The NFS export directory must be configured for read write access and must be owned by vdsm:kvm. If these users do not exist on your external NFS server use the following command, assuming that /exports/iso is the directory to be used as an NFS share.

   # chown -R 36:36 /exports/iso

   The permissions on the directory must be set to allow read and write access to both the owner and the group. The owner should also have execute access to the directory. The permissions are set using the chmod command. The following command arguments set the required permissions on the /exports/iso directory.

   # chmod 0755 /exports/iso