+ The <option>--file-storage-dir</option> specifies the relative path
+ under the cluster-wide file storage directory to store file-based
+ disks. It is useful for having different subdirectories for
+ different instances. The full path of the directory where the disk
+ files are stored will consist of cluster-wide file storage directory
+ + optional subdirectory + instance name. Example:
+ /srv/ganeti/file-storage/mysubdir/instance1.example.com. This option
+ is only relevant for instances using the file storage backend.
+ </para>
+
+ <para>
+ The <option>--file-driver</option> specifies the driver to use for
+ file-based disks. Note that currently these drivers work with the
+ xen hypervisor only. This option is only relevant for instances using
+ the file storage backend. The available choices are:
+ <variablelist>
+ <varlistentry>
+ <term>loop</term>
+ <listitem>
+ <para>Kernel loopback driver.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>blktap</term>
+ <listitem>
+ <para>blktap driver.</para>
+ </listitem>
+ </varlistentry>
+ <variablelist>
+ </para>
+
+ <para>
+ The loop driver uses loopback devices to access the filesystem
+ within the file. However, running I/O intensive applications
+ in your instance using the loop driver might result in slowdowns.
+ Furthermore, if you use the loopback driver consider increasing
+ the maximum amount of loopback devices (on most systems it's 8)
+ using the max_loop param.
+ </para>
+
+ <para>
+ In order to be able to use the blktap driver you should check
+ if the 'blktapctrl' user space disk agent is running (usually
+ automatically started via xend). This user-level disk I/O
+ interface has the advantage of better performance. Especially
+ if you use a network file system (e.g. NFS) to store your instances
+ this is the recommended choice.
+ </para>
+
+ <para>