+For 2.6 kernels the ldiskfs filesystem must be used.
+.TP
+--inode_size <size>
+Specify new inode size for underlying ext3 file system. Must be a power of 2
+between 128 and 4096. The default inode size is selected based on the default
+number of stripes specified for the filesystem.
+.TP
+--group_upcall <pathname>
+The group upcall program to call for resolving a user's secondary groups.
+The default value is NONE, which means that the MDS will use whatever
+supplementary group is passed from the client. The supplied upcall is
+/usr/sbin/l_getgroups, which gets groups from the MDS's /etc/group file
+based on the client-supplied UID.
+.TP
+--mkfsoptions <options>
+Optional argument to mkfs.
+.TP
+--mountfsoptions <options>
+Optional argument to mount fs. Mount options will be passed by this argument. For example, extents are to be enabled by adding ",extents" to the --mountfsoptions option. "errors=remount-ro" and "asyncdel" can also be added to it.