-\fBfusefile\fR is FUSE file mount that presents a series of fragments
-of other files as a contiguous concatenation. It bind mounts a driver
-on top of the file mountpoint to present the nominated file fragments
-as a single, contiguous file. It accepts over-writing on the fused
-file which gets distributed accordingly to the fragments, but cannot
-change size.
-
-An optional overlay file is declared with an
-\fB-overlay:\fIfilename\fR argument between the mount point and the
-fragments. This file is then set up as an overlay for capturing writes
-to the fused file. The overlay file will contain the written fused
-file regions, followed by meta data to distinguish between written
-content and "holes" (where content comes from the fused fragments).
+\fBfusefile\fR is a FUSE file mount that presents a series of
+fragments of other files as a contiguous concatenation. It bind mounts
+a driver on top of the file mountpoint to present the nominated file
+fragments as a single, contiguous file. \fBfusefile\fR accepts
+over-writing on the fused file (i.e. the mountpoint) which gets
+distributed accordingly to the fragments, but it cannot change size;
+any writing thus merely replaces content without truncating fragments.
+All fragment files are held open while \fBfusefile\fR is active.
+
+\fBfusedisk\fR is a helper script to set up a \fBfusefile\fR as a
+block device (via \fIfuseblk\fR) by using the device mapper
+(\fBdmsetup\fR) to manage an empty block device mapping where content
+is handled at the mountpoint via \fBfusefile\fR. (Note that the same
+thing may be done with the device manager directly, but then all
+fragments need to be in sectors of N*512 bytes. With \fBfusedisk\fR
+only the fused file as a whole is "clipped" at N*512 bytes)
+
+By using the optional \fB-overlay:\fIfilename\fR argument between the
+mount point and the fragments, an overlay file may be set up. The
+overlay file will then be used by \fBfusefile\fR for capturing writes
+to the fused file (i.e. the mountpoint). The overlay file will contain
+any new written fused file regions followed by meta data to
+distinguish between new, written content and old content that comes
+from the fragments.
+
+.SH FRAGMENT ARGUMENTS