Revise documentation on creating files.

diff --git a/src/guestfs.pod b/src/guestfs.pod
index e3f6cf0..3794023 100644 (file)
--- a/src/guestfs.pod
+++ b/src/guestfs.pod
@@ -258,7 +258,11 @@ L</guestfs_tgz_out>.
 It's often the case that you want to write a file or files to the disk
 image.
 
-For small, single files, use L</guestfs_write>.
+To write a small file with fixed content, use L</guestfs_write>.  To
+create a file of all zeroes, use L</guestfs_truncate_size> (sparse) or
+L</guestfs_fallocate64> (with all disk blocks allocated).  There are a
+variety of other functions for creating test files, for example
+L</guestfs_fill> and L</guestfs_fill_pattern>.
 
 To upload a single file, use L</guestfs_upload>.  This call has no
 limits on file content or size (even files larger than 4 GB).