e2image.c, e2image.8.in: Add support for the -s option which

scrambles directory entries for raw image files.

1 files changed, 49 insertions, 29 deletions

diff --git a/misc/e2image.8.in b/misc/e2image.8.in
index 45ee272d..4b75e6df 100644
--- a/misc/e2image.8.in
+++ b/misc/e2image.8.in
@@ -8,7 +8,7 @@ e2image \- Save critical ext2/ext3 filesystem data to a file
 .SH SYNOPSIS
 .B e2image
 [
-.B \-rI
+.B \-rsI
 ]
 .I device
 .I image-file
@@ -45,10 +45,41 @@ requires random-access access to the file, which can not be done using a
 pipe.  This restriction will hopefully be lifted in a future version of
 .BR e2image .)
 .PP
+It is a very good idea to periodically (at boot time and 
+every week or so) to create image files for all of
+filesystems on a system, as well as saving the partition
+layout (which can be generated using the using
+.B fdisk \-l
+command).  Ideally the image file should be stored on some filesystem
+other that
+the filesystem whose data it contains, to ensure that its data is
+accessible in the case where the filesystem has been badly damaged.
+.PP
+To save disk space, 
+.B e2image
+creates the image file as a sparse file.  
+Hence, if the image file
+needs to be copied to another location, it should
+either be compressed first or copied using the 
+.B \-\-sparse=always
+option to GNU version of 
+.BR cp .  
+.PP
+The size of an ext2 image file depends primarily on the size of the
+filesystems and how many inodes are in use.  For a typical 10 gigabyte
+filesystem, with 200,000 inodes in use out of 1.2 million inodes, the
+image file be approximately 35 megabytes; a 4 gigabyte filesystem with
+15,000 inodes in use out of 550,000 inodes will result in a 3 megabyte
+image file.  Image files tend to be quite
+compressible; an image file taking up 32 megabytes of space on
+disk will generally compress down to 3 or 4 megabytes.
+.PP
+.SH RESTORING FILESYSTEM METADATA USING AN IMAGE FILE
+.PP
 The 
 .B \-I 
 option will cause e2image to install the metadata stored in the image
-file to the device.    It can be used to restore the filesystem metadata
+file back to the device.    It can be used to restore the filesystem metadata
 back to the device in emergency situations.
 .PP
 .B WARNING!!!!
@@ -62,6 +93,7 @@ be lost.  In general, you should make a full image
 backup of the filesystem first, in case you wish to try other recovery
 strategies afterwards.
 .PP
+.SH RAW IMAGE FILES
 The 
 .B \-r
 option will create a raw image file instead of a normal image file.  
@@ -74,37 +106,25 @@ created as a sparse file.  (Beware of copying or
 compressing/decompressing this file with utilities that don't understand
 how to create sparse files; the file will become as large as the
 filesystem itself!)  Secondly, the raw image file also includes indirect
-blocks and data blocks, which the current image file does not have,
+blocks and directory blocks, which the standard image file does not have,
 although this may change in the future.
 .PP
-It is a very good idea to periodically (at boot time and 
-every week or so) to create image files for all of
-filesystems on a system, as well as saving the partition
-layout (which can be generated using the using
-.B fdisk \-l
-command).  Ideally the image file should be stored on some filesystem
-other that
-the filesystem whose data it contains, to ensure that its data is
-accessible in the case where the filesystem has been badly damaged.
+Raw image files are sometimes used when sending filesystems to as part
+of bug reports to e2fsprogs.  When used in this capacity, the
+recommended command is (replace hda1 with appropriate device):
 .PP
-To save disk space, 
-.B e2image
-creates the image file as a sparse file.  
-Hence, if the image file
-needs to be copied to another location, it should
-either be compressed first or copied using the 
-.B \-\-sparse=always
-option to GNU version of 
-.BR cp .  
+.br
+\	\fBe2image -r /dev/hda1 - | bzip2 > hda1.e2i.bz2\fR
 .PP
-The size of an ext2 image file depends primarily on the size of the
-filesystems and how many inodes are in use.  For a typical 10 gigabyte
-filesystem, with 200,000 inodes in use out of 1.2 million inodes, the
-image file be approximately 35 megabytes; a 4 gigabyte filesystem with
-15,000 inodes in use out of 550,000 inodes will result in a 3 megabyte
-image file.  Image files tend to be quite
-compressible; an image file taking up 32 megabytes of space on
-disk will generally compress down to 3 or 4 megabytes.
+This will only send the metadata information, without any data blocks.  
+However, the filenames in the directory blocks can still reveal
+information about the contents of the filesystem that the bug reporter
+may wish to keep confidential.  To address this concern, the
+.B \-s
+option can be specified.  This will cause
+.B e2image 
+to scramble directory entries and zero out any unused portions
+of the directory blocks before writing them to the image file.
 .PP
 .SH AUTHOR
 .B e2image