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9 changed files with 848 additions and 21 deletions
1
.gitignore
vendored
Normal file
1
.gitignore
vendored
Normal file
|
|
@ -0,0 +1 @@
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|||
/zerofree-*.tgz
|
||||
21
Makefile
21
Makefile
|
|
@ -1,21 +0,0 @@
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|||
# Makefile for source rpm: zerofree
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# $Id$
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||||
NAME := zerofree
|
||||
SPECFILE = $(firstword $(wildcard *.spec))
|
||||
|
||||
define find-makefile-common
|
||||
for d in common ../common ../../common ; do if [ -f $$d/Makefile.common ] ; then if [ -f $$d/CVS/Root -a -w $$/Makefile.common ] ; then cd $$d ; cvs -Q update ; fi ; echo "$$d/Makefile.common" ; break ; fi ; done
|
||||
endef
|
||||
|
||||
MAKEFILE_COMMON := $(shell $(find-makefile-common))
|
||||
|
||||
ifeq ($(MAKEFILE_COMMON),)
|
||||
# attept a checkout
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||||
define checkout-makefile-common
|
||||
test -f CVS/Root && { cvs -Q -d $$(cat CVS/Root) checkout common && echo "common/Makefile.common" ; } || { echo "ERROR: I can't figure out how to checkout the 'common' module." ; exit -1 ; } >&2
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||||
endef
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||||
|
||||
MAKEFILE_COMMON := $(shell $(checkout-makefile-common))
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endif
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||||
|
||||
include $(MAKEFILE_COMMON)
|
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98
index.html
Normal file
98
index.html
Normal file
|
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@ -0,0 +1,98 @@
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|||
<html>
|
||||
<head>
|
||||
<!--
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||||
Support idiotic mobile browsers that are incapable of rendering
|
||||
straightforward HTML properly
|
||||
-->
|
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<meta name="viewport" content="width=device-width, initial-scale=1">
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<title>Keeping filesystem images sparse</title>
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</head>
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<body>
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<h2>Keeping filesystem images sparse</h2>
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<p>
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Filesystem images in local files can be used by many PC emulators and
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virtual machines
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(<a href="http://user-mode-linux.sourceforge.net/">user-mode Linux</a>,
|
||||
<a href="http://fabrice.bellard.free.fr/qemu/">QEMU</a> and
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||||
<a href="http://wiki.xensource.com/xenwiki/">Xen</a>, to name but three).
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Typically these filesystems are created as sparse files using
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commands like:
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<p>
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<pre>
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dd if=/dev/zero of=fs.image bs=1024 seek=2000000 count=0
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/sbin/mke2fs fs.image
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</pre>
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where the enormous <code>seek</code> value causes <code>dd</code> to move
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forward by 2GB before writing nothing at all. This results in the
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creation of a sparse file which takes disk space only for blocks which are
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actually used:
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<p>
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<pre>
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$ ls -l fs.image
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-rw-rw-r-- 1 rmy rmy 2048001024 Apr 18 19:10 fs.image
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$ du -s fs.image
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31692 fs.image
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</pre>
|
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As the filesystem is used, more and more of the non-existent blocks are
|
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filled with data and the size of the file on disk grows. Sometimes it would
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be nice to be able to reclaim unused blocks from a filesystem image. However,
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deleting files from the image doesn't return the space to the
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underlying filesystem: even free blocks in the image still consume space.
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Reclaiming the space can be achieved in two stages:
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<ul>
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<li>Fill unused blocks with zeroes
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<li>Make the file sparse again
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</ul>
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<p>
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One traditional way to zero unused blocks is to create a file that fills
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all the free space:
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<p>
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<pre>
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dd if=/dev/zero of=junk
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sync
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rm junk
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</pre>
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<p>
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The disadvantage of <code>dd</code> in this context is that it destroys
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any sparseness that exists: free blocks that were originally represented
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as holes in the image file are replaced with actual blocks containing
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zeroes. Also, filling up a live filesystem is probably a bad idea.
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<p>
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As an alternative approach, and as practice in mucking about with ext2
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filesystems, I've written a utility which scans the free blocks in an
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ext2 filesystem and fills any non-zero blocks with zeroes.
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The source, <a href="zerofree-1.1.1.tgz">zerofree-1.1.1.tgz</a>, is
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available for download.
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<p>
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<ul>
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<li>A cautious user would run fsck on the filesytem both before and after
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running zerofree.
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<li>The filesystem to be processed should be unmounted or mounted read-only.
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<li>The utility also works on ext3 or ext4 filesystems.
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<li>Binary packages are available in the standard repositories for Debian and Fedora.
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<li>The <a href="http://www.sysresccd.org/SystemRescueCd_Homepage">SystemRescueCd</a> live distribution includes zerofree.
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<li><a href="http://libguestfs.org/">guestfish</a> can run zerofree on many types of virtual machine filesystems.
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</ul>
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<p>
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However, this is only half the story: the empty free
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blocks still consume space in the underlying filesystem, so something
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must to be done to reclaim that space.
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<p>
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A common suggestion is to use the sparse file handling capabilities
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of the GNU <code>cp</code> command to take a copy of the filesystem image with
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<code>cp --sparse=always</code> (though this does require the original
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and sparse files to exist at the same time, which may be inconvenient).
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<p>
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If your kernel and util-linux are sufficiently modern and you have a supported
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filesystem you can use <code>fallocate -d</code> to 'dig holes' in a file.
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This makes the file sparse in-place, without using extra disk space.
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<p>
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<hr>
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<address>
|
||||
<a href="mailto:rmy@pobox.com">Ron Yorston</a><br>
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18th April 2004 (updated 19th February 2018)<br>
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Some <a href="obsolete.html">obsolete</a> information has been moved to a
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||||
separate page.
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||||
</address>
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</body>
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</html>
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1
sources
1
sources
|
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@ -0,0 +1 @@
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|||
SHA512 (zerofree-1.1.1.tgz) = 2d7ee57a877bff2491c48054338a26d624ae75c238ac2b0568a75de88b6621c16cc1e7d65500879825d14d8ba44a5173587a061459072769c165bee47c3f9f1c
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274
sparsify.c
Normal file
274
sparsify.c
Normal file
|
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@ -0,0 +1,274 @@
|
|||
/*
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* sparsify - a tool to make files on an ext2 filesystem sparse
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*
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||||
* Copyright (C) 2004-2012 R M Yorston
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*
|
||||
* This file may be redistributed under the terms of the GNU General Public
|
||||
* License, version 2.
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||||
*/
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#include <ext2fs/ext2fs.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <string.h>
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#define USAGE "usage: %s [-n] [-v] filesystem filename ...\n"
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/* initially assume pre-ext4 API version */
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#define API 140
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#if defined(BLOCK_FLAG_READ_ONLY)
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#undef API
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#define API 141
|
||||
#endif
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|
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#if defined(EXT2_FLAG_64BITS)
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#undef API
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#define API 142
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#endif
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|
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struct process_data {
|
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unsigned char *buf;
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int verbose;
|
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int dryrun;
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blk_t count;
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blk_t blocks;
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blk_t total_blocks;
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int old_percent;
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||||
};
|
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static int process(ext2_filsys fs, blk_t *blocknr, e2_blkcnt_t blockcnt,
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blk_t ref_block, int ref_offset, void *priv)
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||||
{
|
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struct process_data *p;
|
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errcode_t errcode;
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int i, group;
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int ret = 0;
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p = (struct process_data *)priv;
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p->blocks++;
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if ( blockcnt >= 0 ) {
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errcode = io_channel_read_blk(fs->io, *blocknr, 1, p->buf);
|
||||
if ( errcode ) {
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||||
return BLOCK_ABORT;
|
||||
}
|
||||
|
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for ( i=0; i < fs->blocksize; ++i ) {
|
||||
if ( p->buf[i] ) {
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||||
break;
|
||||
}
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}
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if ( i == fs->blocksize ) {
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p->count++;
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if ( !p->dryrun ) {
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ext2fs_unmark_block_bitmap(fs->block_map, *blocknr);
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group = ext2fs_group_of_blk(fs, *blocknr);
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#if API >= 142
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ext2fs_bg_free_blocks_count_set(fs, group,
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ext2fs_bg_free_blocks_count(fs, group)+1);
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ext2fs_free_blocks_count_add(fs->super, (blk64_t)1);
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#else
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fs->group_desc[group].bg_free_blocks_count++;
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fs->super->s_free_blocks_count++;
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#endif
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#if API >= 141
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ext2fs_group_desc_csum_set(fs, group);
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#endif
|
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*blocknr = 0;
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ret = BLOCK_CHANGED;
|
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}
|
||||
}
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|
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if ( p->verbose ) {
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||||
double percent;
|
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percent = 100.0 * (double)p->blocks/(double)p->total_blocks;
|
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|
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if ( (int)(percent*10) != p->old_percent ) {
|
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fprintf(stderr, "\r%4.1f%%", percent);
|
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p->old_percent = (int)(percent*10);
|
||||
}
|
||||
}
|
||||
}
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|
||||
return ret;
|
||||
}
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int main(int argc, char **argv)
|
||||
{
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int verbose = 0;
|
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int dryrun = 0;
|
||||
errcode_t ret;
|
||||
int flags;
|
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int superblock = 0;
|
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int open_flags = EXT2_FLAG_RW;
|
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int iter_flags = 0;
|
||||
int blocksize = 0;
|
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ext2_filsys fs = NULL;
|
||||
struct ext2_inode inode;
|
||||
ext2_ino_t root, cwd, inum;
|
||||
int i, c;
|
||||
struct process_data pdata;
|
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|
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while ( (c=getopt(argc, argv, "nv")) != -1 ) {
|
||||
switch (c) {
|
||||
case 'n' :
|
||||
dryrun = 1;
|
||||
#if defined(BLOCK_FLAG_READ_ONLY)
|
||||
iter_flags |= BLOCK_FLAG_READ_ONLY;
|
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#endif
|
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break;
|
||||
case 'v' :
|
||||
verbose = 1;
|
||||
break;
|
||||
default :
|
||||
fprintf(stderr, USAGE, argv[0]);
|
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return 1;
|
||||
}
|
||||
}
|
||||
|
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if ( argc < optind+2 ) {
|
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fprintf(stderr, USAGE, argv[0]);
|
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return 1;
|
||||
}
|
||||
|
||||
ret = ext2fs_check_if_mounted(argv[optind], &flags);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to determine filesystem mount state %s\n",
|
||||
argv[0], argv[optind]);
|
||||
return 1;
|
||||
}
|
||||
|
||||
if ( flags & EXT2_MF_MOUNTED ) {
|
||||
fprintf(stderr, "%s: filesystem %s is mounted\n",
|
||||
argv[0], argv[optind]);
|
||||
return 1;
|
||||
}
|
||||
|
||||
ret = ext2fs_open(argv[optind], open_flags, superblock, blocksize,
|
||||
unix_io_manager, &fs);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to open filesystem %s\n",
|
||||
argv[0], argv[optind]);
|
||||
return 1;
|
||||
}
|
||||
|
||||
pdata.buf = (unsigned char *)malloc(fs->blocksize);
|
||||
if ( pdata.buf == NULL ) {
|
||||
fprintf(stderr, "%s: out of memory (surely not?)\n", argv[0]);
|
||||
return 1;
|
||||
}
|
||||
|
||||
ret = ext2fs_read_inode_bitmap(fs);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: error while reading inode bitmap\n", argv[0]);
|
||||
return 1;
|
||||
}
|
||||
|
||||
ret = ext2fs_read_block_bitmap(fs);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: error while reading block bitmap\n", argv[0]);
|
||||
return 1;
|
||||
}
|
||||
|
||||
root = cwd = EXT2_ROOT_INO;
|
||||
|
||||
for ( i=optind+1; i<argc; ++i ) {
|
||||
ret = ext2fs_namei(fs, root, cwd, argv[i], &inum);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to find file %s\n", argv[0], argv[i]);
|
||||
continue;
|
||||
}
|
||||
|
||||
ret = ext2fs_read_inode(fs, inum, &inode);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to open inode %d\n", argv[0], inum);
|
||||
continue;
|
||||
}
|
||||
|
||||
if ( !ext2fs_inode_has_valid_blocks(&inode) ) {
|
||||
fprintf(stderr, "%s: file %s has no valid blocks\n", argv[0],
|
||||
argv[i]);
|
||||
continue;
|
||||
}
|
||||
|
||||
#if defined(EXT4_EXTENTS_FL) && API < 141
|
||||
if ( inode.i_flags & EXT4_EXTENTS_FL ) {
|
||||
fprintf(stderr, "%s: unable to process %s, it uses extents\n",
|
||||
argv[0], argv[i]);
|
||||
continue;
|
||||
}
|
||||
#endif
|
||||
|
||||
#if defined(EXT4_FEATURE_RO_COMPAT_HUGE_FILE) && defined(EXT4_HUGE_FILE_FL)
|
||||
if ( (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
|
||||
&& (inode.i_flags & EXT4_HUGE_FILE_FL) ) {
|
||||
fprintf(stderr, "%s: unable to process %s, it's huge\n",
|
||||
argv[0], argv[i]);
|
||||
continue;
|
||||
}
|
||||
#endif
|
||||
|
||||
if ( verbose ) {
|
||||
printf("processing %s\n", argv[i]);
|
||||
}
|
||||
|
||||
pdata.verbose = verbose;
|
||||
pdata.dryrun = dryrun;
|
||||
pdata.count = pdata.blocks = 0;
|
||||
pdata.total_blocks = inode.i_blocks/(fs->blocksize >> 9);
|
||||
pdata.old_percent = 1000;
|
||||
ret = ext2fs_block_iterate2(fs, inum, iter_flags, NULL,
|
||||
process, &pdata);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to process file %s\n", argv[0],
|
||||
argv[i]);
|
||||
continue;
|
||||
}
|
||||
|
||||
if ( pdata.count && !dryrun ) {
|
||||
ext2fs_mark_bb_dirty(fs);
|
||||
ext2fs_mark_super_dirty(fs);
|
||||
|
||||
ret = ext2fs_read_inode(fs, inum, &inode);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to open inode (%s)\n", argv[0],
|
||||
argv[i]);
|
||||
continue;
|
||||
}
|
||||
|
||||
#if API >= 141
|
||||
ret = ext2fs_iblk_sub_blocks(fs, &inode, (blk64_t)pdata.count);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to update block count (%s)\n",
|
||||
argv[0], argv[i]);
|
||||
continue;
|
||||
}
|
||||
#else
|
||||
inode.i_blocks -= pdata.count * (fs->blocksize >> 9);
|
||||
#endif
|
||||
|
||||
ret = ext2fs_write_inode(fs, inum, &inode);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: failed to write inode (%s)\n",
|
||||
argv[0], argv[i]);
|
||||
continue;
|
||||
}
|
||||
}
|
||||
|
||||
if ( verbose ) {
|
||||
printf("\r%d/%d/%d %s\n", pdata.count, pdata.blocks,
|
||||
pdata.total_blocks, argv[i]);
|
||||
}
|
||||
}
|
||||
|
||||
ret = ext2fs_close(fs);
|
||||
if ( ret ) {
|
||||
fprintf(stderr, "%s: error while closing filesystem\n", argv[0]);
|
||||
return 1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
96
zerofree.8
Normal file
96
zerofree.8
Normal file
|
|
@ -0,0 +1,96 @@
|
|||
.TH "ZEROFREE" "8"
|
||||
.SH "NAME"
|
||||
zerofree \(em zero free blocks from ext2, ext3 and ext4 file-systems
|
||||
.SH "SYNOPSIS"
|
||||
.PP
|
||||
\fBzerofree\fR [\fB-n\fP] [\fB-v\fP] [\fB-f fillval\fP] \fIfilesystem\fR
|
||||
.SH "DESCRIPTION"
|
||||
.PP
|
||||
\fBzerofree\fR finds the unallocated,
|
||||
blocks with non-zero value content in an ext2, ext3 or ext4
|
||||
\fIfilesystem\fR (e.g. /dev/hda1) and
|
||||
fills them with zeroes (or another octet of your choice).
|
||||
|
||||
|
||||
.PP
|
||||
Filling unused areas with zeroes is useful if the device on
|
||||
which this file-system resides is a disk image. In this case,
|
||||
depending on the type of disk image, a secondary utility may be
|
||||
able to reduce the size of the disk image after zerofree has
|
||||
been run.
|
||||
|
||||
.PP
|
||||
Filling unused areas may also be useful with solid-state
|
||||
drives (SSDs). On some SSDs, filling blocks with ones (0xFF)
|
||||
is reported to trigger Flash block erasure by the firmware,
|
||||
possibly giving a write performance increase.
|
||||
|
||||
.PP
|
||||
The usual way to achieve the same result (zeroing the
|
||||
unallocated blocks) is to run \fBdd\fR (1) to
|
||||
create a file full of zeroes that takes up the entire free
|
||||
space on the drive, and then delete this file. This has many
|
||||
disadvantages, which zerofree alleviates:
|
||||
.IP " \(bu" 6
|
||||
it is slow;
|
||||
.IP " \(bu" 6
|
||||
it makes the disk image (temporarily) grow to its maximal
|
||||
extent;
|
||||
.IP " \(bu" 6
|
||||
it (temporarily) uses all free space on the disk, so other
|
||||
concurrent write actions may fail.
|
||||
|
||||
.PP
|
||||
\fIfilesystem\fR has to be unmounted or
|
||||
mounted read-only for \fBzerofree\fR to work. It
|
||||
will exit with an error message if the
|
||||
\fIfilesystem\fR is mounted writable. To
|
||||
remount the root file-system readonly, you can first switch to
|
||||
single user runlevel (\fBtelinit 1\fR) then use
|
||||
\fBmount \-o remount,ro
|
||||
\fIfilesystem\fR\fR.
|
||||
|
||||
.PP
|
||||
\fBzerofree\fR has been written to be run
|
||||
from GNU/Linux systems installed as guest OSes inside a virtual
|
||||
machine. In this case, it is typically run from within the guest
|
||||
system, and a utility is then run from the host system to shrink
|
||||
disk image (\fBVBoxManage modifyhd \-\-compact\fR,
|
||||
provided with virtualbox, is able to do that for some disk image
|
||||
formats).
|
||||
|
||||
.PP
|
||||
It may however be useful in other situations: for instance
|
||||
it can be used to make it more difficult to retrieve deleted
|
||||
data. Beware that securely deleting sensitive data is not in
|
||||
general an easy task and usually requires writing several times
|
||||
on the deleted blocks.
|
||||
|
||||
.SH "OPTIONS"
|
||||
.IP "\fB-n\fP " 10
|
||||
Perform a dry run (do not modify the file-system);
|
||||
.IP "\fB-v\fP " 10
|
||||
Be verbose: show the number of blocks modified by
|
||||
\fBzerofree\fR (or that would be modified,
|
||||
in case the \fB-n\fP is used), the number of free
|
||||
blocks and the total number of blocks on the
|
||||
filesystem;
|
||||
.IP "\fB-f value\fP " 10
|
||||
Specify the octet value to fill empty blocks with (defaults to
|
||||
0). Argument must be within the range 0 to 255.
|
||||
.SH "SEE ALSO"
|
||||
.PP
|
||||
dd (1).
|
||||
.SH "AUTHOR"
|
||||
.PP
|
||||
This manual page was written by Thibaut Paumard <paumard@users.sourceforge.net> for
|
||||
the \fBDebian\fP system (but may be used by others). Permission is
|
||||
granted to copy, distribute and/or modify this document under
|
||||
the terms of the GNU General Public License, Version 2 or any
|
||||
later version published by the Free Software Foundation.
|
||||
|
||||
.PP
|
||||
On Debian systems, the complete text of the GNU General Public
|
||||
License can be found in /usr/share/common-licenses/GPL-2.
|
||||
|
||||
.\" created by instant / docbook-to-man, Thu 31 Dec 2020, 01:06
|
||||
193
zerofree.sgml
Normal file
193
zerofree.sgml
Normal file
|
|
@ -0,0 +1,193 @@
|
|||
<!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN" [
|
||||
|
||||
<!-- Process this file with docbook-to-man to generate an nroff manual
|
||||
page: `docbook-to-man manpage.sgml > manpage.1'. You may view
|
||||
the manual page with: `docbook-to-man manpage.sgml | nroff -man |
|
||||
less'.
|
||||
-->
|
||||
|
||||
<!ENTITY dhfirstname "<firstname>Thibaut</firstname>">
|
||||
<!ENTITY dhsurname "<surname>Paumard</surname>">
|
||||
<!-- Please adjust the date whenever revising the manpage. -->
|
||||
<!ENTITY dhdate "<date>April 3rd, 2012</date>">
|
||||
<!ENTITY dhsection "<manvolnum>8</manvolnum>">
|
||||
<!ENTITY dhemail "<email><paumard@users.sourceforge.net></email>">
|
||||
<!ENTITY dhusername "Thibaut Paumard">
|
||||
<!ENTITY dhucpackage "<refentrytitle>ZEROFREE</refentrytitle>">
|
||||
<!ENTITY dhpackage "zerofree">
|
||||
|
||||
<!ENTITY debian "<productname>Debian</productname>">
|
||||
<!ENTITY gnu "<acronym>GNU</acronym>">
|
||||
<!ENTITY gpl "&gnu; <acronym>GPL</acronym>">
|
||||
]>
|
||||
|
||||
<refentry>
|
||||
<refentryinfo>
|
||||
<address>
|
||||
&dhemail;
|
||||
</address>
|
||||
<author>
|
||||
&dhfirstname;
|
||||
&dhsurname;
|
||||
</author>
|
||||
<copyright>
|
||||
<year>2003</year>
|
||||
<holder>&dhusername;</holder>
|
||||
</copyright>
|
||||
&dhdate;
|
||||
</refentryinfo>
|
||||
<refmeta>
|
||||
&dhucpackage;
|
||||
|
||||
&dhsection;
|
||||
</refmeta>
|
||||
<refnamediv>
|
||||
<refname>&dhpackage;</refname>
|
||||
|
||||
<refpurpose>zero free blocks from ext2, ext3 and ext4 file-systems</refpurpose>
|
||||
</refnamediv>
|
||||
<refsynopsisdiv>
|
||||
<cmdsynopsis>
|
||||
<command>&dhpackage;</command>
|
||||
|
||||
<arg><option>-n</option></arg>
|
||||
|
||||
<arg><option>-v</option></arg>
|
||||
|
||||
<arg><option>-f fillval</option></arg>
|
||||
|
||||
<arg choice=req><replaceable>filesystem</replaceable></arg>
|
||||
</cmdsynopsis>
|
||||
</refsynopsisdiv>
|
||||
<refsect1>
|
||||
<title>DESCRIPTION</title>
|
||||
|
||||
<para><command>&dhpackage;</command> finds the unallocated,
|
||||
blocks with non-zero value content in an ext2, ext3 or ext4
|
||||
<replaceable>filesystem</replaceable> (e.g. /dev/hda1) and
|
||||
fills them with zeroes (or another octet of your choice).
|
||||
|
||||
<para>Filling unused areas with zeroes is useful if the device on
|
||||
which this file-system resides is a disk image. In this case,
|
||||
depending on the type of disk image, a secondary utility may be
|
||||
able to reduce the size of the disk image after zerofree has
|
||||
been run.</para>
|
||||
|
||||
<para>Filling unused areas may also be useful with solid-state
|
||||
drives (SSDs). On some SSDs, filling blocks with ones (0xFF)
|
||||
is reported to trigger Flash block erasure by the firmware,
|
||||
possibly giving a write performance increase.</para>
|
||||
|
||||
<para>The usual way to achieve the same result (zeroing the
|
||||
unallocated blocks) is to run <command>dd</command> (1) to
|
||||
create a file full of zeroes that takes up the entire free
|
||||
space on the drive, and then delete this file. This has many
|
||||
disadvantages, which zerofree alleviates:</para>
|
||||
<itemizedlist>
|
||||
<listitem><para>it is slow;</para></listitem>
|
||||
|
||||
<listitem><para>it makes the disk image (temporarily) grow to its maximal
|
||||
extent;</para></listitem>
|
||||
|
||||
<listitem><para>it (temporarily) uses all free space on the disk, so other
|
||||
concurrent write actions may fail.</para></listitem>
|
||||
|
||||
</itemizedlist>
|
||||
|
||||
<para><replaceable>filesystem</replaceable> has to be unmounted or
|
||||
mounted read-only for <command>&dhpackage;</command> to work. It
|
||||
will exit with an error message if the
|
||||
<replaceable>filesystem</replaceable> is mounted writable. To
|
||||
remount the root file-system readonly, you can first switch to
|
||||
single user runlevel (<command>telinit 1</command>) then use
|
||||
<command>mount -o remount,ro
|
||||
<replaceable>filesystem</replaceable></command>.</para>
|
||||
|
||||
<para><command>&dhpackage;</command> has been written to be run
|
||||
from GNU/Linux systems installed as guest OSes inside a virtual
|
||||
machine. In this case, it is typically run from within the guest
|
||||
system, and a utility is then run from the host system to shrink
|
||||
disk image (<command>VBoxManage modifyhd --compact</command>,
|
||||
provided with virtualbox, is able to do that for some disk image
|
||||
formats).</para>
|
||||
|
||||
<para>It may however be useful in other situations: for instance
|
||||
it can be used to make it more difficult to retrieve deleted
|
||||
data. Beware that securely deleting sensitive data is not in
|
||||
general an easy task and usually requires writing several times
|
||||
on the deleted blocks.</para>
|
||||
|
||||
</refsect1>
|
||||
<refsect1>
|
||||
<title>OPTIONS</title>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
<term><option>-n</option>
|
||||
</term>
|
||||
<listitem>
|
||||
<para>Perform a dry run (do not modify the file-system);</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term><option>-v</option>
|
||||
</term>
|
||||
<listitem>
|
||||
<para>Be verbose: show the number of blocks modified by
|
||||
<command>&dhpackage;</command> (or that would be modified,
|
||||
in case the <option>-n</option> is used), the number of free
|
||||
blocks and the total number of blocks on the
|
||||
filesystem;</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term><option>-f value</option>
|
||||
</term>
|
||||
<listitem>
|
||||
<para>Specify the octet value to fill empty blocks with (defaults to
|
||||
0). Argument must be within the range 0 to 255.</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
</refsect1>
|
||||
<refsect1>
|
||||
<title>SEE ALSO</title>
|
||||
|
||||
<para>dd (1).</para>
|
||||
|
||||
</refsect1>
|
||||
<refsect1>
|
||||
<title>AUTHOR</title>
|
||||
|
||||
<para>This manual page was written by &dhusername; &dhemail; for
|
||||
the &debian; system (but may be used by others). Permission is
|
||||
granted to copy, distribute and/or modify this document under
|
||||
the terms of the &gnu; General Public License, Version 2 or any
|
||||
later version published by the Free Software Foundation.
|
||||
</para>
|
||||
<para>
|
||||
On Debian systems, the complete text of the GNU General Public
|
||||
License can be found in /usr/share/common-licenses/GPL-2.
|
||||
</para>
|
||||
|
||||
</refsect1>
|
||||
</refentry>
|
||||
|
||||
<!-- Keep this comment at the end of the file
|
||||
Local variables:
|
||||
mode: sgml
|
||||
sgml-omittag:t
|
||||
sgml-shorttag:t
|
||||
sgml-minimize-attributes:nil
|
||||
sgml-always-quote-attributes:t
|
||||
sgml-indent-step:2
|
||||
sgml-indent-data:t
|
||||
sgml-parent-document:nil
|
||||
sgml-default-dtd-file:nil
|
||||
sgml-exposed-tags:nil
|
||||
sgml-local-catalogs:nil
|
||||
sgml-local-ecat-files:nil
|
||||
End:
|
||||
-->
|
||||
|
||||
|
||||
185
zerofree.spec
Normal file
185
zerofree.spec
Normal file
|
|
@ -0,0 +1,185 @@
|
|||
Summary: Utility to force unused ext2/3/4 inodes and blocks to zero
|
||||
Name: zerofree
|
||||
Version: 1.1.1
|
||||
Release: 18%{?dist}
|
||||
License: GPL-2.0-only
|
||||
URL: https://frippery.org/uml/
|
||||
Source0: https://frippery.org/uml/%{name}-%{version}.tgz
|
||||
Source1: https://frippery.org/uml/sparsify.c
|
||||
Source2: https://frippery.org/uml/index.html
|
||||
# zerofree.sgml is the source for the man page from Debian.
|
||||
# Unfortunately we cannot build this in Fedora because we do not have
|
||||
# docbook-to-man, just docbook2man and db2x_docbook2man. The included
|
||||
# man page was generated on a Debian system from this source.
|
||||
Source3: zerofree.sgml
|
||||
Source4: zerofree.8
|
||||
BuildRequires: gcc
|
||||
BuildRequires: make
|
||||
BuildRequires: e2fsprogs-devel
|
||||
|
||||
%description
|
||||
zerofree is a utility to set unused filesystem inodes and blocks of an
|
||||
ext2/3/4 filesystem to zero. This can improve the compressibility and
|
||||
privacy of an ext2/3/4 filesystem.
|
||||
|
||||
This tool was inspired by the ext2fs privacy (i.e. secure deletion)
|
||||
patch described in a Linux kernel mailing list thread.
|
||||
|
||||
WARNING: The filesystem to be processed should be unmounted or mounted
|
||||
read-only. The tool tries to check this before running, but you
|
||||
should be careful.
|
||||
|
||||
%prep
|
||||
%setup -q
|
||||
cp -p %{SOURCE1} %{SOURCE2} .
|
||||
|
||||
%build
|
||||
make CC="%{__cc} $RPM_OPT_FLAGS $RPM_LD_FLAGS"
|
||||
%{__cc} $RPM_OPT_FLAGS $RPM_LD_FLAGS -o sparsify sparsify.c -lext2fs
|
||||
|
||||
%install
|
||||
install -D -p -m 755 zerofree $RPM_BUILD_ROOT%{_sbindir}/zerofree
|
||||
install -D -p -m 755 sparsify $RPM_BUILD_ROOT%{_sbindir}/sparsify
|
||||
install -D -p -m 644 %{SOURCE4} $RPM_BUILD_ROOT%{_mandir}/man8/zerofree.8
|
||||
|
||||
%files
|
||||
%license COPYING
|
||||
%doc index.html
|
||||
%{_sbindir}/zerofree
|
||||
%{_sbindir}/sparsify
|
||||
%{_mandir}/man8/zerofree.8*
|
||||
|
||||
%changelog
|
||||
* Fri Jul 17 2026 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-18
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild
|
||||
|
||||
* Sat Jan 17 2026 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-17
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_44_Mass_Rebuild
|
||||
|
||||
* Fri Jul 25 2025 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-16
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_43_Mass_Rebuild
|
||||
|
||||
* Sun Jan 19 2025 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-15
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild
|
||||
|
||||
* Sat Jul 20 2024 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-14
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_41_Mass_Rebuild
|
||||
|
||||
* Sat Jan 27 2024 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-13
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild
|
||||
|
||||
* Sat Jul 22 2023 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-12
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild
|
||||
|
||||
* Sat Jan 21 2023 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-11
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild
|
||||
|
||||
* Sat Jul 23 2022 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-10
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_37_Mass_Rebuild
|
||||
|
||||
* Sat Jan 22 2022 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-9
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_36_Mass_Rebuild
|
||||
|
||||
* Fri Jul 23 2021 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-8
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_35_Mass_Rebuild
|
||||
|
||||
* Thu Jan 28 2021 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-7
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild
|
||||
|
||||
* Wed Jul 29 2020 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-6
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild
|
||||
|
||||
* Fri Jan 31 2020 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-5
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_32_Mass_Rebuild
|
||||
|
||||
* Sat Jul 27 2019 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-4
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild
|
||||
|
||||
* Sun Feb 03 2019 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-3
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_30_Mass_Rebuild
|
||||
|
||||
* Sat Jul 14 2018 Fedora Release Engineering <releng@fedoraproject.org> - 1.1.1-2
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass_Rebuild
|
||||
|
||||
* Tue Feb 20 2018 Robert Scheck <robert@fedoraproject.org> - 1.1.1-1
|
||||
- Upgrade to 1.1.1
|
||||
|
||||
* Mon Feb 19 2018 Robert Scheck <robert@fedoraproject.org> - 1.1.0-1
|
||||
- Upgrade to 1.1.0
|
||||
|
||||
* Fri Feb 09 2018 Fedora Release Engineering <releng@fedoraproject.org> - 1.0.3-10
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild
|
||||
|
||||
* Thu Aug 03 2017 Fedora Release Engineering <releng@fedoraproject.org> - 1.0.3-9
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_27_Binutils_Mass_Rebuild
|
||||
|
||||
* Thu Jul 27 2017 Fedora Release Engineering <releng@fedoraproject.org> - 1.0.3-8
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_27_Mass_Rebuild
|
||||
|
||||
* Sat Feb 11 2017 Fedora Release Engineering <releng@fedoraproject.org> - 1.0.3-7
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_26_Mass_Rebuild
|
||||
|
||||
* Wed Apr 06 2016 Robert Scheck <robert@fedoraproject.org> - 1.0.3-6
|
||||
- Build with ext4 support for RHEL 5 (#862934, thanks to Mike Swanson)
|
||||
|
||||
* Fri Feb 05 2016 Fedora Release Engineering <releng@fedoraproject.org> - 1.0.3-5
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_24_Mass_Rebuild
|
||||
|
||||
* Fri Jun 19 2015 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.3-4
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_23_Mass_Rebuild
|
||||
|
||||
* Mon Aug 18 2014 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.3-3
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_21_22_Mass_Rebuild
|
||||
|
||||
* Sat Jun 07 2014 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.3-2
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_21_Mass_Rebuild
|
||||
|
||||
* Mon Nov 18 2013 Richard W.M. Jones <rjones@redhat.com> - 1.0.3-1
|
||||
- New upstream version 1.0.3.
|
||||
- New upstream version of sparsify.c.
|
||||
- Fix the license.
|
||||
- Modernize the spec file.
|
||||
- Remove sparsify patch (equivalent patch has gone upstream).
|
||||
|
||||
* Sun Aug 04 2013 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.1-13
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_20_Mass_Rebuild
|
||||
|
||||
* Fri Feb 15 2013 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.1-12
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_19_Mass_Rebuild
|
||||
|
||||
* Sun Jul 22 2012 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.1-11
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_18_Mass_Rebuild
|
||||
|
||||
* Mon Jan 16 2012 Richard W.M. Jones <rjones@redhat.com> - 1.0.1-10
|
||||
- Patch sparsify to work with e2fsprogs >= 1.42.
|
||||
|
||||
* Sat Jan 14 2012 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.1-9
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_17_Mass_Rebuild
|
||||
|
||||
* Tue Feb 08 2011 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.1-8
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_15_Mass_Rebuild
|
||||
|
||||
* Thu May 27 2010 Richard W.M. Jones <rjones@redhat.com> - 1.0.1-7
|
||||
- Include zerofree(8) man page from Debian (RHBZ#596732).
|
||||
|
||||
* Mon Jul 27 2009 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.0.1-6
|
||||
- Rebuilt for https://fedoraproject.org/wiki/Fedora_12_Mass_Rebuild
|
||||
|
||||
* Fri May 15 2009 Richard W.M. Jones <rjones@redhat.com> - 1.0.1-5
|
||||
- Include the index file as a source file.
|
||||
- Improve the description, remove spelling mistakes and other typos.
|
||||
- Use the upstream SRPM directly, unpacking source from it.
|
||||
- Fix use of dist macro.
|
||||
- Pass the RPM OPTFLAGS to C compiler (should also fix debuginfo pkg).
|
||||
- Use 'cp -p' to preserve timestamps when copying index.html file.
|
||||
- Fix the defattr line.
|
||||
- License is GPL+ (any version of the GPL including 1).
|
||||
- Use a simpler install command to install the binary.
|
||||
- Fix the upstream URL to point to the real original project.
|
||||
- Add the sparsify command.
|
||||
|
||||
* Thu May 14 2009 Richard W.M. Jones <rjones@redhat.com> - 1.0.1-1
|
||||
- Initial packaging for Fedora, based on R P Herrold's package.
|
||||
|
||||
* Wed May 13 2009 R P Herrold <info@owlriver.com> - 1.0.1-1
|
||||
- initial packaging
|
||||
Loading…
Add table
Add a link
Reference in a new issue