e2fsck, chattr, lsattr,
libext2fs, libe2p).
The e2compr-0.3.x version will not do.
e2compress program for 0.4.x yet. Do not
try to use the 0.3.x version. If you have the 0.3.x version around,
remove it or archive it (so that you don't run it accidentally).
CONFIG_EXPERIMENTAL in your kernel
config in order to use e2compr. (This is in preparation for
integration into standard kernel.)
(If you downloaded 0.4.21 during the short time that it was available here, be sure to upgrade or downgrade.)
E2compr-0.4.38 includes the fix to the truncate problem (previously
seen mainly with samba), as well as the nfsd problem.
e2compr-0.4.38
patch against kernel 2.2.16.
e2compr-0.4.38
patch against kernel 2.2.15.
e2compr-0.4.38
patch against kernel 2.2.14.
e2compr-0.4.38
patch against kernel 2.2.13.
e2compr-0.4.38
patch against kernel 2.2.12.
e2compr-0.4.38
patch against kernel 2.2.11.
e2compr-0.4.38
patch against kernel 2.2.10.
e2compr-0.4.38
patch against kernel 2.2.9. Should also work for 2.2.8.
Note: From now on, all patches will be compressed with bzip2.
e2compr-0.4.30
patch against kernel 2.2.7. Also works for 2.2.6.
e2compr-0.4.30
patch against kernel 2.2.5.
e2compr 0.4.30 is the first e2compr patch to exclude the LZRW algorithm. If you still have files compressed with the lzrw algorithm, see LZRW algorithm.
e2compr-0.4.29 patch against kernel 2.2.3.
e2compr 0.4.29 includes:
KERN_INFO) when you mount
your first ext2 filesystem (i.e. when we allocate space for e2compr
work area). This feature requested by Junichi Saito. Actually, he
suggested it be displayed at boot time or ext2fs module load time
(depending on whether ext2fs is a module or built in) (and sent a
patch to do that). If anyone wants to change when / in what
circumstances this is displayed, go ahead and mail a diff to
the e2compr list or e2compr maintainer.
Note: there are significant changes in kernels 2.3.7, 2.3.8, and it will take a while to produce an updated e2compr patch for them. For the moment, stick with 2.3.6.
e2compr-0.4.34
patch against kernel 2.3.6.
e2compr-0.4.34
patch against kernel 2.3.2.
e2compr-0.4.33
patch against kernel 2.3.1.
e2compr-0.4.28 patch against kernel 2.1.132.
e2compr-0.4.27 patch against kernel 2.1.131. Fixes "unsupported inode size" problem reported by Junichi Saito.
e2compr-0.4.24
patch against kernel 2.1.126. Includes modularization of the
compression algorithms, thanks to Jan Rêkorajski baggins@hunter.mimuw.edu.pl.
I wouldn't place a lot of trust in this version. In particular, there
are some things with SEPARATE_WORK_AREAS that I'd
like to check.
Stick to 0.4.18 if
you're timid.
Obviously you shouldn't compress the gzip.o module with the gzip algorithm, but I'd be interested to know what happens if you compress it with some other compression method that's also a module. If it causes a problem, post a note to the e2compr mailing list.
e2compr-0.4.18 patch against kernel 2.1.125. Includes working LZO support.
e2compr-0.4.15 patch against kernel 2.1.115. Includes fix for `deadlock on core-dump' problem.
e2compr-0.4.12 patch against kernel 2.1.105. Probably suitable for kernels 2.1.101--106.
If you have a 2.1 kernel before 2.1.101, then either upgrade your kernel (preferable) or ask me for a patch against whatever kernel you use. The 0.4.12+ patches include a bug fix not present in earlier versions.
There is little feature difference between the following patches; the differences are due to changes in the rest of the kernel. There are slight changes in 0.4.9.
e2compr-0.4.9 patch against kernel 2.1.103. Suitable for kernels 2.1.101 and up.
e2compr-0.4.7 patch against kernel 2.1.101. Probably useless now -- use the above patch instead.
e2compr-0.4.6 patch against kernel 2.1.98. Probably suitable for kernels up through 2.1.100 (except for arch/ppc/defconfig).
e2compr-0.4.6 patch against kernel 2.1.94. This patch should be suitable for 2.1.93--7.
e2compr-0.4.5 patch against kernel 2.1.89.
e2compr-0.4.4 patch against kernel 2.1.88.
LZRW is an optional extra compression algorithm for e2compr. If you don't already use lzrw3a, then there's no reason to start. LZRW3a is somewhere between lzv1 and gzip2 in amount of compression and speed.
The main reason that it is excluded from the main e2compr patch (from e2compr 0.4.30 and up) is that the lzrw3a compression method is patented in some countries (including the US), which restricts its use -- and correspondingly conflicts with the GNU GPL.
Here's the patch: e2compr-lzrw-patch.bz2. It should apply cleanly to all e2compr patches from 0.4.30 upwards. (I.e. apply the main e2compr patch before this LZRW patch.)
If you want to change all lzrw-compressed data to be compressed with, say, lzv1, then do (as root):
mountdevs=`grep ext2 /etc/mtab |
cut -d' ' -f 1 |
tr '\n' ' '`
for i in ${mountdevs}; do
if dd if=$i bs=1 skip=1224 count=1 |
od |
sed -n '1s,.*\(...\),\1,p' |
grep '^..[2367]$' > /tmp/curr-algs
then
dir=`grep "^$i " /etc/mtab |
cut -d' ' -f 2`
echo "Recompressing all of $dir filesystem..."
if find ${dir} -xdev -attr +cB -printf \
'=\0=\0=\0=\0=\0%p\0=%E\0-m\0%M\0-b\000%B\0%p\0'|
sed s/lzrw3a/lzv1/g |
xargs -0 -r -n 6 chattr
then
echo "Marking lzrw as not in use on ${i}..."
sed 's/2$/0;s/3$/1/;s/6$/4/;s/7$/5/' \
< /tmp/curr-algs \
> /tmp/new-algs
printf '\'`cat /tmp/new-algs` |
dd of=$i bs=1 seek=1224 count=1
echo "Done ${i}."
else
echo "chattr failed under $dir: xargs exited with $?"
fi
else
echo "lzrw not used on $i"
fi
done
That will take some time, as it takes the precaution of
decompressing then recompressing even files that ostensibly don't
use the lzrw algorithm. (If lsattr says
gzip9, the file could still have one or more
lzrw-compressed clusters; the `gzip9' just means that
future writes to that file will be compressed using
gzip9.)
Note that the above script writes directly to the filesystem
(dd), and hasn't been tested... You may prefer
just downloading the LZRW patch.
Note too that an unfortunate side effect of the above script is
that it decompresses all files marked with compression method
none (or defer). I suppose that could be
corrected by being clever with the sed filter
applied to the find -printf output: replace
all pairs of sextuplets (meaning 6 null-separated items) involving
`defer' with three sextuplets where the first is all
`=', the second compresses with gzip9 (or whatever), and the
third sets the compression method back to `defer'.
e2fsck, chattr, etc.) is now on a
separate page.
The e2c-ancil package contains e2ratio,
e2bitmap, and
clear-e2c.
e2ratio is like
du, but also shows how much space would be taken up
if each file weren't compressed. Also shows percentage compression.
e2bitmap shows which parts (clusters) of a file are
compressed and uncompressed.
clear-e2c allows you to remove the e2compr flag from
the superblock of an ext2 filesystem, so that you can mount the
filesystem under non-e2compr kernels. (You should decompress
all files before using this unless you know what you're doing.
See the man page.)
e2c-ancil_0.4.1-1_i386.deb: Debian i386 package (binaries). Linked against glibc2.1.
e2c-ancil_0.4.1.orig.tar.gz: Source (without Debian parts).
e2c-ancil_0.4.1-1.diff.gz: Debian diffs to source.
These three are equivalent:
See also Documentation/filesystems/ext2_compression
and fs/ext2/ChangeLog.e2compr in your kernel tree.