Differences between version 6 and predecessor to the previous major change of Ext3.
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| Newer page: | version 6 | Last edited on Wednesday, August 11, 2004 2:30:28 pm | by PerryLorier | Revert |
| Older page: | version 3 | Last edited on Wednesday, August 11, 2004 10:11:37 am | by PerryLorier | Revert |
@@ -1,16 +1,28 @@
-Ext3 is an extension
of the [Ext2] filesystem, currently adding journalling support
.
+[
Ext3]
is a journaled FileSystem based on [Ext2]. It also has some additional features such as extents (which reduce the amount
of overhead with storing where a file is stored on
the disk for large files), and hash based lookups on directories solving the problem
[Ext2] has with large directories being very slow
.
-To
turn your
[Ext2] file systems
into Ext3 file systems run the command:
- tune2fs -j /dev/''partition''
-or
- tune2fs -j -J ''
[[options
]'' /dev/''partition''
+You can
turn [Ext2] [FileSystem]s
into [Ext3
] ones at any time by issuing
-where the only journal option currently supported is __-J size=xMB__. See
tune2fs(8) for min
/max size.
+<pre>
+
tune2fs -j /dev/''partition''
+<
/pre>
Note that unlike most disk tool commands, you add the journal to a currently mounted partition.
-Also remember
to change fstab(5) to mount the partition as Ext3, and then
-unmount
/remount it or reboot
. (You do not have to do this immediately
).
-You can always mount an ext3 partition as type ext2 -- you just will not have any journalling performed
.
+You can also add <tt>-J</tt>
to pass journal options. The only one currently supported is <tt>size=xMB<
/tt>
. See tune2fs
(8
) for min/max size
.
-Ext3 is also gaining some features such as Extents
(which reduces
the amount of overhead with storing where
a file is stored on
the disk for large files
), and hash based
lookups on Directories solving
the problem
ext2 has with large
directories being very slow
.
+Given [Kernel] support
(eg <tt>CONFIG_EXT3_FS_POSIX_ACL</tt> in a 2.6.x [Kernel]), you can use [POSIX] [ACL]s by either adding <tt>acl</tt> to
the mount options column in fstab(5) or setting
a default mount option in
the partition itself by issuing
+
+<pre>
+tune2fs -o acl /dev/''partition''
+</pre>
+
+Remember to change fstab(5
) to mount the partition as [Ext3]
, and then unmount/remount it or reboot. (You do not have to do this immediately). You can always mount an [Ext3] partition as type [Ext2] -- you just will not have any journalling performed.
+
+You can also enabled hashed directories with a 2.6 kernel. This speeds up
lookups for directories that contain a large numbers of files/directories.
+
+<pre>
+tune2fs -o dir_index /dev/''partition''
+fsck.ext3 -D /dev/''partition''
+</pre>
+
+The fsck is required to move
the existing directories to the new format. If you ever remount the filesystem as
ext2,
directories that are written to will be converted back to the old format, so you need rerun the fsck
.
