Penguin
Recent Changes

Differences between version 7 and predecessor to the previous major change of Ext3.

Other diffs: Previous Revision, Previous Author, or view the Annotated Edit History

Newer page: version 7 Last edited on Sunday, November 28, 2004 12:31:20 am by AristotlePagaltzis Revert
Older page: version 3 Last edited on Wednesday, August 11, 2004 10:11:37 am by PerryLorier Revert
@@ -1,16 +1,30 @@
-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''  
+Note that despite journalling, you should periodically fsck(8) [Ext3] FileSystem~s to ensure they are consistent. HardDisk errors f.ex can still introduce problems.  
  
-where the only journal option currently supported is __-J size=xMB__. See tune2fs(8) for min /max size.  
+You can turn [Ext2] FileSystem~s into [Ext3] ones at any time by issuing  
+  
+<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.  
+  
+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>  
  
-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 . 
+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 .