the journal introduces a slight overhead, but I think ext3 is slightly more
optimized than ext2 so this compensates(according to redhat reports anyway).
It's easy to convert, just run tune2fs -J <nameofdevice> - (all this does
is add a journal file, you can still mount it as ext2) and replace ext2 with
ext3 in your fstab.
If you want a brand new and improved file system, you might want to try the
Reiserfs, which implements fast journalling, and uses balanced trees to
greatly improve file access time, large directory access, and compacts small
files within the same clusters to save space. It's proven to tie closely
with XFS as fastest filesystem(and XFS only wins out on streaming large
files, which reiserfs is catching up on). It's a totally new filesystem, so
no easy conversion between ext2 and reiserfs though.
: Fri, 26 Oct 2001 09:12:46 +0100
>> >>>>> "Peter" == Peter Flynn <peter at silmaril.ie> writes:
>>> Peter> ext3 is journaling. You need more disk space for it but I
> Peter> read somewhere recently (/.?) that it is much better than
> Peter> ext2.
>>I don't think you need that much more disk space.
>>ext2 and ext3 are identical on disk. You don't even have to run a
>conversion tool to switch between them. The differences are at the
>layer just below vfs where writes and reads are imlemented.
>>Journaling is basically a two phase commit process. In ext2 if the
>system dies during a write, then the filesystem will be left in a bad
>state.
>>In ext3 the write is to th journal. If the system crashes while
>writing to the journal, then the transaction can be aborted atboot up,
>leaving the filesystem error free.
>>The journal is committed to the filesystem periodically, but the
>transaction isn't removed form the journal until it is completed on
>the filesystem. If the system crashes during a journal flush, then
>the recovery process can look at the journal and undo all partially
>committed transactions and start a gain.
>>So ext3 is slightly slower ( some say negligible ), and requires the
>overhead of a journal per partition.
>>I think it's worth it. However, I'm not going to upgrade to it on any
>critical systems for another while yet.
>>--
>hjw
>>>_______________________________________________
>Cork maillist - Cork at linux.ie>http://www.linux.ie/mailman/listinfo/cork
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