On Sun, 6 May 2001 18:24:12 +0800 (PHT) Federico Sevilla III <Federico Sevilla
III <jijo@xxxxxxxxxxxxxxx>> wrote:
> This is potential flame bait, so I hope the worst doesn't happen. There
> are a number of journalling filesystems out there for Linux, and among
> them are XFS, ext3, and ReiserFS. In line with my evaluation of XFS, I'm
> looking for documents that compare these three filesystems (or more
> importantly, XFS vs ext3, and XFS vs ReiserFS).
I have done a comparison for my own purposes, perhaps I should publish the
results.
Ext3 is simply ext2 with journalling, as such it is different to XFS,
ReiserFS and IBM's JFS which are intended to provide more advanced
filesystem capabilities generally (including journalling).
Apart from the more general extention of capabilities, there are two main
differences (at a technical level) between ext3 and the others. One is the
work involved in converting from ext2, ext3 is the only one where one can
convert without having to use dump and restore, for that reason if your
main need is to add journalling to an existing system and have the system
down for the minimum time while converting then it is the one to go for.
The other difference from what I have read is that ext3 allows journalling
of the file content data as well as the metadata, the other three (as far
as I can see) only journal metadata. This may be important to you.
> I already know that for now ACLs only work with XFS (because the EA/ACL
> project doesn't support ext3 yet, and ReiserFS is waiting until version 4
> to start implementing ACLs). So that's one difference (with XFS winning
> over the two other alternatives).
>
I don't know about the EA/ACL project, but RSBAC seems to run happily on
ext3, you just have to be a little careful about the patches or you dont
get access control on files in an ext3 filesystem.
> Does anyone have information on performance? Space utilization?
> Reliability when recovering from unclean shutdowns?
>
Ext3 performance is almost identical to ext2, this may be a definite down
for you.
As to reliability, I have had no problems with ext3. I understand that
Sourceforge converted all their existing filesystems to ext3 around
October last year and have been using ReiserFS on all new filesystems
since the same time.
--
Keith Matthews
Frequentous Consultants - Linux Services,
Oracle development & database administration
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