[gentoo-user] Ext4 another thread

[gentoo-user] Ext4 another thread

[Harry Putnam]

I didn't want to derail the existing thread discussing ext4 with this
angle ... I'm guessing there may be comments that will not be helpful
to that OP.

I'm wondering what people running ext4 are seeing in practice that
makes it better than ext3 or reiserfs? Is it safer journalling? Faster
read/write? ...

I've thought about switching over too... especially every time I
`rm -rf' something big and it seems to take way longer than I'd like.

(I run all reiserfs except ext2 for /boot)

Re: [gentoo-user] Ext4 another thread

[Paul Hartman]

On Fri, Jan 30, 2009 at 12:49 PM, Harry Putnam <reader@newsguy.com> wrote:
> I didn't want to derail the existing thread discussing ext4 with this
> angle ... I'm guessing there may be comments that will not be helpful
> to that OP.
>
> I'm wondering what people running ext4 are seeing in practice that
> makes it better than ext3 or reiserfs? Is it safer journalling? Faster
> read/write? ...
>
> I've thought about switching over too... especially every time I
> `rm -rf' something big and it seems to take way longer than I'd like.
>
> (I run all reiserfs except ext2 for /boot)

On my desktop, I'm using ext3 via ext4's driver (on-disk format is
still ext3). There are theoretical improvements but I haven't noticed
anything honestly.

On my laptop I converted to actual ext4 format and don't notice
anything different... I did not do any tests or take any measurements,
but there was no "wow" factor or anything. It just works normally.

Both of these are single-user home computers. Maybe someone in a
high-load environment has better ideas about it.

Re: [gentoo-user] Ext4 another thread

[Albert Hopkins]

On Fri, 2009-01-30 at 12:49 -0600, Harry Putnam wrote:
> I didn't want to derail the existing thread discussing ext4 with this
> angle ... I'm guessing there may be comments that will not be helpful
> to that OP.
> 
> I'm wondering what people running ext4 are seeing in practice that
> makes it better than ext3 or reiserfs? Is it safer journalling? Faster
> read/write? ...
> 
> I've thought about switching over too... especially every time I
> `rm -rf' something big and it seems to take way longer than I'd like.
> 
> (I run all reiserfs except ext2 for /boot)

Well it's new and new is always interesting (in good ways and bad ;).

Large writes/deletes will be faster.  If you don't do (a lot of)
writes/deletes of large files then you won't notice (as much).  Extents,
better allocation/deallocation methods, and other added logic further
makes improvements on files (esp large files).  It will eventually
support much larger filesystems and subsecond timestamps for those with
the need.

Depending on your usage you might see significant improvements or hardly
any at all.  Best way to know for sure is to try it out.  Note however
that on ext4 journal checksums are *on* by default (and off on ext3
iirc). So when you are comparing performance you should make that value
the same for both for a fair comparison.

Re: [gentoo-user] Ext4 another thread

[Dirk Heinrichs]

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Am Freitag, 30. Januar 2009 19:49:33 schrieb Harry Putnam:

> I didn't want to derail the existing thread discussing ext4 with this
> angle ... I'm guessing there may be comments that will not be helpful
> to that OP.
>
> I'm wondering what people running ext4 are seeing in practice that
> makes it better than ext3 or reiserfs? Is it safer journalling? Faster
> read/write? ...

That's indeed an interesting question. I'd say to some extend it's answered in 
[1]. However, to me it looks like just another filesystem in the classical 
sense. The one that really brings something new to the Linux filesystem world 
will be btrfs. I've already tried some older versions of it and it looks very 
promising. Volumes, RAID, data integrity, etc, all integrated into the 
filesystem, similar to Suns ZFS.

Bye...

	Dirk

[1]: http://kernelnewbies.org/Ext4



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[gentoo-user] Re: Ext4 another thread

[Harry Putnam]

Albert Hopkins <marduk@letterboxes.org> writes:

> Depending on your usage you might see significant improvements or hardly
> any at all.  Best way to know for sure is to try it out.  Note however
> that on ext4 journal checksums are *on* by default (and off on ext3
> iirc). So when you are comparing performance you should make that value
> the same for both for a fair comparison.

What about comparisons to reiserfs... any comments on that.  Far as
I've experienced it with reiserfs... it puts ext3 in the shade in most
ways. 

[gentoo-user] Re: Ext4 another thread

[Nikos Chantziaras]

Harry Putnam wrote:
> I didn't want to derail the existing thread discussing ext4 with this
> angle ... I'm guessing there may be comments that will not be helpful
> to that OP.
> 
> I'm wondering what people running ext4 are seeing in practice that
> makes it better than ext3 or reiserfs? Is it safer journalling? Faster
> read/write? ...

http://www.phoronix.com/scan.php?page=article&item=ext4_benchmarks&num=1

It's faster.