BTRFS: The Good, The Bad and The Ugly

[Martin Langhoff]

On Thu, Jul 14, 2011 at 5:10 AM, JB <jb.1234abcd at gmail.com> wrote:
> Well, then you have to read the thread more carefully before you bark back -
> right in the first OP's post you have references, e.g.
>
> https://lkml.org/lkml/2010/6/18/144

Heh - now that you provide links it's better... anyway, that's a
completely hilarious email you're linking to.

"All such modifications must be reviewed by specialists in the theory
of algorithms."

I love it. Can you get some of those specialists to review the
progress of all the other filesystems in use? ext2, 3, xfs, ReiserFS?

> Here is one more:
> http://www.ilsistemista.net/index.php/linux-a-unix/6-linux-filesystems-benchmarked-ext3-vs-ext4-vs-xfs-vs-btrfs.html

Well, that's interesting. It is a pretty old benchmark, and it shows
btrfs has is slower ins some operations -- on the other hand, it has
some fantastic new features that the other FSs don't have. It's a
tradeoff.

> They all confirm the same picture !

The only picture here is that people who don't understand filesystems
are talking nonsense.

Myself, I use btrfs on some of my F14/F15 machines, and it's been
rock-solid. Some things are slower - yep - but competing in
performance with ext3/4, which has had decades of fine-tuning is...
quite unfair.

All FSs have some use-cases where they are... inappropiate. For
example, ext3 is very badly behaved (performance-wise) in
Maildir-based email servers due to directory fragmentation issues;
similarly, any journalled filesystem will be inefficient tracking the
transaction log of a database (pg_xlog).

So far, it looks that having VM "disks" as files on BTRFS partition
sucks in performance -- ok, not a big deal. Just use a different FS
for your VM disks _or_ take the slowdown _or_ be helpful to people
trying to address the problem.

cheers,



m
-- 
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 martin at laptop.org -- Software Architect - OLPC
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