Is btrfs ready for use?

13 respostas [Última entrada]
Daemonax
Desconectado
Joined: 09/30/2009

I have just ordered a 2TB drive which should arrive today. I'm trying to decide which filesystem to go with. Is btrfs ready for use, or should I go with ext4, or perhaps something else?

akirashinigami

I am a member!

I am a translator!

Desconectado
Joined: 02/25/2010

According to Wikipedia, there isn't a stable release of btrfs yet. I haven't had any trouble with ext4, so I don't see any reason to use something that's still experimental.

ruben
Desconectado
Joined: 09/24/2010

> According to Wikipedia, there isn't a stable release of btrfs yet. I
> haven't had any trouble with ext4, so I don't see any reason to use
> something that's still experimental.

Ext* filesystems are painful to use on big disks, as they are regularly
checked (every 24 mounts or something like that) in a very slow
process. I would use xfs instead (that is the reason /home is xfs by
default in Trisquel).

Magic Banana

I am a member!

I am a translator!

Desconectado
Joined: 07/24/2010

Ext4 is much faster than ext3 when it comes to checking the file system! If you do not want to try by yourself, see, for instance, the fourteenth slide of http://www.linux-kongress.org/2009/slides/ext4-fast-fsck_ted_tso.pdf (a real-life 70 GB Ubuntu system: 211.0 seconds with ext3 vs. 18.75 seconds with ext4).

Although Btrfs is the future, it is still tagged as "experimental" in the Linux kernel. You do not want to use an experimental file system to store your data. For correct performances with large files, you either want ext4 or XFS (as Rubén suggests).

ruben
Desconectado
Joined: 09/24/2010

> 70 GB Ubuntu system: [...] 18.75 seconds with ext4

At that pace, checking a 2TB disk takes eight minutes. Xfs takes zero.

Magic Banana

I am a member!

I am a translator!

Desconectado
Joined: 07/24/2010

True. I was only pointing out that it is quite unfair to talk about "ext*" when it comes to file system checks. In this regard, ext4 is much faster than ext3.

tului

I am a member!

Desconectado
Joined: 04/29/2011

You can disable the counted checking with
tune2fs -c 0 /dev/sdX
or even at filesystem creation. The newer code base for e2fsprogs actually switches the default to never checking based on number of mounts or time. See the following URL for the changelog stating this.

http://git.kernel.org/?p=fs/ext2/e2fsprogs.git;a=blobdiff;f=RELEASE-NOTES;h=304af0b3ba0989e5f54f418681af30ad676fc860;hp=574ce91d0c2b6fd58d75b9e7bc57798dfa4aaa20;hb=c0b3deb5...

Daemonax
Desconectado
Joined: 09/30/2009

My reason for wanting to use btrfs is because the developers of the Linux kernel say that ext4 is just something to use until btrfs is ready.

Also the fact that with a 2TB drive, which I expect will get filled in a couple of months, I won't be able to stick the data some other place, upgrade to btrfs and then copy the data back.

I have heard that they are not going to be changing the on-disc filesystem.

Apparently Fedora 16 will be using it as the default, so it's probably close to ready.

Magic Banana

I am a member!

I am a translator!

Desconectado
Joined: 07/24/2010

In a few months, Btrfs should indeed be ready. A lot of work has already been achieved for the recent Linux 3.0 release. However a significant piece is currently missing from the userland: a checking tool (à la fsck). The reason is: the developers want to test it on hundreds of corrupted file systems before the release. Until then, Btrfs should definitely not be used to store data you would care missing.

Cyberhawk

I am a translator!

Desconectado
Joined: 07/27/2010

Mr. Torvalds wants to jump right to 3.0 from this point? That is quite amazing.

Silly me, 3.0 is already out and considered stable by the kernel.org. Have to go find information why he called the next version 3.0 instead of 2.6.40 or so.

Cyberhawk

I am a translator!

Desconectado
Joined: 07/27/2010

Appears he just isn't very comfortable with counting as high as 40. That's literally what he said. Kind of disappointed now.

Magic Banana

I am a member!

I am a translator!

Desconectado
Joined: 07/24/2010

You will be disappointed. The reason was given in this mail ( https://lwn.net/Articles/445222/ ):
I decided to just bite the bullet, and call the next version 3.0. It
will get released close enough to the 20-year mark, which is excuse
enough for me, although honestly, the real reason is just that I can
no longe rcomfortably count as high as 40.

And, indeed, no new feature justifies the jump.

akirashinigami

I am a member!

I am a translator!

Desconectado
Joined: 02/25/2010

I stumbled across this today (https://btrfs.wiki.kernel.org/index.php/Conversion_from_Ext3). Apparently, it's possible to convert an ext3/4 filesystem into a Btrfs one, so you could use ext4 until Btrfs becomes stable.

Daemonax
Desconectado
Joined: 09/30/2009

On Tue, 2011-08-02 at 08:53 +0200, name at domain wrote:
> I stumbled across this today
> (https://btrfs.wiki.kernel.org/index.php/Conversion_from_Ext3). Apparently,
> it's possible to convert an ext3/4 filesystem into a Btrfs one, so you could
> use ext4 until Btrfs becomes stable.

Great, thanks. I decided to go with Ext4, so being able to convert to
btrfs in the future is great.