As far as I understand, you always need an fsck tool. You can design a COW FS to make sure that if a OS crash or a power failure happens in the middle of a write, you can restore back to the last flushed coherent state.
But that only deals with OS crashs or power failures. If you have a disk error for instance, and you manage to extract the data out of the disk, you may want to rebuild a coherent state which omits the corrupted parts. But to be honest, I don't know how btrfs does that or if it does. I've been using btrfs for 6month and came back to ext4 due to the silly metada allocation space full which did not reported the FS as being full and prevented me from booting my OS three times after I upgrade the distribution. Believe, when you have no internet access and you tries to fix that from a busybox emergency environment, it drives you crazy not to even be able to issue "rm" because you get ENOSPC. I got angry and reformatted all my volume, even if i know that this issue has been addressed since then.
Anyway, fsck was just an example for my point, the compression or dedup cases still apply.
Try 6 years. Development began in late 2007.
Originally Posted by mark45
Compare to ZFS. Development started in 2001. Then ZFS was included in the June 2006 update of Solaris 10. That is 5 years from beginning of development to deployment in a production OS.
But ZFS pioneered a lot of new filesystem concepts. btrfs already had all of those ideas available to build on in 2007, so btrfs should have been ready faster than ZFS. Implementation should be faster when you do not need to invent the wheel (only reinvent it).
Instead, after 6 years of development, btrfs is still not ready to be the default root filesystem of a stable OS release.
Unfortunately, I think it is evident that the project management of btrfs is ineffective. Announcements like this that the project management is not changing may be meant to be reassuring, but I am not reassured.
Last edited by jwilliams; 12-04-2013 at 05:51 PM.
Why is it news that a developer opens a Facebook acco... oh wait.
It's almost 7 years old
Originally Posted by jwilliams
Author: Chris Mason <email@example.com>
Date: Fri Jan 26 15:51:26 2007 -0500
Btrfs: Initial checkin, basic working tree code
Signed-off-by: Chris Mason <firstname.lastname@example.org>
"After the last FS summit, I started working on a new filesystem that
maintains checksums of all file data and metadata."
I think that he is talking about 2006 fs summit, because 2007 was at February 12–13
I guess Facebook really wants to port over to Btrfs from ext4
Thanks for the correction!
Originally Posted by michal
What do you mean by "plan"? They already have one, and have had it for a while. It's not critical, but it exists.
Originally Posted by Akka
Well, I had a filesystem that got corrupted somehow after a crash. You could still mount it but it behaved 'weird'. The fsck tool detected some errors but wasn't able to correct them - it crashed instead. In the end you're told that the best option is to format. Few months later I read some news about new compression algorithms and some new raid mode in btrfs.
Originally Posted by GreatEmerald
I think this is like the definition of 'having the priorities in the wrong order'.
Blah blah from the sidelines. AFAIK, it is default filesystem for SLES. All your assumptions are just assumptions from a very far distance. Reaching conclusions is a bit rude IMO, because you lack any knowledge or did any investigation at all.
Originally Posted by jwilliams
Originally Posted by bkor