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BTRFS installation

Posted: Sun Dec 09, 2012 4:36 pm
by Jenia
So I hear we'll be a having an UP6 soon - and with it, a pair of new isos, one for mate, and one for cinnamon.

When we last had a respin, I had a machine I could "experiment" on, so I tried installing LMDE on a BTRFS partition. Needless to say, the installer didn't cooperate with me - it kept insisting to format the thing into ext4.
Whether I did something wrong at the time - or not - is not the issue.

Come UP6 and the ISOs, will BTRFS installs be supported?

Re: BTRFS installation

Posted: Mon Dec 10, 2012 3:34 am
by killer de bug
Don't think so !

The kernel is still the 3.2. BTRFS is fully supported with 3.5 and 3.6 I think. You will need to wait a little bit more or... upgrade the kernel on your own using SID repo. :wink:

Re: BTRFS installation

Posted: Mon Dec 10, 2012 6:18 am
by Jenia
I need to install the OS to upgrade the kernel, and the OS needs an ext4 file system, which I need to remove so that I can put in a btrfs file system, which requires removing the OS from it, along with the kernel... :lol:

Re: BTRFS installation

Posted: Mon Dec 10, 2012 6:27 am
by sobrus
you can install lmde on btrfs, i've done it already with UP4.
Installer defaults to ext4 but you can change it to whatever you want, and don't forget to disable root fsck at boot time.

But btrfs is still experimental, no matter what kernel are you using. if you don't plan to use its new features, there is no point in using it.
I've been using btrfs for many months, with kernels up to 3.6.x and all I can say is that ext4 is usually both more stable and faster.

Re: BTRFS installation

Posted: Mon Dec 10, 2012 9:49 am
by Jenia
Truly? Hmm, for some reason I thought btrfs was faster, and stable enough on machines immune to sudden loss of power...

Not like I'd know how to disable fsck on startup anyway.

Re: BTRFS installation

Posted: Mon Dec 10, 2012 1:24 pm
by sobrus
btrfs usually isn't any faster unless you have very slow drive and fast cpu with compression enabled. Very often it is much slower.
Some benchmarks use compressible data to test speed. It gives btrfs artificial big speed gain.

Also, since btrfs is copy-on-write system it suffers from massive fragmentation (unlike ext4), and suffers performance penalty when volume becomes full (garbage collection needed).
In fact, btrfs reserves 2GB of each partition for its own use.

I've lost my /home partition two times even though I do have UPS. If you computer freeze for whatever reason, filesystem may be badly damaged too. So I gave up using it.

To disable fsck, just make sure you have "0 0" at the end of root mount entry in /etc/fstab. Usually it is "1 2" or something like that.
But for pure performance, it would be much better to tune ext4 (for example enabling journal_async_commit may give nice boost).

Re: BTRFS installation

Posted: Sun Feb 03, 2013 11:28 am
by penzoiders
Btrf can be faster if you use compression, I suggest zlib, also have TRIM option, good for SSD, but the most important thing is that you can snapshot your volumes, you can convert it in RAID kind of thing in future and this cag give you better performances than mdraid. ... ebian.html

I think btrfs is great future-proof ssd-ok filesystem, I'm using it also @work on my production server to store the KVM storage pool.. live snapshots at zero cost.

Is still under heavy development but it's definitely safe to use.