Distro vs latest kernel for BTRFS?

Distro vs latest kernel for BTRFS?

[Shriramana Sharma]

Hello. I've seen repeated advices to use the latest kernel. While
hearing of the recent compression bug affecting recent kernels does
somewhat warn one off the previous advice, I would like to know what
people who are running regular distros do to get the latest kernel.

Personally I'm on Kubuntu, which provides mainline kernels till a
particular point but not beyond that.

Do people here always compile the latest kernel themselves just to get
the latest BTRFS stability fixes (and  improvements, though as a
second priority)?

-- 
Shriramana Sharma ஶ்ரீரமணஶர்மா श्रीरमणशर्मा

Re: Distro vs latest kernel for BTRFS?

[Austin S Hemmelgarn]

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On 2014-08-22 07:59, Shriramana Sharma wrote:
> Hello. I've seen repeated advices to use the latest kernel. While
> hearing of the recent compression bug affecting recent kernels does
> somewhat warn one off the previous advice, I would like to know what
> people who are running regular distros do to get the latest kernel.
> 
> Personally I'm on Kubuntu, which provides mainline kernels till a
> particular point but not beyond that.
> 
> Do people here always compile the latest kernel themselves just to get
> the latest BTRFS stability fixes (and  improvements, though as a
> second priority)?
> 
I personally use Gentoo Unstable on all my systems, so I build all my
kernels locally anyway, and stay pretty much in-line with the current
stable Mainline kernel.
Interestingly, I haven't had any issues related to either of the
recently discovered bugs, despite meeting all of the criteria for being
affected by them.


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Re: Distro vs latest kernel for BTRFS?

[Duncan]

Austin S Hemmelgarn posted on Fri, 22 Aug 2014 08:04:12 -0400 as
excerpted:

> On 2014-08-22 07:59, Shriramana Sharma wrote:
>> Hello. I've seen repeated advices to use the latest kernel. While
>> hearing of the recent compression bug affecting recent kernels does
>> somewhat warn one off the previous advice, I would like to know what
>> people who are running regular distros do to get the latest kernel.
>> 
>> Personally I'm on Kubuntu, which provides mainline kernels till a
>> particular point but not beyond that.
>> 
>> Do people here always compile the latest kernel themselves just to get
>> the latest BTRFS stability fixes (and  improvements, though as a second
>> priority)?
>> 
> I personally use Gentoo Unstable on all my systems, so I build all my
> kernels locally anyway, and stay pretty much in-line with the current
> stable Mainline kernel.
> Interestingly, I haven't had any issues related to either of the
> recently discovered bugs, despite meeting all of the criteria for being
> affected by them.

Semantics but FWIW some people prefer for that to be called testing, not 
unstable.  Gentoo doesn't have an official whole-tree unstable level, tho 
in effect that's what you get if you enable the various project overlays 
and unmask the non-live packages, so one could say it's per-project or 
per-package.

But of course without an official unstable level, the distinction between 
testing and unstable is rather blurred, so some people call it unstable, 
as opposed to stable, too.  But some don't like the "unstable" 
connotation, and technically, it /is/ closer to Debian's "testing" than 
their "unstable", and I don't know anyone else using the "unstable" 
label, so...

Meanwhile, while I'm on gentoo as well, I've been configuring and 
building my own kernels since shortly after I switched to Linux 
(Mandrake, at the time) instead of MS eXPrivacy, which I refused to do on 
principle.  As a matter of fact, while I had done a bit of experimenting 
before and had taken some time researching the switch, I began my big 
switch for real the week eXPrivacy came out.  After a decade on MS, my 
feelings were with FLOSS but my experience was all on MS so I honestly 
don't know when/if I would have switched without the eXPrivacy line I 
simply wasn't going to cross as a push from MS, so ironically I have MS 
to thank for pushing me to freedomware. =:^)

Anyway, unlike Marc Merlin by the time I switched to Linux you weren't 
expected to build your own kernel, but I learned it within the first 
three months as I was still dual booting and switching one task after 
another to my new Linux platform.  I learned because as a critical part 
of my freedomware platform it was important to me to do so.  And I've 
been building my own kernel, using a set of scripts I've maintained[1] 
over the years to do so, since then.  When I switched to gentoo, I simply 
took the scripts I already had with me, changing them slightly for the 
new environment, as I hadn't setup the separate config file I use these 
days.

These days I fetch, configure and build directly from Linus' git repo, 
still using my scripts set to help me do so. =:^)

While you may not consider Gentoo a "normal distro", presumably you 
consider Mandriva such a distro, it being the successor to the Mandrake 
on which I started doing my own kernel builds.

---
[1] Scripts I've maintained:  FWIW, I learned bash/shell by tearing apart 
and recoding the Mandrake initscripts, getting a practical understanding 
of shell scripting as actually used on a system in the process.  To me, 
tho I've switched to systemd that's arguably the biggest loss of doing 
so, as newbies no longer have the opportunity to bootstrap their own 
shell and shell-scripting knowledge on the scripts the system itself 
bootstraps with. =:^(

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

Re: Distro vs latest kernel for BTRFS?

[Rich Freeman]

On Fri, Aug 22, 2014 at 8:04 AM, Austin S Hemmelgarn
<ahferroin7@gmail.com> wrote:
>>
> I personally use Gentoo Unstable on all my systems, so I build all my
> kernels locally anyway, and stay pretty much in-line with the current
> stable Mainline kernel.

"Gentoo Unstable" probably means gentoo-sources, testing version,
which follows the stable kernel branch, but the most recent stable,
and not the long-term stable.  gentoo-sources stable version generally
follows the most recent longterm stable kernel (so 3.14 right now).
I'm not sure what the exact policy is, but that is my sense of it.

So, you're still running a stable kernel most likely.  If you really
want mainline then you want git-sources.  That follows the most recent
mainline I believe.  Of course, if you're following it that closely
then you probably should think about just doing a git clone and
managing it yourself, since then you can handle patches/etc more
easily.

I think the best option for somebody running btrfs is to stick with a
stable kernel branch, either the current stable or a very recent
longterm.  I wouldn't go back into 3.2 land or anything like that.

But, yes, if you had stuck with 3.14 and not gone to the current
stable then you would have missed the compress=lzo deadlock.  So, pick
your poison.  :)

Rich

Re: Distro vs latest kernel for BTRFS?

[Austin S Hemmelgarn]

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On 2014-08-22 14:22, Rich Freeman wrote:
> On Fri, Aug 22, 2014 at 8:04 AM, Austin S Hemmelgarn
> <ahferroin7@gmail.com> wrote:
>>>
>> I personally use Gentoo Unstable on all my systems, so I build all my
>> kernels locally anyway, and stay pretty much in-line with the current
>> stable Mainline kernel.
> 
> "Gentoo Unstable" probably means gentoo-sources, testing version,
> which follows the stable kernel branch, but the most recent stable,
> and not the long-term stable.  gentoo-sources stable version generally
> follows the most recent longterm stable kernel (so 3.14 right now).
> I'm not sure what the exact policy is, but that is my sense of it.
> 
> So, you're still running a stable kernel most likely.  If you really
> want mainline then you want git-sources.  That follows the most recent
> mainline I believe.  Of course, if you're following it that closely
> then you probably should think about just doing a git clone and
> managing it yourself, since then you can handle patches/etc more
> easily.
> 
> I think the best option for somebody running btrfs is to stick with a
> stable kernel branch, either the current stable or a very recent
> longterm.  I wouldn't go back into 3.2 land or anything like that.
> 
> But, yes, if you had stuck with 3.14 and not gone to the current
> stable then you would have missed the compress=lzo deadlock.  So, pick
> your poison.  :)
> 
> Rich
> 
By saying 'unstable' I'm referring to the stuff delimited in portage
with the ~ARCH keywords.  Personally, I wouldn't use that term myself
(all of my systems running on such packages have been rock-solid stable
from a software perspective), but that is how the official documentation
refers to things with the ~ARCH keywords.  There are a lot of Gentoo
users who don't know about the keyword thing other than as an occasional
inconvenience when emerging certain packages, so I just use the same
term as the documentation.

For the record, I am using the gentoo-sources package, but instead of
using what they mark as stable (which is 3.14), I'm using the most
recent version (which is 3.16.1).


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Re: Distro vs latest kernel for BTRFS?

[Marc MERLIN]

On Fri, Aug 22, 2014 at 05:29:29PM +0530, Shriramana Sharma wrote:
> Hello. I've seen repeated advices to use the latest kernel. While
> hearing of the recent compression bug affecting recent kernels does
> somewhat warn one off the previous advice, I would like to know what
> people who are running regular distros do to get the latest kernel.
> 
> Personally I'm on Kubuntu, which provides mainline kernels till a
> particular point but not beyond that.
> 
> Do people here always compile the latest kernel themselves just to get
> the latest BTRFS stability fixes (and  improvements, though as a
> second priority)?

First, yeah you want to stay with 3.14 for now until the last bug that's
been found and is integrated in a stable 3.16.

Yes, I compile my own kernels, but that's mostly because that's what one
did in 1993, and that's what I still do now :)

If you're not comfortable compiling your own kernel (mostly getting the
.config options you want/need), you can
1) use a recent enough vendor kernel 
2) use their .config (or /proc/config.gz) as a way to build a new
kernel.

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/                         | PGP 1024R/763BE901

Re: Distro vs latest kernel for BTRFS?

[Chris Murphy]

On Aug 22, 2014, at 5:59 AM, Shriramana Sharma <samjnaa@gmail.com> wrote:

> Hello. I've seen repeated advices to use the latest kernel. While
> hearing of the recent compression bug affecting recent kernels does
> somewhat warn one off the previous advice, I would like to know what
> people who are running regular distros do to get the latest kernel.
> 
> Personally I'm on Kubuntu, which provides mainline kernels till a
> particular point but not beyond that.
> 
> Do people here always compile the latest kernel themselves just to get
> the latest BTRFS stability fixes (and  improvements, though as a
> second priority)?

It's highly variable on this list. I'm lazy so I'm mostly using Fedora kernels from updates repo. But for Btrfs specific testing I use mainline kernels built almost daily from Fedora's koji build system, which don't even make it to the updates-testing repo.

http://koji.fedoraproject.org/koji/packageinfo?packageID=8

I only compile kernels if I'm testing a particular patch. Although I did build a kernel based on the original git pull for 3.17 just because it was a big pile of stuff and figured it was worth testing some old bugs against. So it really depends on your setup, workload, if you're testing patches, etc. The problems with 3.15 and 3.16 were unusual.


Chris Murphy

Re: Distro vs latest kernel for BTRFS?

[Martin Steigerwald]

Am Freitag, 22. August 2014, 17:29:29 schrieb Shriramana Sharma:
> Hello. I've seen repeated advices to use the latest kernel. While
> hearing of the recent compression bug affecting recent kernels does
> somewhat warn one off the previous advice, I would like to know what
> people who are running regular distros do to get the latest kernel.
> 
> Personally I'm on Kubuntu, which provides mainline kernels till a
> particular point but not beyond that.
> 
> Do people here always compile the latest kernel themselves just to get
> the latest BTRFS stability fixes (and  improvements, though as a
> second priority)?

I compile own kernel on my main laptop cause I want to follow kernel 
development closely for my Linux Performance analysis and tuning trainings and 
also help a bit with testing things.

I don´t compile kernels on any other machines anymore. Instead I use what 
Debian Sid gives me. On the server VM I use 3.14 Debian Wheezy Backports 
kernel, an will continue to do so, until I know a 3.16 package with BTRFS fixes 
hits the backports repo.

I recommend against SLES 11 SP 3 stable kernel. Their 3.0 had serious free 
space issues in one VM after *just* installing OpenLDAP and have snapper 
continue with the snapshotting. It was still 2GB free, but I was not able to 
delete files or delete snapshots anymore. I think I also try rebalancing the 
FS. After a while I gave up and reverted to a previous VM snapshot.

I know this is supported officially, but I don´t think this is anywhere near 
production ready. SLES 12 should be much better as its using a newer kernel.

On any account long time enterprise Linux kernels may easily become outdated. 
I know they are backporting things, but I think for BTRFS its better to follow 
new kernels as is more timely.

With the distros that release all 6 months or so, I think you get recent 
enough kernel easily. With Debian you can use backport kernels. Some distros 
have additionally kernel repos for more recent kernels. And I in the end I 
think you can even install newer kernel packages on enterprise distros, but… 
you loose support this way.

For Kubuntu / Ubuntu I think there even is a daily kernel PPA. I think 
Phoronix uses it for their daily performance regression testing (and making 
big noise of regressions even in RC kernels).

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

Re: Distro vs latest kernel for BTRFS?

[Qu Wenruo]

Personally, if doing development, compiling from latest stable or 
integration kernel is my choice.

But if not developing the codes, I prefer Arch's core repo, which is 
about 1~2 weeks late than the stable release.
Although somewhat late, but still much newer than most distros' stable repo.
(I also used to use Gentoo, but even with ccache, compiling everything 
is somewhat time killing and overkilled for me)

Thanks,
Qu
-------- Original Message --------
Subject: Distro vs latest kernel for BTRFS?
From: Shriramana Sharma <samjnaa@gmail.com>
To: linux-btrfs <linux-btrfs@vger.kernel.org>
Date: 2014年08月22日 19:59
> Hello. I've seen repeated advices to use the latest kernel. While
> hearing of the recent compression bug affecting recent kernels does
> somewhat warn one off the previous advice, I would like to know what
> people who are running regular distros do to get the latest kernel.
>
> Personally I'm on Kubuntu, which provides mainline kernels till a
> particular point but not beyond that.
>
> Do people here always compile the latest kernel themselves just to get
> the latest BTRFS stability fixes (and  improvements, though as a
> second priority)?
>