BTRFS and the steadily lit LED

BTRFS and the steadily lit LED

[Swâmi Petaramesh]

Hi guys,

After having received strong advice from the people in this list to
upgrade my kernel to the latest one, I have installed 3.8.0-14-generic
#24-Ubuntu SMP x86_64 on several (4) machines.

In the hope of improving systems speed I had also removed all snapshots
then defragged the FSes - the snapshots have been recreated since, as I
use the excellent SuSE "Snapper" tool.

But well, all 4 machines are still slow like hell. All of them are used
for quite basic daily tasks - web browsing, email, typical LibreOffice
tasks, nothing very mysterious there, no specific heavy DB work.

All machines have 64-bits Linuxes (either Ubuntu 12.10 or 13.04ß), with
decent amounts of RAM - 2 GB to 4 GB - and disks filled less than 75%

With such a setup, I would expect any decent filesystem to deliver
excellent performance. Still, all of my machines are slow like hell and
I'm most of the time in mode « Working my patience while waiting for the
HD LED to go off ».

I haven't noticed any real-life noticeable improvement upgrading the
kernels from 3.5.x to 3.8.x

So I'm wondering...

-- 
Swâmi Petaramesh <swami@petaramesh.org> http://petaramesh.org PGP 9076E32E
Ne cherchez pas : Je ne suis pas sur Facebook.

Re: BTRFS and the steadily lit LED

[Jérôme Poulin]

On Wed, Mar 27, 2013 at 4:56 AM, Swâmi Petaramesh <swami@petaramesh.org> wrote:
> After having received strong advice from the people in this list to
> upgrade my kernel to the latest one, I have installed 3.8.0-14-generic
> #24-Ubuntu SMP x86_64 on several (4) machines.
>
> In the hope of improving systems speed I had also removed all snapshots
> then defragged the FSes - the snapshots have been recreated since, as I
> use the excellent SuSE "Snapper" tool.
>
> But well, all 4 machines are still slow like hell. All of them are used
> for quite basic daily tasks - web browsing, email, typical LibreOffice
> tasks, nothing very mysterious there, no specific heavy DB work.
>
> All machines have 64-bits Linuxes (either Ubuntu 12.10 or 13.04ß), with
> decent amounts of RAM - 2 GB to 4 GB - and disks filled less than 75%
>
> With such a setup, I would expect any decent filesystem to deliver
> excellent performance. Still, all of my machines are slow like hell and
> I'm most of the time in mode « Working my patience while waiting for the
> HD LED to go off ».
>
> I haven't noticed any real-life noticeable improvement upgrading the
> kernels from 3.5.x to 3.8.x
>
> So I'm wondering...

I must say after having used BTRFS for quite some time on many
different desktop systems that this pretty much summaries my though of
BTRFS used on a desktop system.

I have been using it on my root filesystem for 5 consecutive systems
and all of them were I/O bound most of the time after 2 months of
normal usage with or *without* snapshots. Defragging or rebalancing
doesn't help, growing leaf size helps push back the problem, but it
eventually come back.

The only way to get around the problem is to re-format the drive and
restore from backups. I'm pretty sure I toasted 2 SSDs because of
BTRFS, one in 4 months, the other in 6 months. 80 GB SSDs, I switched
this system to NILFS2 for now, which isn't I/O bound and doesn't kill
flash drives.

A bigger system that I administer has 14 TB worth of data and has
constant loads of 6 to 8 (4 CPUs), mostly because of I/O wait just
because it unzips a file. This system never had a snapshot.

On the system I'm writing, watching a YouTube video will hang one
second every 30 seconds because flash player writes the video to /tmp.

I submitted some backtrace but lost hope, I used kernel from 3.0 to
3.9-rc4 with the FS, features are great, it is great for a file
server, but for desktop, it is really hard to use as root or /home
because of this issue.

Is there any data I can submit to help enhance performance on a desktop system?