System really slow when using harddrive intense applications

Lazze · 2009-09-02 19:35:03

Hello

I'm having some trouble with my Arch Linux, when using applications which utilize the harddrive alot, extracting archives with squeeze etc. my UI turns very slow, almost impossible to use. I don't know if it's related to compiz.
I have a Core I7 processor and there's a lot of free cpu cycles.

Any ideas why it turns out like this? It doesn't matter if I'm using my primary harddrive where the system is installed or my secondary partition which is running ntfs.

Thanks
// Lazze

broch · 2009-09-02 21:19:46

1) make sure that indexing service is not running

2) compiz schould not affect disk performance, but just in case turn it off
3) install iotop from community and see what is causing the problem
4) change I/O scheduler, CFQ seems like crap recently (deadline or no-op append elevator to kernel line in grub)
5) check for possible errors in log files/dmesg
6) Con Kolivas is back so you can try his scheduler (BFS - brain fuck scheduler). This is still early, so you would have to install zen kernel and try if new I/O scheduler is better for your application. If you also enable schediso x, you may have more responding system. But no quarantees.

Last edited by broch (2009-09-02 21:45:33)

Lazze · 2009-09-02 22:34:12

Thank you

It's getting a bit late now, but I will definitely take a look at it tomorrow.

sand_man · 2009-09-02 23:13:02

Is file IO very slow too? If so, your hard drive might be dying...happened to me recently and I lost 500GB of data

Last edited by sand_man (2009-09-02 23:13:17)

ngoonee · 2009-09-03 00:02:23

sand_man wrote:

Is file IO very slow too? If so, your hard drive might be dying...happened to me recently and I lost 500GB of data

Backup?

And HD-intensive applications do slow things down a lot here as well. Not that I do such things often enough to want to bother. As I recall it was the same with Ubuntu previously.

graysky · 2009-09-03 00:14:01

Known issue w/ kernel

http://bbs.archlinux.org/viewtopic.php?id=71131
http://bbs.archlinux.org/viewtopic.php?id=70525

ngoonee · 2009-09-03 03:49:08

Perhaps if you want to try out the Brain Fuck Scheduler (not my name, the author's), or BFS, you could check it out. It was just released a week ago though, so doubt its very stable. Author purports that the performance is much improved.

broch · 2009-09-03 13:48:05

more @Lazze
take look at your swap.
you may tweak file system with sysctl (but no low or even swappiness=0 idiocy of course!)

More RAM snappier system

My setup (snappy)
fs xfs (custom format flags). I would not go that far as to reformat disk to get not really certain results if you are using something else. This is the last thing I would try (changing fs)

kdemod4.3 (same thing as kde4.3), with compositing effect turned on - no need to change DM, I believe that you can stay with KDE, but you may test something lightweight see if result is better.

I/O scheduler noop or (recently) BFS - you can test any scheduler without patching/rebuilding kernel with exception of BFS and patched CFQ

I don't know if noop is good choice for any other fs than xfs, but deadline is definitely an easy option to test
test:
running
dd if=/dev/zero of=/tmp/test bs=1M count=1M
effect on and opening apps
opening app may take ~30s, once open app is pretty snappy, mouse smooth, window mooving smooth, no issues with desktop refresh.

After killing Con Kolivas project, CFQ supposed to be 'da thing' obviously is not.
I don't bother anymore with compiling CFQ, recent zen kernel (-31-rc8) provides some extra tweaks that supposedly fix CFQ problems, but I believe in simplicity and CFQ is very complex, no way that it ever fulfill promise of being good (desktop) performer.

Again, keep in mind that these are only some pointers, some may work for you some may not.

Last edited by broch (2009-09-03 16:49:43)

Lazze · 2009-09-04 15:40:53

I had this issue on previous installs, and it happens on both of my disks, the disks seems pretty quick, Linux DC++ hashes files at about 70 mb/s but the system looses its snappyness, switching active windows etc. becomes a bit unresponsive. Most times its not extreme but very annying since it shouldn't slow down at all when you're just doing harddrive intense tasks on you secondary drive.

I'll put my mind into it now and I'll return with my results when finished.

Thanks for all the replies, this is what I love about linux and especially the arch community!

Lazze · 2009-09-04 16:58:13

Changing to deadline and editing the swappiness made it a bit better. My applications and desktop rendering feels good now.
But is there any way to make the OS share the harddrive resources a bit better, I don't like to wait 20sec for pidgin to start just because I'm copying a file. I also have problems to watch a 720p movie while I'm extracting it which I'd like to be able to do, it's does it smooth most of the time but about every other minut it freezes for a half a second or so.

My system is pretty strong and I'm only using about 20% ram, so it should be possible.

shining · 2009-09-04 17:24:50

broch wrote:

I/O scheduler noop or (recently) BFS - you can test any scheduler without patching/rebuilding kernel with exception of BFS and patched CFQ

That's maybe because BFS is NOT a I/O scheduler.
http://bbs.archlinux.org/viewtopic.php? … 40#p612940

After killing Con Kolivas project, CFQ supposed to be 'da thing' obviously is not.
I don't bother anymore with compiling CFQ, recent zen kernel (-31-rc8) provides some extra tweaks that supposedly fix CFQ problems, but I believe in simplicity and CFQ is very complex, no way that it ever fulfill promise of being good (desktop) performer.

s/CFQ/CFS ?
CFQ is just a I/O scheduler : http://en.wikipedia.org/wiki/CFQ (afaik, it was the default one used in the -ck patchset, so it was actually the io scheduler recommended by con)
CFS was the competitor of the old ck StairCase, and is the default and only CPU scheduler since 2.6.23 : http://en.wikipedia.org/wiki/Completely_Fair_Scheduler

There is really no need to add more confusion to an already quite complex topic by mixing up acronyms and concepts ...

Arch Linux

#1 2009-09-02 19:35:03

System really slow when using harddrive intense applications

#2 2009-09-02 21:19:46

Re: System really slow when using harddrive intense applications

#3 2009-09-02 22:34:12

Re: System really slow when using harddrive intense applications

#4 2009-09-02 23:13:02

Re: System really slow when using harddrive intense applications

#5 2009-09-03 00:02:23

Re: System really slow when using harddrive intense applications

#6 2009-09-03 00:14:01

Re: System really slow when using harddrive intense applications

#7 2009-09-03 03:49:08

Re: System really slow when using harddrive intense applications

#8 2009-09-03 13:48:05

Re: System really slow when using harddrive intense applications

#9 2009-09-04 15:40:53

Re: System really slow when using harddrive intense applications

#10 2009-09-04 16:58:13

Re: System really slow when using harddrive intense applications

#11 2009-09-04 17:24:50

Re: System really slow when using harddrive intense applications

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