Arch Linux

grizlak

Member

Registered: 2010-02-19

Posts: 7

I/O slows down the system

Hi,

Can you suggest any techniques for making I/O operations "lighter" on the system as a whole?

I have a fairly modern workstation (Core 2 Duo, 2 GB RAM, standard SATA hard disk) running standard Arch kernel. I run a very light environment (dwm) and usually have several applications running at the same time, but nothing resources-heavy (Firefox, Thunderbird, a couple terminals). The system works great in terms of speed and reactivity until a long disk operation kicks in. Once I start copying or moving big files (or big numbers of files) around, either between partitions on the HDD, or between the HDD and let's say an USB stick, the applications become very slow and operations such as switching between virtual workspaces take ages.

Any suggestions? Any settings or kernel tweaks that can help here?

Stebalien

Member

Registered: 2010-04-27

Posts: 1,239

Website

Re: I/O slows down the system

You can try the ck, pf, or zen kernel (with bfq enabled) and/or try setting the io priority of long-running io-intensive tasks to idle (or at least a lower priority).

ionice -c 3 <command>
-- or --
ionice -c 3 -p <pid>

Last edited by Stebalien (2011-08-06 17:58:58)

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nawitus

Member

Registered: 2009-05-11

Posts: 112

Re: I/O slows down the system

I remember reading that vm.swappiness has an effect here (try increasing it) How large is your swap partition? Also try different I/O schedulers (like deadline if you're using jfs).

graysky

Wiki Maintainer

From: :wq

Registered: 2008-12-01

Posts: 10,697

Website

Re: I/O slows down the system

If your hdd has NCQ and AHCI enabled, try noop as your IO scheduler rather than cfq.

https://bbs.archlinux.org/viewtopic.php?id=123427

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