heavy disk usage brings system to it's knees, what am I missing?

[saturn-vk]

hello,
my system is on a single 200G seagate hd [ST3200822A].
hdparm says this of the hd:

/dev/hda:
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 1 (on)
readonly = 0 (off)
readahead = 256 (on)
geometry = 24321/255/63, sectors = 390721968, start = 0

the problem here is, under heavy usage (heavy swap, hash checking, etc), when there's 6-12MB/s of activity on the disc, the system becomes almost unresponsive. It's something like when the cpu usage goes to 100% during the old non-preemptive days.

so what am i missing? is there some option i can turn on so that the system stays responsive during these periods of heavy hd usage?

[nevin180]

Try the "Add To Cart" button for some more RAM on newegg.com... sorry ;-)

If you're swapping heavily, then you can't do much other than add RAM.

Cheers

[leonpmu]

Please give the rest of your system specs too, perhaps we can see exactly where the bottle neck is. Also what apps are you running or are you trying to do when this happens?

[sharth]

During heavy swapping, your system will always turn to mud. hard-drives are just simply slower than ram, and because of this, everything slows down. The only way to fix that is to buy more ram.

As for the md5summing, I would probably think that this is also along the same lines. when this next happens, run free -m and let us see the output of that.

[saturn-vk]

the most recent slowdown saw during a torrent check. with only 6MB/s, the system was considerably slow. During that time, free -k read out:

total used free shared buffers cached
Mem: 905552 895516 10036 0 3872 471580
-/+ buffers/cache: 420064 485488
Swap: 979956 492904 487052

as you can all see, only half of the available 1GB ram is used.

the other relevant system part, the cpu is a athlon xp 2500+, which, for this event, was mostly unused.

[rocketpcguy]

maybe your motherboard harddrive controller wasn't optimized in your kernel? just for reference, my 2.4Ghz pc has 22% system usage when i md5sum a DVD iso on the hard drive, and 10% usage when copying files to another harddisk, both hard disks with an unoptimized hdparm settings:
multcount = 16 (on)
IO_support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 256 (on)

[psilo]

What does top say? Which proces is on top? Is the cpu using all its cycles on user ( % us) or system (% sy) cycles?

[psych-major]

If you're not using all your RAM, why are you swapping heavily?
If swap is the issue, you might try throwing a 2-4 gig hard drive in and making it your swap partition. You should be able to get a drive of this size for about $.50 on eBay.