Re: I/O or Threading Suffer

> Ah. now that's a different story.  You're out of the control of the
> process scheduler and into the disk.  I don't suppose you're using an
> IDE/ATA disk with no tagged queueing? :) Run "dmesg | grep depth.queue"
> to see how many requests can be queued up on your disk at once.
>
> That dd is stuffing lots of dirty data into the disk cache, and all the
> other processes have to wait in line to get their I/Os done.  You'll
> see much better results from a SCSI disk (with usual queue depths
> between 32 and 64), and even better results from a multi-disk hardware
> RAID array (which will have a large write cache).
>
> --
> Dan Nelson
> dnelson_at_allantgroup.com
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>
when system doesnt response any more in cause of high write operations
on the disk then the reason for this is not looked up in the device device
configuration or in non-scsi hardware ;)