I/O monopoly and I/O control
Dear sir or madam!
Sorry for my bad English.
I have some problem with disk input/output. Any process ("dd", for
example) can use disk input/output at ~100%. For exapmple, run next as root:
# dd if=/dev/zero of=/home/piroman/tmpfile bs=1024 count=12582912
After run, I have very slow system operation. CPU usage = ~20%, Memory
usage = ~90% ( my system has 6 Gb RAM).
There is an opinion that in it there is guilty monopoly usage of disk
input/output.
Hardware characteristic of my system:
1) CPU: 2,4 GHz Core 2 Quad (Q6600)
2) RAM: 6 Gb as 3 modules.
3) Disks: 2x SATA-II + 1 DMA channel
Software characteristic of my system:
1) I have RAID1 (mirror) with use mdadm tool. "raid1" and "md" built as
loadable kernel modules.
2) Over raid created partitions, formated as ext3.
3) kernel version 2.6.18 + xen patch (I have this problem in non XEN
machines)
4) System is Debian etch (latest updates installed, without latest
kernel package).
I don't know where to contol input/output operations... Are Debian
GNU/Linux have the tools for controling it?
This monopoly very high disturbs to server system operation... Are
whether creation of softer sharing of disk input/output over betwen
processes is planned?
Best regards,
Mikhail Konuhov.
software delevoper and system administrator.
mailto: piroman@myconfig.ru
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