RELENG_7 heavy disk = system crawls

Dieter freebsd at
Sun Aug 9 04:06:55 UTC 2009

> I can dd if=/dev/ad[n].eli of=/dev/null bs=1m and use 75% system
> all in geli, 27% disk busy, 20MiB/sec. Interface was slower but
> reasonable.

I think I understand now.  You're doing encryption in the kernel,
which eats a lot of cpu, and nice only affects userland.  So yeah
cpu is a significant part of your problem.

> I'm not sure yet how to isolate cpu from i/o under my geli+zfs
> setup. I think they're mated together.


> It's just that this workload has really put the screws to things
> and I don't see a way out. I'd like to deploy geli+zfs everywhere
> but if I can't login remotely because some user has it busied out
> on something I've no knobs to control, umm, yeah :)

Do you *need* geli+zfs ?  If so, you could see if there are any
hardware crypto accellerators with FreeBSD support, or throw
lots of cpu (e.g. phenom2 x4) at it.

> As to your i/o thing, I think back in RELENG_4 that if all the
> spindles were on the same pata controller/interrupt, monopolistic
> loads could occur.

atapci0: <nVidia nForce CK804 UDMA133 controller> port 0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xe000-0xe00f at device 6.0 on pci0
atapci1: <nVidia nForce CK804 SATA300 controller> port 0x9f0-0x9f7,0xbf0-0xbf3,0x970-0x977,0xb70-0xb73,0xcc00-0xcc0f mem 0xfebfb000-0xfebfbfff irq 21 at device 7.0 on pci0
atapci2: <nVidia nForce CK804 SATA300 controller> port 0x9e0-0x9e7,0xbe0-0xbe3,0x960-0x967,0xb60-0xb63,0xb800-0xb80f mem 0xfebfa000-0xfebfafff irq 22 at device 8.0 on pci0
atapci3: <JMicron JMB363 SATA300 controller> port 0x8c00-0x8c07,0x8800-0x8803,0x8400-0x8407,0x8000-0x8003,0x7c00-0x7c0f mem 0xfe9fe000-0xfe9fffff irq 17 at device 0.0 on pci3
atapci4: <SiI SiI 3132 SATA300 controller> port 0x6c00-0x6c7f mem 0xfe6ff000-0xfe6ff07f,0xfe6f8000-0xfe6fbfff irq 16 at device 0.0 on pci4
atapci5: <JMicron JMB363 SATA300 controller> port 0x4c00-0x4c07,0x4800-0x4803,0x4400-0x4407,0x4000-0x4003,0x3c00-0x3c0f mem 0xfe3fe000-0xfe3fffff irq 18 at device 0.0 on pci6

The nForce pata controller doesn't list an irq, seems odd?

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