Very low disk performance Highpoint 1820a

[Steven Hartland]

----- Original Message ----- 
From: "Eric Anderson" <anderson at centtech.com>

> Correct - I misread the dd line.  When you are doing the dd, what is 
> your system busy doing?   (top/ps info)

The machine is idle only me doing the test via an ssh session.

> What do you suspect?

I really dont know what it could be driver issue? iirc scott wrote / converted
this one from source direct form highpoint so maybe he could have some
useful imput here.

> Some info from one of my arrays:
> 
> # dd if=/dev/zero of=./testfile bs=64k count=10000
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 3.581413 secs (182989226 bytes/sec)
> 
> (unmount / mount filesystem)
> # dd if=./testfile of=/dev/null bs=64k count=10000
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 6.747707 secs (97123362 bytes/sec)
> 
> # dd if=/dev/da0s1d of=/dev/null bs=64k count=10000
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 11.252226 secs (58242699 bytes/sec)
> 
> Seems like the reads should be faster than the writes..

Hmm just tried the write and I get:
dd if=/dev/zero of=./testfile bs=64k count=10000
10000+0 records in
10000+0 records out
655360000 bytes transferred in 5.237026 secs (125139727 bytes/sec)

Which is 2.5 times quicker than read which is really just not
right.

Issue with /dev/null?

    Steve / K




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