Re: Performance problems with Seagate Barracuda ES.2 harddisks

[Chris Gilbert <chris%dokein.co.uk@localhost>]

Matthias Scheler wrote:
>       Hello,
> 
> I got a HP Proliant ML110 G4 running a NetBSD/amd64 4.99.69 GENERIC kernel.
> I've recently added two Seagate Barracuda ES.2 SATA harddisk. They work
> fine but the filesystem performance is very poor. In the table below
> "wd0" is an older Seagate FB160C4081 harddisk, "wd1" and "wd2"
> are the new harddisks:
> 
>       dd read(*)      dd write(**)    tar(***)
> wd0    74MB/sec       -                4:11min
> wd1   104MB/sec       102MB/sec       14:22min
> wd2   108MB/sec       102MB/sec       14:06min
> 
> dd_read:      dd if=/dev/rwd<n>d of=/dev/null bs=1m count=2048
> dd_write:     dd if=/dev/zero of=/dev/rwd<n>d bs=1m count=2048
> tar:          Extracting the NetBSD 4.0 source tar archives to an empty
>               filesystem with a size of 9 to 10GB. The tar archives are
>               located on a tmpfs filesystem.
> 
> Can anybody explain why "wd1" and "wd2" are so slow? I've used "dkctl"
> to make sure that the write-cache is enabled on all harddisks.

Do you have softdep on wd0 but not on the others?  I vaguely remember
softdep achieves a big gain for extracting source archives.

Also have you tried dd if=/dev/zero of=/file/on/filesystem bs=1m
count=2048.   That should show if file writing is fast or not.

Thanks,
Chris