Thinking of using ZFS/FBSD for a backup system

[Kris Kennaway]

Ollivier Robert wrote:
> According to Kris Kennaway:
>> (ports-i386:~)> cat /boot/loader.conf
>> vfs.zfs.prefetch_disable=1
>> vm.kmem_size=1572864000
> 
> Hvae you tried w/o the prefetch_disable tunable?

I have not done careful measurements, but casual observation suggests 
that on my workloads I get better performance without prefetch.  I have 
a pair of mirrored disks on an amr, and my workload is quite 
random-access so prefetching just introduces latencies and wastes 
already-saturated disk bandwidth.  With more disks or a different 
workload I would expect different performance characteristics.

Kris