Questions about ZFS Tuning

Mike Clarke jmc-freebsd2 at
Mon Sep 17 17:22:30 UTC 2012

On Monday 17 September 2012 13:20:14 Jamie Paul Griffin wrote:

> I set zfs.zfs.prefetch_disable=0 because some dmesg line suggested/implied
> it would benefit. I don't recall the exact output now. 

If you look in /var/run/dmesg.boot you should find the message saying "ZFS 
NOTICE: Prefetch is disabled by default if less than 4GB of RAM is present; 
to enable, add "vfs.zfs.prefetch_disable=0" to /boot/loader.conf."

Since you have 2GB RAM then it's best to leave things as they are with 
prefetch disabled.

Mike Clarke

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