slow ZFS on FreeBSD 8.1

Dan Langille dan at
Sun Jan 2 11:33:52 UTC 2011

On 12/31/2010 6:47 PM, Jeremy Chadwick wrote:
> On Sat, Jan 01, 2011 at 10:33:43AM +1100, Peter Jeremy wrote:

>> Based on my experiences at home, I converted my desktop at work to
>> pure ZFS.  The only issues I've run into have been programs that
>> extensively use mmap(2) - which is a known issue with ZFS.
> Is your ZFS root filesystem associated with a pool that's mirrored or
> using raidzX?  What about mismatched /boot content (ZFS vs. UFS)?  What
> about booting into single-user mode?
> indirectly hints at these problems but
> doesn't outright admit them (yet should), so I'm curious to know how
> people have solved them.  Remembering manual "one-offs" for a system
> configured this way is not acceptable (read: highly prone to
> error/mistake).  Is it worth the risk?  Most administrators don't have
> the tolerance for stuff like that in the middle of a system upgrade or
> what not; they should be able to follow exactly what's in the handbook,
> to a tee.
> There's a link to at the bottom of the above Wiki page
> that outlines "the madness" that's required to configure the setup, all
> of which has to be done by hand.  I don't know many administrators who
> are going to tolerate this when deploying numerous machines, especially
> when compounded by the complexities mentioned above.

This basically outlines the reason why I do not use ZFS on root.

Dan Langille -

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