Bug#593658: default compression=on?

[Ivan Jager <aij+@mrph.org>]

On Thu, Aug 19, 2010 at 09:30:33PM -0400, Brett Dikeman scribbled:
> On Thu, Aug 19, 2010 at 8:55 PM, Tuco <tuco.xyz@gmail.com> wrote:
> 
> > I suggest enabling compression by default when creating new ZFS filesystems.
> 
> I suggest giving the user the option during an install, if ZFS is

I suggest running more benchmarks before suggesting the default
should be changed. :) The benchmark in question was measuring the
time and energy used while copying a file already on the same
filesystem, on some unspecified laptop. Do we really want to
optimize for copying files on an otherwise idle computer with a
slow disk while completely ignoring any effects this might have
on desktops, servers, or computers that are actually doing
something?

BTW, I expect deduplication would have a much more drastic effect
on this benchmark. We should turn it on by default. /s
 
> It'd probably be worth talking to the ZFS developers to find out why
> compression isn't enabled by default in Solaris/OpenSolaris.  They
> probably had some logic behind it, and it might be relevant.

My guess would be that they are optimizing for computers that
actually compute things. Another reason might be that if the
filesystem explodes it is easier to recover uncompressed files,
although I get the feeling ZFS developers like to think that
would never be necessary. But, yeah, it's probably worth checking
with them before changing the default.

Ivan