Defaults in 10.0 ZFS through bsdinstall

[Warren Block]

On Wed, 20 Nov 2013, Julian Elischer wrote:

> On 11/20/13, 3:35 PM, Steven Hartland wrote:
>> ----- Original Message ----- From: "Matthew Ahrens" <mahrens at delphix.com>
>>>> I noticed a couple of things with the ZFS defaults that result from
>>>> using the new installer in 10.0-BETA3.
>>>> 
>>>> One, atime is turned off everywhere by default.  There was a thread on
>>>> this list on June 8 with a subject of 'Changing the default for ZFS
>>>> atime to off?', and from what I can tell the idea of turning off atime
>>>> by default was not a popular one.
>>>> 
>>>> 
>>> It would be a pity if people compared ZFS on FreeBSD vs UFS on FreeBSD
>>> (using the installer's defaults) and came to the conclusion that "Mail
>>> programs don't work on ZFS on FreeBSD, use UFS instead."  I think it's 
>>> well
>>> known that there are performance differences between ZFS and UFS, 
>>> depending
>>> on your workload.  If you choose defaults that cause there to be
>>> correctness differences, that could be detrimental.
>> 
>> It would also be a pitty if users came to conclusion not to use ZFS because
>> it wears their SSD's out much quicker than UFS does or performs much
>> worse.
>> 
>> Having a sensible default that's correctly messaged is something to
>> be commended not discouraged because its not the tradition and for
>> those that don't bother reading they may have issues as that could
>> be said for any option.
>> 
>> Its also not something that can't be changed in seconds either, so the
>> suggestion of /var with it enabled so default mail installs work
>> as normal and for those that choose to install mail folders else
>> where they need to read and learn, instead of peanalising every single
>> user gets my vote.
>
> I think the installer should make a point of asking the user what they need..
> then they cannot complain if they chose something they don't want.

How about adding a test and warning to /etc/mail/Makefile and the ports 
affected?  Or maybe it can be done in a single place with mailwrapper.

In general, it seems like the applications that depend on atime (or any 
feature, really) should be responsible for detecting that it is enabled.