Changing the default for ZFS atime to off?

[Chuck Burns]

On 6/9/2013 5:39 AM, Damien Fleuriot wrote:
> On 8 Jun 2013, at 20:54, "Steven Hartland" <smh at freebsd.org> wrote:
>
>> One of the first changes we make here when installing machines
>> here to changing atime=off on all ZFS pool roots.
>>
>> I know there are a few apps which can rely on atime updates
>> such as qmail and possibly postfix, but those seem like special
>> cases for which admins should enable atime instead of the other
>> way round.
>>
>> This is going to of particular interest for flash based storage
>> which should avoid unnessacary writes to reduce wear, but it will
>> also help improve performance in general.
>>
>> So what do people think is it worth considering changing the
>> default from atime=on to atime=off moving forward?
>>
>> If so what about UFS, same change?
>>
>
> I strongly oppose the change for reasons already raised by many people regarding the mbox file.
>
> Besides, if atime should default to off on 2 filesystems and on on all others, that would definitely create confusion.
>
> Last, I believe it should be the admin's decision to turn atime off, just like it is his decision to turn compression on.
>
> Don't mistake me, we turn atime=off on every box, every filesystem, even on Mac's HFS.
> Yet I believe defaulting it to off is a mistake.
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+1 here.  I, too, usually turn it off, and doing so isn't especially 
difficult.  Changing DEFAULTS is only good when the defaults actually 
break stuff.

-- 
Chuck Burns <break19 at gmail.com>