Re: noatime on ufs2

On 11 Jan 2024, at 7:30, Miroslav Lachman wrote:

> On 11/01/2024 09:54, Tomoaki AOKI wrote:
>> On Thu, 11 Jan 2024 08:36:24 +0100
>> Alexander Leidinger <Alexander@Leidinger.net> wrote:
>
> [..]
>
>>> There's one possibility which nobody talked about yet... changing the
>>> default to noatime at install time in fstab / zfs set.
>>>
>>> I fully agree to not violate POLA by changing the default to noatime in
>>> any FS. I always set noatime everywhere on systems I take care about, no
>>> exceptions (any user visible mail is handled via maildir/IMAP, not
>>> mbox). I haven't made up my mind if it would be a good idea to change
>>> bsdinstall to set noatime (after asking the user about it, and later
>>> maybe offer  the possibility to use relatime in case it gets
>>> implemented). I think it is at least worthwile to discuss this
>>> possibility (including what the default setting of bsdinstall should be
>>> for this option).
>
> [..]
>
>> A different aspect of view.
>> Nowadays, storages are quickly moving from HDD, aka spinning rust, to
>> SSD.
>> And SSD has a risk of sudden-death of wearing out. In ancient days, HDD
>> dies not suddenly and at least some cases admins could have time to
>> replace suspicious drives. But SSD dies basically suddenly.
>>
>> IMHO, this could be a valid reason to violate POLA. In limited use
>> cases, atime is useful, at the cost of amplified write accesses.
>> But in most cases, it doesn't have positive functionality nowadays.
>>
>> Anyway, we should have time to discuss whether it should be done or not
>> until upcoming stable/15 branch. stable/14 is already here and it
>> wouldn't be a good thing to MFC. Only *.0-RELEASE should be the point
>> to introduce this, unlike discussion about vi and ee on forums.
>
> The default values change over time as the needs of people, programs and hardware change. Many values for sysctls changed over time.
> If "noatime" can help people to not trash SSD / SD storage, I can imagine that bsdinstall will detect the storage type (simple guess can be made by diskinfo -v) and offer a "noatime" option that the user can check/uncheck. This option can be pre-selected for flash based storage.
> I don't care defaults for my-self, I can change them, but sane defaults should be beneficial for new users without much background knowledge.
>
> Kind regards
> Miroslav Lachman

I like the idea of an option in bsdinstall, but I don't think it is necessary
to check the storage type.  It could simply default to noatime.

I think we should automatically use noatime on SD card images (where bsdinstall
doesn't get used).

Separately, I think a relatime option would be a good compromise, and I would
probably use it.

		Mike