On Mon, Dec 03, 2018 at 02:05:29PM +1100, Erik Christiansen wrote:
> On 03.12.18 00:47, Adam Borowski wrote:
> > On Sun, Dec 02, 2018 at 11:53:39PM +0100, Alessandro Selli wrote:
> > > On 02/12/18 at 17:23, Adam Borowski wrote:
> > > > You'd want to set noatime on every machine
> > > > you control.
> > >
> > >
> > >   Some mail servers and clients do use it to determine if a mail was
> > > read after it arrived.  In this case, it'd be better to have it set on /var.
>
> TL;DR: Use relatime there, as noatime will break mutt.

Hmm...
https://gitlab.com/muttmua/mutt/commit/489a1c394c29e4b12b705b62da413f322406326f
https://github.com/neomutt/neomutt/commit/816095bfdb72caafd8845e8fb28cbc8c6afc114f

> > That's no more. And, let me clarify: atime was used for mail:
> > * only with mbox (Maildir never suffered from this issue)
> > * only on the local machine
> > * only by the shell to say "You have new mail." vs "You have mail."
> > -- not even by the mail client
>
> Not true, according to the on-line manual for my current mutt
> installation:
>
> » Other possible causes of Mutt not detecting new mail in these folders
> are backup tools (updating access times) or filesystems mounted without
> access time update support (for Linux systems, see the relatime
> option).«

In the very post you're responding to, I started with "That's no more.".

> > So the whole effort gave you just a single word in a message, that many
> > people even didn't notice.
> >
> > And, popular local mail clients are already patched to update atime
> > explicitly.
> >
> > Ie, atime for mail is an ex-reason.
>
> A fine assertion, but wiser is to check the facts.

And even wiser to actually change things you don't like. :)

> It would seem then, that noatime will break mutt, but relatime is OK,
> and is now the default. IIUC.

realtime greatly reduces atime writes, but it's still too much. Case in
point: it's the likely culprit for wasting the SD card that started this
thread (on a mostly-read load). And, update frequency of 1/day happens to
match the typical backup schedule, making it ruin snapshots just the same
as strictatime would.

So it's time to kill the nasty thing.


Meow!
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