Re: [exim-dev] Old topic again: Option to avoid fsync()?

> I try to avoid r/w contention by using full data journalling with external
> journals, which are on physically different (and hopefully faster) HDDs. I
> believe this is good practice for synchronous I/O like mail and NFS.

There is a bunch things you can do for _regular operation_. But disks can
fail by getting ridiculous slow, networks can lose or destroy packets,
name servers can fail, then of course there are attacks and whatever
else... and you end up with a queue.

Disable fsync() for a couple minutes and people have their mail. Enable
it again and everything is fine.

> For real psychopathic I-don't-care-about-my-data cases you can always use
> tmpfs..

Right, but that may either cause swapping or I have a very limited queue.
Running the system on real disks, but without fsync(), means data will
either be written lazy, or not at all. It's nicely in between tmpfs
and fsync().

Do you vote for or against having an option to disable fsync()?

Michael