Re: [gentoo-user] /var/tmp/portage on tmpfs

[Neil Bothwick]

On 7 January 2015 13:16:03 GMT+00:00, Rich Freeman <rich0@g.o> wrote:
> On Wed, Jan 7, 2015 at 3:36 AM, Neil Bothwick <neil@××××××××××.uk>
> wrote:
> >
> > Personally, I wouldn't bother, there is not that much of a gain when
> > using tmpfs, so if you want to keep all the working files after
> > compilation, the extra overhead and complexity of copying to hard
> disk
> > would make it not worthwhile. Just stick to a spinning disk.
>
> I've found that compiling on tmpfs has a fairly significant
> performance gain, but you'd completely negate it of you copied
> everything to a hard drive anyway.
>
> When you build on a hard drive the filesystem is going to treat all
> those intermediate object files with great care and ensure that they
> aren't lost in the event of a power failure, forcing them to be
> committed to disk within 30 seconds (typically) and blocking IO when
> that happens.  Then a minute later it is going to go and have to
> delete all those files it so carefully committed.
>
> When you build on tmpfs nothing gets written to your filesystem except
> for the final output of the build.  All those intermediate files are
> deleted having never blocked your disk IO.  However, if your goal is
> to actually save them anyway, then you might as well just build on
> disk - moving files doesn't take all that much IO on most filesystems.
>
> If your goal is to create tarballs of the saved builds then you're
> probably still better off building on tmpfs and creating the tarball
> via a hook or something.
>
> --
> Rich

That's why I thought XFS may help. 

Reports of the speed gain from tmpfs are quite mixed, but I do use it myself. 
-- 
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