Re: [gentoo-amd64] Re: Symlinks vs. Bind mounts.

["Morgan Wesström" <gentoo-amd64@pp.dyndns.biz>]

Duncan wrote:
> Now, if you /really/ want to make a difference in portage's speed, 
> consider pointing PORTAGE_TMPDIR at a tmpfs.  If you've a decent amount 
> of memory, it'll make a HUGE difference, since all the files it normally 
> creates only temporarily in by default, /var/tmp/portage/* will be 
> created in memory (tmpfs) only.  Even with a relatively low amount of 
> memory, say a gig (we're talking amd64 system context here, after all, 
> and a gig has been relatively common since its introduction, not some old 
> 1990s 32-bit x86), where tmpfs may be swapped out in some cases, the 
> shortest lived files should never hit disk (swap in the case of tmpfs) at 
> all.  That's a LOT of extreme-latency hard-disk I/O avoided!!  If you 
> have some serious memory, 2 gig, 4 gig, higher (I have 8 gig), it's even 
> MORE effective, as only the biggest merges will ever hit disk at all, 
> except of course for the initial PORTDIR/DISTDIR operations and the final 
> qmerge to the live filesystem.

This advice caught my attention since I moved my tmp space to Reiserfs 
for performance reasons. My knowledge of tmpfs is limited but I think it 
is a filesystem that uses RAM and can grow and shrink dynamically, 
right? If I follow this advice, what happens when I compile something 
like Open Office which allocates 3-4GB in /var/tmp during compilation 
and I only have 2GB physical RAM in the computer?

Regards
Morgan