[gentoo-amd64] Re: Emerge and Tmpfs

[Duncan]

Frank Peters <frank.peters@×××××××.net> posted
20090707103623.17cd03be.frank.peters@×××××××.net, excerpted below, on 
Tue, 07 Jul 2009 10:36:23 -0400:

> After reading through the thread on this list about the benefits of
> mounting PORTAGE_TMPDIR as tmpfs, I decided that I will be doing this
> mount from now on.  My total RAM is 4G, but since I only "emerge world"
> about once per week, I can easily set aside temporarily 2G or more for
> this purpose.
>
> However, after doing some more reading, I find that some people
> recommend mounting tmpfs using the option nr_inodes=1M, while others
> just accept the default value for nr_inodes.
>
> To me, setting maximum inodes to 1M seems a bit high.  Can emerge
> actually generate that many temporary files?  Would it be safer and also
> avoid swapping to set nr_inodes=1M or is the default good enough?.

FWIW, I've never had the slightest issue with the defaults, and that's 
running up to 7+ emerges at once, the way portage's auto-scheduler is 
handling it here, and about that handling it myself based on --tree, 
before that.

However, the mount (1) manpage says the default nr_inodes is half the 
number of physical RAM pages.  At a 4k pgsize, that's 1M for 4 gig 
anyway, and 2M for the 8 gig I'm running, so I /shouldn't/ be running out 
and should be able to lower it.

Personally, I'd just go with the default nr_inodes.  People with 2 gig or 
less of real RAM may need to worry about it, especially if they do a lot 
of parallel makes (tho with 2 gig I'd crimp on parallel makes way more 
than I do, too, so may not have to, but as I've said before, I'm not sure 
of the affect at a gig, someone would have to test and see), but with 4 
gig and a million inodes by default, I think you should be fine.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman