[geeks] Solaris 10 zones - interesting blog

[Mike Meredith]

On Wed, 22 Sep 2004 16:01:25 +0000, Lionel Peterson wrote:
> > This guy is running Solaris 10 on a U10 with 512MB RAM.  
> > 
> > He is testing how many zones he can run at once on it.  So far he is
> > up to 54 zones, and is adding more (he started IPs at .200 and just
> > got to .254, so he needs to mess with his scripts).
> 
> That's neat - I wonder if there is a hard limit, becuase I suspect it
> should be able to handle any number of zones, provided he can rig up

I think it's been mentioned that there's a hard limit of 4096 zones. But
perhaps that's just a "don't be silly" (and "here be dragons") limit. Of
course that could be raised later once Sun have had a chance to shake
the bugs out of zones.

I'd expect that the limits would be swap space (there's a minimum of
around 69Mbytes per zone), and how many processes you can run in the
global zone (see 'ps -efZ') given the machine specs.

> everything would swap in and out of local memory, but if all the zones
> are inactive (as it seem they are), the delays caused by the swapping

No zone is entirely inactive ... you've still got the base Solaris
processes running in the zone. Output of 'prstat -Z' :-

ZONEID    NPROC  SIZE   RSS MEMORY      TIME  CPU ZONE
0            92 2771M  860M    86%   0:38:42 8.7% global
1            21   75M   15M   1.5%   0:00:00 0.1% black