Memory usage of varnish 2.1.3

[Stefan Pommerening]

Hello,

we are using varnish 2.1.3 in a production environment after upgrading 
from varnish 2.0.6.
Varnish is running on several linux blades (suse 10.3) with more than 20 
gb of ram each.

The former configuration using varnish 2.0.6 was not using the -s 
parameter for memory configuration.
Because it seems to be a bit complicated to find documentation exactly 
on this topic for different varnish releases I hope that someone from 
this list can point me in the right direction.

Whilst we had absolutely no memory problems with varnish 2.0.6 the new 
varnish release (2.1.3) seems to behave different than 2.0.6.

Currently (with 2.1.3) varnish is running without -s parameter like 
before (2.0.6). Nevertheless it creates its shared memory file in 
/usr/lib/varnish/<instance>/ and fills up more and more space in the 
filesystem.

For now we are changing the configuration to use "-s malloc,5G" for each 
instance in the beginning and watch memory consumption and varnishstat 
(memory usage and of course nuked objects).

My questions is:
How is varnish behaving if I do NOT use the -s parameter at all (varnish 
2.0.6 compared to 2.1.3 - any differences?)

Thanks in advance,
Stefan