Real memory versus virtual memory: is there a difference?
I'm trying to create very light servers. The following are the main parameters: VMGUARPAGES="4096:9223372036854775807" OOMGUARPAGES="8192:9223372036854775807" PRIVVMPAGES="32768:36864" It boils down to approximatly a 128 MiB machine, right? There is 2 GiB of fysical memory on the hardware node and only a few VE's. At this moment it is a PoC, so the VE is able to burst up to at least 128 MiB. However if a do an aptitude (the VE's are running Debian ) it runs out of memory as seen by the failcnt of privvmpages. So aptitude is memory hungry? Not on a real machine where it runs with just half of the memory! The only explanation I can think of is that in the VE through free the reals memory can be seen, so aptitude doesn't believe the 128 MiB I have given it? Something like that? At least there is an discrepancy between a real machine with low ammounts of memory and a VE with twice as much...