> But there are hacks to get around this, and it's mostly an issue with POS rube goldberg machine web stacks like Apache/mod_php. It's a common technique used

> But there are hacks to get around this, and it's mostly an issue with POS rube goldberg machine web stacks like Apache/mod_php. It's a common technique used by a lot of virtual machines and memory management code to get a large contiguous region of address space to work with (most JVMs work this way, SBCL does too). I'm not exactly sure why Xen can handle overcommit fine and Virtuozzo can't, the latter does need a custom kernel so in principle they have access to all the low-level virtual memory stuff.