zlacker

>>hugodu+(OP)
I really want VM's to integrate 'smarter' with the host.

For example, if I'm running 5 VM's, there is a good chance that many of the pages are identical. Not only do I want those pages to be deduplicated, but I want them to be zero-copy (ie. not deduplicated after-the-fact by some daemon).

To do that, the guest block cache needs to be integrated with the host block-cache, so that whenever some guest application tries to map data from disk, the host notices that another virtual machine has already caused this data to be loaded, so we can just map the same page of already loaded data into the VM that is asking.

>>london+f4
Are you sure you're not thinking "copy on write" rather than "zero copy"? The latter implies you can predict in advance which pages will be the same forever...

>>andrew+Nd
The pages would be copy-on-write, but since this would mostly be for code pages, they would never be written, and therefore never copied.

By 'zero copy', I mean that when a guest tries to read a page, if another guest has that page in RAM, then no copy operation is done to get it into the memory space of the 2nd guest.