Peter Tribble wrote:
The key advantage of using sparse-root is that there's only one OS to manage. With whole-root zones, and other heavier solutions, there's an extra OS image to manage with each virtual system. From an admin perspective, whole-root zones offer no real advantage over xen/vmware, and while I would (and do) run sparse-root zones extensively, I would run Xen or VMware rather than whole-root zones, as they have other capabilities you can leverage.
I think this is incorrect. There is always only a single OS to manage with zones, sparse or whole-root. There is always only a single kernel in memory. In terms of the user-level software management, that has to be done in both the sparse and whole-root cases. The only difference is that some new bits don't have to be copied for sparse, but the pkg metadata must be maintained within the zones in all cases, along with at least a subset of files. There are also other admin advantages for zones over VMs. There is only one kernel sucking up memory. There is massive scalability on a system with zones vs. VMs. Apps run at full speed vs. the overhead of a hypervisor and virtual I/O. You have full observability across all zones using tools like DTrace. Of course VMs have advantages over zones too. It depends on what is important to you. Jerry _______________________________________________ zones-discuss mailing list zones-discuss@opensolaris.org
