Tom Metro wrote:
VMware caching I/O wouldn't really explain it, if the underlying file system is still on a Flash device, which in Stephen's scenario it was.
When running natively, reads and writes are going to queue up behind fsync() calls and programs will block. It's unavoidable because flash has terrible write performance.
When running in a VM the VM system acknowledges fsync() calls and returns an "okay" status without actually performing the sync to disk. The virtualized guest will not block until the host blocks. A result of this is that you can get performance that appears to exceed the physical capabilities of the underlying device.
-- Rich P. _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
