- New metrics handling. Metrics are now kept in the new
`struct disk'. Busy time is now stored as a timeval, and
transfer count in bytes.
- Storage for disklabels is now dynamically allocated, so that
the size of the disk structure is not machine-dependent.
- Several new functions for attaching and detaching disks, and
handling metrics calculation.
Old-style instrumentation is still supported in drivers that did it before.
However, old-style instrumentation is being deprecated, and will go away
once the userland utilities are updated for the new framework.
For usage and architectural details, see the forthcoming disk(9) manual
page.