It would be really nice to have documentation on what features are supported for SATA drives, as well as what the expected defaults are, especially for settings that hdparm currently can't change.
BTW: Is the lack of support for various SATA options a limitation of hdparm, or a limitation of the kernel driver?
Most options now work for SATA drives.
Those that don't (dunno which -- depends on the specific kernel) are due to a combination of libata and hdparm not doing as much as each could do.
Over time, things will continue to improve. But today it's pretty good with the latest kernels.
The -i flag does not work (use -I instead), and will probably get dropped from hdparm at some point.
It doesn't appear that the read-only bit can be set, at least not on a single partition. "hdparm -r /dev/sda1" returns the "readonly = 0 (off)" reply. Repeated usage of hdparm -r results in the same message; the bit is never switched.
Kernel: 2.6.19 (fedora 6) + hdparm 6.6