Re: What's the state of AF-4Kn support?
Jia-Shiun Li <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.hardware |
|---|---|
| Message-ID | <CAHNYxxMZC7cw7TNBJMZewe3ABAS0S6Xaz+uDh2E_YbfP0fa2Pg@mail.gmail.com> |
On Sat, Sep 14, 2013 at 3:14 PM, Ravi Pokala <[email protected]> wrote: > What does 4Kn support look like in -HEAD? I know UFS's defaults (32KB > blocks / 4KB fragments) are 4Kn-friendly, and that `gpart' handles > alignment properly. What about direct drive I/O (i.e. do the device > drivers do the proper read/modify/write stuff if you try to write a > partial block)? What about the bootstrap code; I've looked at pmbr.s and > gptboot.c, and it's not clear if they DTRT in the face of 4Kn drives. RMW is done in HDD firmware. The HDDs still do 512b-sector I/Os, only giving additional hint that physically it is 4K and if aligned performance would be better. Functionally speaking there is no difference from not-so-advanced-format (if cost-down is an advance) HDDs. Jia-Shiun. _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hardware To unsubscribe, send any mail to "[email protected]"