On Monday, September 23, 2013 10:58:19 am Ravi Pokala wrote: > -----Original Message----- > From: Jia-Shiun Li <[email protected]> > Date: Sunday, September 22, 2013 11:22 PM > To: Ravi Pokala <[email protected]> > Cc: "[email protected]" <[email protected]>, > <[email protected]> > Subject: Re: What's the state of AF-4Kn support? > > >On Wed, Sep 18, 2013 at 10:49 PM, Ravi Pokala <[email protected]> wrote: > >> > >>... > > > >CC -hackers. > > > >Thanks for the clarification. Is there any 4Kn HDDs shopping now? I am > >not aware of any. > > Good question. I had the impression that some currently shipping drives > were AF-4Kn, but spot-checking some of the drives listed in > > src/cam/ata/ata_da.c::ada_quirk_table[] > > against their datasheets, suggests that they're AF-512e. So, their being > flagged w/ ADA_Q_4K is "just" a performance optimization. > > >BTW I believe UFS and ZFS have proper design for 4K-sectors, but FreeBSD > >needs some ecosystem connections to get samples early to test, > >incorporate supports and validate for it. Or we will need to wait until > >it appears on market and someone got caught into some kind of bugs. > > Yeah, based on my reading of the code, it looks like the ATACAM layer and > higher (GEOM, filesystems) take the physical block size into account. That > just leaves the bootstrap code. Now that I've taken a second look, it > seems as though at least 'pmbr' only works in terms of 512 bytes. :-(
Yes, the BIOS calls have always only used 512 byte sectors. There would have to be an updated spec for those, and it would be a bit of a PITA to use. I suspect the "right" answer for this on x86 is UEFI. -- John Baldwin _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hardware To unsubscribe, send any mail to "[email protected]"
