On 6 December 2010 22:16, Bruce Cran <br...@cran.org.uk> wrote: > On Mon, Dec 06, 2010 at 09:31:39PM +0100, Ivan Voras wrote: >> For what it's worth, apparently linux has the concept of "physical" >> and "logical" sector sizes (possibly in addition to "stripe size"), >> with physical being 4096 and logical 512, for example: >> >> # hdparm -I /dev/sde | grep size >> Logical Sector size: 512 bytes >> Physical Sector size: 4096 bytes >> device size with M = 1024*1024: 1430799 MBytes >> device size with M = 1000*1000: 1500301 MBytes (1500 GB) > > So do we, except they're both the same for Advanced Format drives:
There is a subtle difference here which may be important. We have the concepts of "sectorsize" and "stripesize". I think camcontrol actually reports logical and physical sector sizes as reported by low-level drivers but currently GEOM names "logical sector size" as "sectorsize" and "physical sector size" as "stripesize". The term "stripesize" can be overloaded to mean both the item in question - 4 KiB physical sector sizes and RAID stripe sizes. I think this situation is bad and that the two meanings should be split. > # camcontrol identify /dev/ada1 > ... > device model WDC WD10EARS-00Z5B1 > ... > sector size logical 512, physical 512, offset 0 Agreed. Some drives lie. _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
