On Mon, Aug 13, 2012 at 07:19:50AM +0000, James Harper wrote: > I notice on my system that bcache presents 4K sectors to Linux. This is > causing me problems with Windows on Xen using my PV drivers (problem = > doesn't work). I haven't figured out if it's my PV drivers that don't tell > Windows the right thing, or if Windows just doesn't like 4K sectors. > > Is the 4K sector thing intentional? I assume there is a performance > improvement in doing so.
It is intentional, but it's configurable. It's mainly for devices that don't support < 4k writes; there might also be a performance impact with some SSDs but I'm sure it's slight. You'll need to reformat - pass --block 512 to make-bcache. The backing devices need to be reformatted too, but just rerunning make-bcache won't touch any of the existing data. > > And what would be the performance impact if I just told Windows that it was > dealing with 512 byte sectors (eg fake it)? > > Thanks > > James > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
