On Sat, Nov 12, 2011 at 10:08:04AM -0800, Richard Elling wrote: > > On Nov 12, 2011, at 8:31 AM, Pasi Kärkkäinen wrote: > > > On Sat, Nov 12, 2011 at 08:15:31AM -0500, David Magda wrote: > >> On Nov 12, 2011, at 00:55, Richard Elling wrote: > >> > >>> Better than ? > >>> If the disks advertise 512 bytes, the only way around it is with a > >>> whitelist. I would > >>> be rather surprised if Oracle sells 4KB sector disks for Solaris systems? > >> > >> Solaris 10. OpenSolaris. > >> > >> But would it be surprising to use SANs with Solaris? Or perhaps run > >> Solaris under some kind of virtualized environment where the virtual disk > >> has a particular block size? Or maybe SSDs, which tend to > >> read/write/delete in certain block sizes? > >> > >> In these situations simply assuming 512 may slow things down. > >> > >> And if Solaris 11 is going to be around for a decade or so, I'd hazard to > >> guess that 512B sector disks will become less and less prevalent as time > >> goes on. Might as well enable the functionality now, when 4K is rarer, so > >> you have more time to test and tunes things out?rather than later when you > >> can potentially be left scrambling. > >> > >> As Pasi Kärkkäinen mentions, there's not much you can do if the disks lies > >> (just as has been seen with disks that lie about flushing the cache). This > >> is mostly a temporary kludge for legacy's sake. More and more disks will > >> be truthful as times goes on. > >> > > > > Most "4kB"/sector disks already today properly report both the physical > > (4kB) and logical (512b) sector sizes. > > It sounds like *solaris is only checking the logical (512b) sector size, > > not the physical (4kB) sector size.. > > ZFS uses the physical block size. > http://src.illumos.org/source/xref/illumos-gate/usr/src/uts/common/fs/zfs/vdev_disk.c#294 >
Hmm.. so everything should just work? Does some other part of the code use logical block size then, for example to calculate the ashift? Maybe I should read the code :) -- Pasi _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
