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 -- richard -- ZFS and performance consulting http://www.RichardElling.com LISA '11, Boston, MA, December 4-9 _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
