Luis, > /sys/block/<disk>/queue/minimum_io_size > > The documentation suggests " For disk drives this is often the > physical block size." > > /sys/block/<disk>/queue/optimal_io_size > > The documentation suggests this is "This is rarely reported for disk > drives." min_io and opt_io are used to key mkfs.xfs' sunit/swidth. So if you're using a hardware RAID, MD, or DM, we'll attempt to align allocations on stripe boundaries. Back when that "rarely reported" blurb was written (2009), we did not have any individual disk drives which reported min_io/opt_io. Reporting those parameters was mostly a storage array thing. These days it's fairly common for both disk drives and SSDs to fill out these fields. > From my review of xfs's mkfs is we essentially use the physical block > size as a default sector size if set, otherwise we use the device's > logical block size if set otherwise xfsprog's default and so 4096. Yep. -- Martin K. Petersen Oracle Linux Engineering
