On Sun, 18 Jun 2017, Greg Troxel wrote: > "John D. Baker" <[email protected]> writes: > > > It turns out the 2TB disks for the planned RAID-5 also have 512-byte > > native sectors, not 4K sectors. So no alignment constraints after all. > > Until one fails and the replacement is 4K.
True. > But, I think this is just a matter of using 64 instead of 63 for the > partition start. and then things are lined up adequately. Or not even that. As long as offset and size are a multiple of 8 (or 8 * num_data_disks for a RAID), it will be good enough. I'll proceed as if the disks were 4K anyway. (My habit is to start 512n PeeCee bootable disks at sector 1 and thereafter align to the disklabel-reported cylinder size). If its likely I'll end up replacing one with a 4K disk, I'll start at sector 8 and round up the sizes accordingly. Data-only disks get the default disklabel starting at sector 0.) -- |/"\ John D. Baker, KN5UKS NetBSD Darwin/MacOS X |\ / jdbaker[snail]mylinuxisp[flyspeck]com OpenBSD FreeBSD | X No HTML/proprietary data in email. BSD just sits there and works! |/ \ GPGkeyID: D703 4A7E 479F 63F8 D3F4 BD99 9572 8F23 E4AD 1645
