On Mon, Jun 20, 2011 at 08:30:40PM -0400, Kenneth R Westerback wrote: > I committed a fix to fdisk(8) today to un-break the -i and -e options > on 4096-byte devices. To make a long story short, it had been working > accidentally until I committed a 4.9 change to fdisk(8) to make > it pay attention to the errors returned from MBR_read(). > > However this has raised once more concerns about what is going to > happen when 4096-byte sector devices become common, then the norm, > and then the smallest disks available. > > There has been a lot of work done in the last few years to de-couple > the internal kernel view of a disk (a series of 512 byte blocks) > and the 'real world' view of potentially different sector size > devices. With seemless translation being done behind the scenes. > > However, as today has shown, there may well be further unreconstructed > code making invalid assumptions or currently silently working > accidentally and waiting for the day when it can blow up your > machine. > > So if you have such a device (disks >3TB are your best bet) I would > be very interested in hearing how hard you have to work to break > something. Of course the clever can also create vnd's with such > large sectors but actual hardware is more convincing. > > Various filesystems (supported ones only please!), utilities such as > fdisk, disklabel, newfs, fsck, dump, restore, etc. Anything which > may do any serious disk i/o or is suspected of attempting raw, low > level i/o.
It just occurred to me that softraid crypto would benefit quite a bit from 4096 byte sectors. And... we can use softraid to force 4096 byte sectors pretty trivially so it can be used a test harness as well in lieu of 3096 byte sector disks. > > .... Ken
