On 2026/03/02 16:22, Crystal Kolipe wrote:
> On Mon, Mar 02, 2026 at 10:10:39AM -0500, Eric Radman wrote:
> > For systems with more than one disk, the order of sd(4) devices make it
> > very likely that autoinstall will destroy a volume intended only for
> > data.  In the following example, sd1 (at sdmmc0) is the intended target,
> > but if an NVMe or a second SATA devices is added, the correct choice
> > will become sd2:
> > 
> >     sd0: ATA, ST5000LM000-2U81, 0001 naa.5000c500eb875982 (4657.5G)
> >     sd1: Samsung, BJTD4R, 0000  (29.1G)
> > 
> > To guard against this, you really have to reboot, double-check the
> > device assignments, then reboot again to begin the install.
> 
> Why do you need to reboot and double check the assignments?  The installer
> displays the disk type, model number, capacity.
> 
> > The attached patch allows autoinstall to sort disks based on expected
> > size.  Devices between 1 and 1000GB are presented as the default choice:
> > 
> > Select root disk by size? (range in GB) [1-1000]
> > Available disks are: sd0 sd1 sd2 sd3.
> > Which disk is the root disk? ('?' for details) [sd2] ?
> >     sd0: VirtIO, Block Device  (0.5G)
> >     sd1: VirtIO, Block Device  (4096.0G)
> >     sd2: VirtIO, Block Device  (5.0G)
> >     sd3: VirtIO, Block Device  (10.0G)
> > 
> > As before, any disk may be selected, but this provides a mechanism for
> > picking a plausible install target.
> 
> I don't see any usefulness in this whatsoever.

it only helps autoinstall (in relatively complicated scenarios).

> Also, the values seem to be fairly arbitrary.  USB flash drives with less than
> 1 Gb of capacity are increasingly difficult to find, so it's entirely
> plausible that a 4 Gb or 8 Gb drive is the install media.  Drives of this size
> are also practical install targets, so how can you make a resonable assumption
> just based on size alone?

you might be able to do that if you have more information about the
disks you're likely to see, but, if you know that then you probably know
the order they're attached too..

bsd.rd autoinstall is not really for complicated scenarios, I think
this is beyond the scope of what it's meant for.