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.

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?