How to restore a USB drive converted to bootable

[Lowell Gilbert]

"William A. Mahaffey III" <wam at hiwaay.net> writes:

> On 05/02/15 09:06, Lowell Gilbert wrote:
>> "William A. Mahaffey III" <wam at hiwaay.net> writes:
>>
>>> I am about to do some OS installs (NetBSD & OpenBSD, as it happens) on
>>> boxen under construction. I would also like to use UBCD on a flash
>>> drive to memcheck those boxen prior to installation. If I prep a USB
>>> thumb drive as either a bootable UBCD drive or an over-the-WWW
>>> installer, I wipe out the drive for its original use. Is there a way
>>> to restore the drive back to its original functionality if I wanted to
>> Is "wipe the drive and reformat" what you need to hear, or do you have
>> more requirements that you haven't made clear?
>>
>
>
> Wipe & reformat, preferably from CLI under FBSD 9.3R-p13 for
> convenience, is what I'm after. Clearly creating a bootable UBCD or
> installer will wipe out whatever was
> there before, so I just want to get back to 'virgin' USB drive.

[TL;DR version: do
       newfs_msdos -F 32 /dev/da{x}
 and you'll probably be happy.
]

That's still not very specific. Thumb drives come from the factory with
a number of different configurations. If you want the one your specific
device started with, you need to back it up (dd(1) will do fine) before
writing over it.

Otherwise, it's just like any other disk; format it any way you like. If
you want an MBR, use fdisk(8); if you want a GPT table, use gpart(8); if
you don't need either, stick with the raw device.

Create a new filesystem. If you want it to be FAT32, you can do that
with newfs_msdos(8). I don't remember offhand how to do VFAT, but that's
an option if you want. If you're only going to use the drive with BSD
systems, I'd recommend you use newfs(8) rather than FAT filesystems --
this won't match anything you might have gotten from a store, but you
won't notice any difference (aside from better performance).