>>> Hm, dd if=/dev/zero of=/dev/sdb bs=1M count=1
>>
>> Yes, that will clear it out. But what file system is customarily on
>a new
>> 16G microsd card? And does that fs really need everything cleared
>out?
>
>No, that will not wipe the GPT or it's backup.

Ah, but zero the whole disk and it will

dd if=/dev/zero of=/dev/sdb bs=1M

It'll use one write cycle on the media.

Simon


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