Rich Mingin (PLUG) on 5 Oct 2016 16:52:09 -0700

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Re: [PLUG] Read only USB drive

That's because a hybrid iso that you dd to a USB is still iso9660 filesystem, which is almost always encountered as R/O. It's sorta-kinda-read-only, like a FS that's had all free space used up by DD, or NTFS with all WX perms removed, etc.

On Oct 5, 2016 7:21 PM, "JP Vossen" <> wrote:
On 10/05/2016 11:28 AM, George Zipperlen wrote:
I'm looking for an in-hardware method to make a USB drive read-only.
Either with a built in switch, or, via a small, inexpensive, USB
'sleeve' sitting  between the drive and the USB port.

Use case (1): A larger equivalent to CD-ROM or DVD Write Once Read
Many, for archival backup.
Use case (2): bootable USB sticks
Use case (3): A way to safely distribute data, even their own (!) to
an end user who might inadvertently trash something, or be using an
OS which messes with any file system attached to a USB port.

This probably does not answer all your use cases, and perhaps others on the list can shed more light, but I have found that the so-called "hybrid" ISOs I've "burned" to USB via dd are read only.  The USB stick itself is not but the file system on the stick *is* and while you can reformat the stick to make it writeable again or just dd a new ISO over top of it, I've not found a way to write one used in that way.  I should note I haven't tried either, I've just accidentally reminded myself of the fact when I've booted one then tried to update something.

* for examples

Search on product sites like led me nowhere.
DuckDuckGo (Google) not particularly helpful, mostly junk and
> solutions in software.

DuckDuckGo is not Google, they have their own crawler (  As much as I really want to like them for being local and private, I just can't, because their results have simply never worked for me.  I use, which *is* Google, except proxied with all the Google Evilness removed.  And even THAT doesn't always work, and I sometimes have to actually use Google itself.

I got a sense that USB sticks with a switch do
(used to?) exist.  After a few tries, I have no idea what keywords
would find the 'sleeve' I described, if such a thing exists. Most of
the matches involved software protection dongles; the closest I could
find was expensive forensics hardware, which confirms my belief that
this is technically feasible.

Bergman's Amazon link to a forensics tool was this, and pretty cool, but not cheap.

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