Re: USB drive mounted Read-only; what to do ?
On Fri 19 Dec 2014 at 11:47:38 +0100, Frédéric Marchal wrote:
> 2014-12-19 11:28 GMT+01:00 Renaud OLGIATI <renaud@olgiati-in-paraguay.org>:
> > On Fri, 19 Dec 2014 10:15:32 +0000
> > Brian <ad44@cityscape.co.uk> wrote:
> >
> >> > I plug in a USB pen drive, and launch dd to copy an iso image.
> >> > # dd bs=4M if=debian-live-7.6.0-amd64-rescue.iso of=/dev/sdi && sync
> >> > dd: opening `/dev/sdi': Read-only file system
> >
> >> It contains am ISO9660 file system which, by design, is read-only.
> >
> > No, when I launch dd it contains a FAT32 file system.
> >
> >> > Is there a way to force it to mount read-write ?
> >
> >> Nothing is mounted during the reading and writing process.
> >
> > Then why does dd complain, and refuse to run ?
>
> There is nothing to mount here as that dd command is writing to the
> whole disk (of=/dev/sdi). It bypasses the partition table and the file
> system.
>
> Do you run the command as root? A user can't write to a device
> (imagine anybody could run dd if=/dev/zero of=/dev/sda where sda is a
> system disk).
A user can write to a USB stick on Wheezy (which seems reasonable to me)
but not on testing/unstable. Not that that has anything to do with the
OP's problem.
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