why is RW-mounted SD card treated as mounted RO?

[Robert P. J. Day]

On Fri, 14 May 2010, Kent Borg wrote:

> Robert P. J. Day wrote:
> > $ mount
> > ... snip ...
> > /dev/sdb1 on /media/6458-0D98 type vfat
> > (rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,flush)
> > $
> >
> >   that normally suggests that the card is mounted read/write, but if i
> > "cd" onto the card and attempt to make any changes, i get:
> >
> > $ touch fred
> > touch: cannot touch `fred': Read-only file system
>
> Last time I saw something like that it was because I was trying to mount
> a Mac-formated Ipod and the journal was not supported by Linux.
>
> Are there any interesting data in /var/log/messages? (The Ipod did put
> out an error that I could Google...)

  the relevant lines from /var/log/messages:

May 14 16:01:37 lynx kernel: [103132.412402] sd 8:0:0:0: [sdb] 501248
512-byte logical blocks: (256 MB/244 MiB)
May 14 16:01:37 lynx kernel: [103132.414310] sd 8:0:0:0: [sdb] Write
Protect is off
May 14 16:01:37 lynx kernel: [103132.422458]  sdb: sdb1
May 14 16:01:37 lynx kernel: [103132.427613] sd 8:0:0:0: [sdb]
Attached SCSI removable disk

note that "Write Protect is off."  so being told that it's a read-only
file system is certainly puzzling.

rday

-- 

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Robert P. J. Day                               Waterloo, Ontario, CANADA

            Linux Consulting, Training and Kernel Pedantry.

Web page:                                          http://crashcourse.ca
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