Re: Error message from GParted, means what?

[Richard Owlett <rowlett@cloud85.net>]

On 11/27/2016 3:15 AM, Pascal Hambourg wrote:
> Le 26/11/2016 à 23:42, Richard Owlett a écrit :
> > I've been getting a strange error messages when looking at some
> > 8 GB
> > flash drives from different manufacturers purchased months apart.
> >
> > There is a title bar at top saying "Libparted Warning (as
> > superuser).
> > The body of the message box has:
> >   1. an Exclamation point surrounded by orange and yellow
> > triangle.
> >   2. a message text saying "The driver descriptor says the
> > physical block
> >      size is 2048 bytes, but Linux says it is 512 bytes.
> >   3. There are two buttons present.
> >      One saying "Cancel"
> >      The other saying "Ignore"
>
> I have seen this behaviour when running parted on a USB flash
> drive containing a Debian installer ISOhybrid x86 image which
> seems to combine a DOS partitition table, an Apple Mac partition
> table, a GPT partition table and an ISO 9660 header. I guess the
> 2048-byte block size is set to match the sector size of optical
> media.
>
> I have found that historically partitioning tools based on
> libparted (parted, gparted, partman [Debian installer]) did not
> handle well this non-standard format. The parted version in
> Wheezy just could not read it.
>
> Another problem I observed is that erasing the partition table
> does not erase the ISO 9660 header, and programs based on
> libblkid (udev, desktop environment file managers) still find it
> and wrongly apply the identifier string in it to label the drive.
>
> Before reusing a drive which had contained an ISO image, I advise
> to erase any metadata with wipefs.

*THANK YOU*  <MASSIVE GRIN>!
I think you may have cleared up several hard to isolate problems.
It may be an interesting exercise, before first use of a brand 
new flash drive, to examine it via Gparted and "wipefs /dev/sdX"

Yesterday I had purchased a blister pack of four 8GB that were on 
clearance at a local office supply store [labeled "Lexar by 
Micron" "Jumpdrive S50" USB 2.0].

One was used without any apparent problem to be the source for 2 
preseed.cfg files. I did installs with each which ran as expected.

One was plugged in before I ran a script to prepare a file that 
would later be written to the flash drive. There was some [not 
yet identified] problem with the script indicated by flashing of 
drive activity light. That was the drive that prompted my post.

After reading your message I examined the other two drives.
  "wipefs /dev/sdb" reported a dos partition table at 0x1fe.
  Gparted showed:
    1st drive
      4.03 MiB unallocated
      7.45 GiB FAT32 (1.91 MiB used) (no Flags set)
    2nd drive
      7.46 GiB FAT32 (4.03 MiB used) (lba Flags set)

One of them had been plugged into one of my machines yesterday. 
Which and what action taken - unknown.

I assume that running "wipefs --all --force /dev/sdb" followed by 
using Gparted to create a partition table followed by 
partitioning will make all Debian tools "happy".

Thank you.