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Groups > linux.debian.user > #192494 > unrolled thread

Re: USB key and lost space

Started by"Thomas Schmitt" <scdbackup@gmx.net>
First post2018-02-16 12:10 +0100
Last post2018-02-19 08:40 +0100
Articles 3 — 2 participants

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  Re: USB key and lost space "Thomas Schmitt" <scdbackup@gmx.net> - 2018-02-16 12:10 +0100
    Re: USB key and lost space Rodary Jacques <rodaryj@free.fr> - 2018-02-18 20:50 +0100
      Re: USB key and lost space "Thomas Schmitt" <scdbackup@gmx.net> - 2018-02-19 08:40 +0100

#192494 — Re: USB key and lost space

From"Thomas Schmitt" <scdbackup@gmx.net>
Date2018-02-16 12:10 +0100
SubjectRe: USB key and lost space
Message-ID<vjM3V-8dW-15@gated-at.bofh.it>
Hi,

Rodary Jacques wrote:
> I did subscribe  in april 2016,

The mail header X-Spam-Status in your mail to the list does not contain
the test "LDOSUBSCRIBER". So currently your address rodaryj@free.fr is
not subscribed.

Consider to subscribe again and also to Cc: the debian-user list with
your replies.


> Where am I supposed to find firmware.tar.gz. It may be a very stupid
> question, I was used with .iso  image disks only.

Other people on debian-user probably have more experience with that.
I have to google.
For the current Debian release 9 "stretch" it is probably on
  https://cdimage.debian.org/cdimage/unofficial/non-free/firmware/stretch/current/


I wrote:
> > So use /sbin/fdisk to create partition 3.

> I used fdisk, cfdisk and partitionprobe and it seems my Key is  quite
> useless now

Which ISO image did you put onto the USB stick ?

Let's give current netinst a try:

  $ dd if=debian-9.3.0-amd64-netinst.iso of=/dev/sdc bs=1M
  ...
  $ /sbin/fdisk /dev/sdc
  ...
  Command (m for help): p
  ...
  Device     Boot Start    End Sectors  Size Id Type
  /dev/sdc1  *        0 593919  593920  290M  0 Empty
  /dev/sdc2        3760   4591     832  416K ef EFI (FAT-12/16/32)

  Command (m for help): n
  Partition type
     p   primary (2 primary, 0 extended, 2 free)
     e   extended (container for logical partitions)
  Select (default p): p
  Partition number (3,4, default 3): 3
  First sector (593920-7864318, default 593920): 
  Last sector, +sectors or +size{K,M,G,T,P} (593920-7864318, default 7864318): 

  Created a new partition 3 of type 'Linux' and of size 3.5 GiB.

  Command (m for help): p
  Disk /dev/sdc: 3.8 GiB, 4026531328 bytes, 7864319 sectors
  Units: sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disklabel type: dos
  Disk identifier: 0x0347fd41

  Device     Boot  Start     End Sectors  Size Id Type
  /dev/sdc1  *         0  593919  593920  290M  0 Empty
  /dev/sdc2         3760    4591     832  416K ef EFI (FAT-12/16/32)
  /dev/sdc3       593920 7864318 7270399  3.5G 83 Linux


  Command (m for help): w
  The partition table has been altered.
  Calling ioctl() to re-read partition table.
  Re-reading the partition table failed.: Permission denied

The final error message comes because i did this as normal user, just
having rw-permission to /dev/sdc.
I unplug and replug the USB stick to let the kernel assess the new
partitioning:

  $ ls /dev/sdc*
  /dev/sdc  /dev/sdc1  /dev/sdc2  /dev/sdc3


> I will try dd, very carefully. to erase this new partition I finally
> created, and perhaps come back to you afterwards.

I would just copy the ISO again onto the USB stick base device 
and then run fdisk.


Have a nice day :)

Thomas

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#192620

FromRodary Jacques <rodaryj@free.fr>
Date2018-02-18 20:50 +0100
Message-ID<vkD8e-RX-9@gated-at.bofh.it>
In reply to#192494

[Multipart message — attachments visible in raw view] — view raw

Le vendredi 16 février 2018, 12:03:56 CET Thomas Schmitt a écrit :
> Hi,
> 
> Rodary Jacques wrote:
> > I did subscribe  in april 2016,
> 
> The mail header X-Spam-Status in your mail to the list does not contain
> the test "LDOSUBSCRIBER". So currently your address rodaryj@free.fr is
> not subscribed.
> 
> Consider to subscribe again and also to Cc: the debian-user list with
> your replies.
> 
> 
> > Where am I supposed to find firmware.tar.gz. It may be a very stupid
> > question, I was used with .iso  image disks only.
> 
> Other people on debian-user probably have more experience with that.
> I have to google.
> For the current Debian release 9 "stretch" it is probably on
>   https://cdimage.debian.org/cdimage/unofficial/non-free/firmware/stretch/current/
> 
> 
> I wrote:
> > > So use /sbin/fdisk to create partition 3.
> 
> > I used fdisk, cfdisk and partitionprobe and it seems my Key is  quite
> > useless now
> 
> Which ISO image did you put onto the USB stick ?
> 
> Let's give current netinst a try:
> 
>   $ dd if=debian-9.3.0-amd64-netinst.iso of=/dev/sdc bs=1M
>   ...
>   $ /sbin/fdisk /dev/sdc
>   ...
>   Command (m for help): p
>   ...
>   Device     Boot Start    End Sectors  Size Id Type
>   /dev/sdc1  *        0 593919  593920  290M  0 Empty
>   /dev/sdc2        3760   4591     832  416K ef EFI (FAT-12/16/32)
> 
>   Command (m for help): n
>   Partition type
>      p   primary (2 primary, 0 extended, 2 free)
>      e   extended (container for logical partitions)
>   Select (default p): p
>   Partition number (3,4, default 3): 3
>   First sector (593920-7864318, default 593920): 
>   Last sector, +sectors or +size{K,M,G,T,P} (593920-7864318, default 7864318): 
> 
>   Created a new partition 3 of type 'Linux' and of size 3.5 GiB.
> 
>   Command (m for help): p
>   Disk /dev/sdc: 3.8 GiB, 4026531328 bytes, 7864319 sectors
>   Units: sectors of 1 * 512 = 512 bytes
>   Sector size (logical/physical): 512 bytes / 512 bytes
>   I/O size (minimum/optimal): 512 bytes / 512 bytes
>   Disklabel type: dos
>   Disk identifier: 0x0347fd41
> 
>   Device     Boot  Start     End Sectors  Size Id Type
>   /dev/sdc1  *         0  593919  593920  290M  0 Empty
>   /dev/sdc2         3760    4591     832  416K ef EFI (FAT-12/16/32)
>   /dev/sdc3       593920 7864318 7270399  3.5G 83 Linux
> 
> 
>   Command (m for help): w
>   The partition table has been altered.
>   Calling ioctl() to re-read partition table.
>   Re-reading the partition table failed.: Permission denied
> 
> The final error message comes because i did this as normal user, just
> having rw-permission to /dev/sdc.
> I unplug and replug the USB stick to let the kernel assess the new
> partitioning:
> 
>   $ ls /dev/sdc*
>   /dev/sdc  /dev/sdc1  /dev/sdc2  /dev/sdc3
> 
> 
> > I will try dd, very carefully. to erase this new partition I finally
> > created, and perhaps come back to you afterwards.
> 
> I would just copy the ISO again onto the USB stick base device 
> and then run fdisk.
> 
> 
> Have a nice day :)
> 
> Thomas
Saturday:
	I don't quite know how, but with fdisk, cfdisk, parted,  partx and partprobe I now have a brand new key with 16 GB (or GiB),  the original size, without the iso file, type vfat (rw, nosuid, nodev, relatime, uid=1000, gid=1000, fmask=0022, dmask=0022, codepage=437, iocharset=ascii, shortname=mixed, showexec, utf8, flush,errors=remount-ro, uhelper=udisks2. I have three oher microSDHC to save!
Sunday:	 That was yesterday! Two of the microSDHC cards didn't resist to my assaults. But the one with netinst iso (with the two partitions)  seem to be much harder. 
	Tired of trying (fdisk cfdisk sfdisk parted failed with "read only disk"), I put the card in my camera to format it, successfully. 
	On a Mac, it is now known as "NIKON D7100" and is read-write, as on the camera. But on my Debian and Fedora boxes, if it recognized as such also, it stays read only: 'wipefs /dev/sde' continue to read:
offset               type 

which was the old  situation, mount says "/dev/sde1 on /media/jr/NIKON D7100 type vfat (ro, etc..." which is correct except for the ro! Same with the other tools.
	How can I force the kernel to forget this 'read only' on the disk? Could it be because of the external card reader I use?
	It is not really important, since I can use this card with my mac and to scan documents, but I like to understand.
	Jacques

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#192639

From"Thomas Schmitt" <scdbackup@gmx.net>
Date2018-02-19 08:40 +0100
Message-ID<vkOdj-8if-5@gated-at.bofh.it>
In reply to#192620
Hi,

Rodary Jacques wrote:
> I don't quite know how, but with fdisk, cfdisk, parted, partx and partprobe
> I now have a brand new key with 16 GB (or GiB), the original size, without
> the iso file,
> [...]
> But the one with netinst iso (with the two partitions) seem to be much
> harder.
> [...]
> 'wipefs /dev/sde' continue to read:
> [...]
> 0x8001               iso9660   [filesystem]
>                     LABEL: Debian 9.3.0 amd64 n

Originally you asked:
> > On  several USB keys used for installation (or try of) I copied iso files of
> > more or less  MB, and the remaining space (of 15 or 31MB is inaccessible

This is a different job than removing an installation ISO from a USB stick
or memory card.

To erase the ISO 9660 superblock of debian-9.3.0-amd64-netinst.iso do

  umount /dev/sde1
  dd if=/dev/zero bs=2048 seek=16 count=4 conv=notrunc of=/dev/sde

But first make sure that /dev/sde is indeed the medium you want to erase.
Device names can change on unplug and replug.


I really wonder what the regular use case of wipefs is. Its man page
looks confusing:

   wipefs can erase filesystem , raid or partition-table signatures (magic
   strings) from the specified device to make the signatures invisible for
   libblkid.
   wipefs does not erase the filesystem itself [...]

Removing "signatures" quite surely damages the mountability. It looks like
this tool is intended to create confusion about disk content.


> mount says "/dev/sde1 on /media/jr/NIKON D7100
> type vfat (ro, etc..." which is correct except for the ro!

So partition 1 now marks a block range with a FAT filesystem.

What does a partition editor (not wipefs) say about partitions ?


> How can I force the kernel to forget this 'read only' on the disk?

First you will have to find the reason.

It could be over-smartness because of the ISO 9660 superblock which
is now iprobably valid only if read from the base device.

It could be lack of rw-permission on /dev/sde1.


In worst case you will have to overwrite the first MB and the last MB of
/dev/sde and then partition it again. All filesystem content will become
inaccessible then.

But for now, try to get rid of ISO 9660, unplug, replug, and see what
happens. Especially look at permissions of overall device file
(e.g. /dev/sde) and partition device files (e.g. /dev/sde1).


Have a nice day :)

Thomas

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