Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #286643

Re: Initial state of drive found by xorriso.

Show all headers | View raw

From: "Thomas Schmitt" <scdbackup@gmx.net>
Date: Thu, 14 May 2026 10:01:05 +0200
> A CD/DVD/BD burner, a USB stick, a hard disk ?

HDD connected by USB.  

> How much storage capacity does it offer ?

Nominally 500 GB; significantly larger than other drives in the 
system.

Rebooted since composing the orginal message.  Currently the drive is sdf.
Image from Gparted here.  https://easthope.ca/LaCieGparted.jpg

> The emerging ISO would occupy 2258784 "CD data sectors" of 2048 bytes
> each (4412 MiB)) whereas the medium offers only 951368 * 2048 bytes
> of remaining capacity (1868 MiB).

> This is quite surely not the drive which only offers 1868 MiB of free
> space.
> That drive was "blank" or "appendable", or else xorriso should not
> have reached the point where it complains about the lack of space.
> 
> /dev/sdd is probably a USB stick or a hard disk. This kind of drive
> is considered by xorriso as holding an overwritable medium.
> So this statement from man xorriso applies:
> 
> Closed is the state of DVD-ROM media and of multi-session media which
> were written with command -close on. [...]
> Overwritable media assume this state [...] if they contain
> unrecognizable data in the first 32 data blocks.
> 
> Obviously your /dev/sdd contains non-zero data in these 64 KiB, but
> these data do not indicate the presence of an ISO 9660 filesystem.
> Considering such a "medium" as closed is a safety precaution against
> destroying data without knowing what they might mean.
> 
> Yes. After being very very sure (*) that /dev/sdd is the right drive
> address, do
> 
>   xorriso -outdev stdio:/dev/sdd -blank as_needed
> 
> xorriso will then write 64 KiB of zeros to the beginning of the drive,
> which invalidates a possible partition table and might invalidate
> a possible other filesystem which is currently on /dev/sdd.

I contemplate Gparted deleting the FAT part. Any disadvantage there?

A twin of this drive was deployed more than a year ago.  Don't 
remember how I initialized it.  =8~/

> -----------------------------------------------------------------------
> (*)
> Excluding any other drive from being overwritten is of course crucial.
> 
> With USB sticks i use such opportunities to test xorriso-dd-target
> with its plug-in identification of USB drives:
> 
>   xorriso-dd-target -with_sudo -plug_test
> 
> This run will ask you to first have the drive unplugged, press Enter,
> then plug in the drive, and press Enter again.
> The result will be something like
>   sdd : YES : usb+ has_vfat+ : INTENSO USB
> or
>   sdd : NO  : usb+ ... has_ext2- : INTENSO USB
> 
> The evaluation "YES" or "NO" is not decisive in this case, because you
> want to overwrite the device in any case.
> Decisive is the device address "sdd", which belongs to the drive that
> was plugged in during the xorriso-dd-target run.

Thanks.  =8~) The Gparted graphical presentation also may help me 
avoid blunders.

Thx,                    ... P.

-- 
mobile:  +1 778 951 5147
VoIP:    +1 778 508 0020
Bcc: peter at e a s t h o p e dot c a
projects: en.wikibooks.org/wiki/User:PeterEasthope

Back to linux.debian.user | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Initial state of drive found by xorriso. peter@easthope.ca - 2026-05-14 01:40 +0200
  Re: Initial state of drive found by xorriso. peter@easthope.ca - 2026-05-14 17:50 +0200
    Re: Initial state of drive found by xorriso. nwe <nwe@gitcoding.net> - 2026-05-14 18:30 +0200

csiph-web