Re: [partial resolution] Re: Problem withj dd

[Richard Owlett]

On 02/21/2018 12:39 PM, Richard Owlett wrote:

On 02/21/2018 12:22 PM, Reco wrote:

Hi.

On Wed, Feb 21, 2018 at 11:39:42AM -0600, Richard Owlett wrote:

I've downloaded the netinst iso with intention of copying it to a flash
drive. I've done it before without problem.

root@debian-jan13:/home/richard# dd bs=64k 
if=/home/richard/Downloads/debian-9.3.0-amd64-netinst.iso of=/dev/sdc

dd: failed to open '/dev/sdc': No medium found
root@debian-jan13:/home/richard# ls /dev/sdc
/dev/sdc
root@debian-jan13:/home/richard#


What's happening?
[or perhaps "What have I forgotten?"]


That's a legitimate question, but a better one(s) would be:

[snip]

5) Can one be really sure that "/dev/sdc" is a flash drive?

Reco




A variation of the "device does not always get the same /dev/??? 
designation". I've got another problem. After giving dd the correct 
destination the install did not go as expected. I've an idea of what's 
wrong but I need to run some tests. More later. Thanks




Found it. An intermittent hardware problem. IOW not really a Debian problem

Re: Re: [partial resolution] Re: Problem withj dd

[Andy Smith]

Hi Jacques,

On Fri, Feb 23, 2018 at 02:46:47AM +0100, Rodary Jacques wrote:
> 1/ No the same removable device doesn't always receive the same /dev/sdX.If 
> you unmount  it ( umount /dev/sdX) and plug it again, it can be called 
> /dev/sdY (I suppose the kernel keeps tne name in memory for some time). 

You might find it more convenient to use the device aliases in the
/dev/disk/by-* directories as these can be based on some persistent
property of your removable device such as its label, serial number,
or which port it is plugged into etc.

Cheers,
Andy

Re: Re: [partial resolution] Re: Problem withj dd

[Rodary Jacques]

1/ No the same removable device doesn't always receive the same /dev/sdX.If you 
unmount  it ( umount /dev/sdX) and plug it again, it can be called /dev/sdY (I 
suppose the kernel keeps tne name in memory for some time). 
2/ use "mount" without arguments., plug your flash drive and run "mount" again: 
the new /dev/sdX  (or /dev/sdXn) is your drive (or mounted partition). Unmount 
it with "umount /dev/sdX(n)" and run dd with  "dd if=input-image of=/dev/sdX 
[options]" without the partition number if there was one. All this as root of 
course.
Good luck. Jacques

Re: [partial resolution] Re: Problem withj dd

[Brian]

On Thu 22 Feb 2018 at 06:45:47 +0300, Abdullah Ramazanoglu wrote:

> On Wed, 21 Feb 2018 12:39:28 -0600
> Richard Owlett  wrote:
> > On 02/21/2018 12:22 PM, Reco wrote:
> > > On Wed, Feb 21, 2018 at 11:39:42AM -0600, Richard Owlett wrote:  
> 
> > A variation of the "device does not always get the same /dev/??? 
> > designation".
> 
> You can find out what device it is mapped to from dmesg output.

I get:

  dmesg: read kernel buffer failed: Operation not permitted

Since dd has to be used as the superuser I suppose an extra command as
root is neither here nor there. OTOH, 'lsblk' works nicely for a user.

-- 
Brian.