From: nospam@needed.invalid   
      
   On Mon, 3/17/2025 9:21 AM, Daniel70 wrote:   
   > On 17/03/2025 10:49 pm, bad sector wrote:   
   >> On 3/11/25 06:52, Daniel70 wrote:   
   >>> Some time ago, I backed up my Laptop's 500GB internal HD to an 2TB   
   external HD using (I forget) ... It might have been 'dd' but I doubt it.   
   >>>   
   >>> However, the 500GB Internals Image took up 500GB on the External (i.e. a   
   byte-by-byte image, even the empty bytes, apparently!).   
   >>>   
   >>> Now, when I look at that External HD using my Win 11 Desk-top, it doesn't   
   'see' anything.   
   >>>   
   >>> Is this because Linux is at a 'Higher'/'deeper' level than Windows can   
   'see'??   
   >>   
   >> I would call that a reasonable observation with reference to the users.   
   >>   
   >>> If I back-up this Win-11 Desktop to the same External HD, is there a   
   possibility that Win-11 will write itself over the Linux Image?? Or is Win-11   
   able to detect that there is 'something' there so will go looking for the next   
   available UNUSED portion    
   of the External HD??   
   >>   
   >> dd if=/dev/sdA of=/somepath/mybackup-2025-03-17.dd bs=16M status=progress   
   >>   
   >> you can also create a partition exactly the same size as the source and   
   then do   
   >>   
   >> dd if=/dev/sdS of=/dev/sdT bs=16M status=progress   
   >>   
   >> I got "bs=16M" from Carlos some time ago, speeds it up a bit.   
   >>   
   >> If you dd'd a partition you can even boot it and use it but remove the   
   source drive before you do because both will have the same UUID. You can also   
   ure a SuperGrub DVD to boot it if you find it difficult. But you can also   
   mount a backup 'file' and    
   look inside it   
   >>   
   >> mount -o loop /somepath/mybackup-2025-03-17.dd /someotherpath   
   >>   
   >> If you ever boot such a copy you need to be careful with UUID's but also   
   with /etc/fstab content since other automounted partitions WILL fail to mount   
   unless the edits are first maid.   
   >>   
   >> It really pays to use removable drive backplane racks, they give you tons   
   of actual physical control that's increasingly being denied users. I just got   
   me an icy-dock model that squeezes 6 ssd's + a dvd into a single 5-1/2 inch   
   external bay and I    
   haven't used ANY fixed internal drives for 3 decades.   
   >>   
   > I have no intention of ever booting from the Back-up, just wanting to save   
   my data .... but thanks for the suggestions. ;-)   
      
   Only you can do the work, Obiwan.   
      
   We can't see what you've done from here.   
      
   I can place a 500GB file on a 2TB partition, and I can   
   analyze it later with "disktype some.file" and see   
   what is inside the file. If what is inside the file   
   resembles a hard drive, disktype will burst forth   
   with a summary of the old disk drive layout.   
      
   If there are file systems inside the file, a user can   
   use a loopback mount, with a byte offset value, and   
   that will allow reading or writing the partition *inside*   
   the 500GB file.   
      
   If the disk had been "dd" cloned to a second disk, then   
   things like "gnome-disks" should see the file system sitting   
   on the 2TB drive. Even disktype can see it (but should not be   
   needed, as the OS does the analysis for us).   
      
      sudo disktype /dev/sdb   
      
   You have all the tools you need, at your disposal, to   
   "determine what is inside a thing".   
      
      Paul   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)