From: Jeff@invalid.invalid   
      
   On 03/09/2025 14:47, Paul wrote:   
   > On Wed, 9/3/2025 3:05 AM, Jeff Layman wrote:   
   >> On 02/09/2025 23:46, Lawrence D’Oliveiro wrote:   
   >>> On Tue, 2 Sep 2025 16:26:18 +0100, Jeff Layman wrote:   
   >>>   
   >>>> ... but when I plugged in the USB stick and tried "Restore" it   
   >>>> reported that there were no backups! I thought the whole point of   
   >>>> having a backup is that it would be easy to restore to a new HD if   
   >>>> the old one had failed.   
   >>>   
   >>> This is why you need to test your backup system by doing an actual   
   >>> restore. Without that, you don’t actually have a backup system.   
   >>   
   >> I agree. When I started using Deja Dup (not "Deja vu"!!!) I tried a restore   
   to a temporary folder on the hard drive and it worked perfectly. I've since   
   tried restoring the odd file and folder just to check. All went without   
   problem. Out of interest, I    
   just tried the same thing on my current laptop with the backup I created   
   yesterday. Deja Dup found the backup on the USB stick immediately, and asked   
   what I wanted restored and where. I created a folder called "Restorecheck" and   
   "restored" a folder to it    
   without problem.   
   >>   
   >> So when I run Deja Dup on the other laptop, why does it not see the backup   
   on the USB stick?   
   >>   
   >   
   > A quick Google   
   >   
   >      “Backup Failed”: Could not restore '~/.cache/deja-dup/metadata'   
   >   
   > Maybe have a look in there and see what "metadata" exists, per laptop ?   
   >   
   > Perhaps it cheats, checks the metadata, then it sniffs some storage   
   identifier on the USB stick   
   > and realizes the USB stick has been mounted on the system before.   
   >   
   > The other laptop, might require a brute-force search to find such things.   
   >   
   > On Windows, we would use Process Monitor, and CreateFile/ReadFile/WriteFile   
   > of a program execution session would be recorded for us. On Linux   
   > this might be "strace" or "truss", and what is recorded there, is mostly   
   > path execution without a lot of other event types being recorded. (At one   
   time,   
   > the recorded paths had string length limitations, and software had to be   
   > staged in a way that the pathname would not be too long.) Back in   
   > my Unix days, this was frequently sufficient to develop a breadcrumb and   
   > a theory, how a program worked. But over the years, such traces have so   
   > much noise in them, it's a needle in a haystack. We would sometimes use   
   > this on X11 applications, to see what order they were evaluating potential   
   > preference files. There might be thirty "file not found" entries, which   
   > is the program methodically checking for preferences. Such an approach does   
   > not work well on multi-process executables -- an strace on Firefox might   
   > not be tracing the process that is doing something naughty. When programs   
   > like that were invented, multi-process and named pipes were not exactly   
   > what they were designed for.   
   >   
   > Debuggers can also give access to such information, but having a lightweight   
   > tracer is just so much easier (no learning curve).   
   >   
   > *******   
   >   
   > https://man.archlinux.org/man/duplicity.1.en   
   >   
   >     --metadata-sync-mode mode   
   >      This option defaults to 'partial', but you can set it to 'full'   
   >   
   >      Use 'partial' to avoid syncing metadata for backup chains that   
   >      you are not going to use. This saves time when restoring for the   
   >      first time, and lets you restore an old backup that was encrypted   
   >      with a different passphrase by supplying only the target passphrase.   
   >   
   >      Use 'full' to sync metadata for all backup chains on the remote.   
   >   
   > That implies there is some sort of expectation in terms of   
   > what Master, restores what Slave ? Maybe you weren't supposed   
   > to take the USB stick over there ?   
   >   
   > This seems to be hiding the details   
   >   
   >      https://apps.gnome.org/DejaDup/   
   >   
   >         "Back up to the cloud, a network server, or a local drive"   
   >   
   > Perhaps not all options, have the same restore capabilities ?   
   > Maybe your NAS would be a good staging area (a consistent identifier   
   > on both machines), but then I'm not sure how the remote machine   
   > gets a copy of the metadata from the first machine.   
      
   I repeated the exercise and this time it worked without problem! The old   
   laptop could now see all the backup files on the USB stick, and I was   
   able to restore some selected files and folders from the USB stick to   
   the old laptop's SSD.   
      
   At least with the time saved on trying to solve the issue I was able to   
   upgrade both laptops to LM 22.2.   
      
   --   
   Jeff   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)