From: nospam@needed.invalid   
      
   On Sun, 11/16/2025 6:13 PM, Felix wrote:   
   > Jeff Layman wrote:   
   >> On 16/11/2025 00:23, Felix wrote:   
   >>>   
   >>> I have all my personal files in folders in the Home directory in the LM   
   >>> folders ie. Documents, Pictures, etc., and also in folders I've created.   
   >>> I want to backup everything in the Home Directory, and I've started   
   >>> using DejaDup. I have configured it to use an internal drive I use for   
   >>> Timeshift Snapshots, but auto backups fail. I get a message 'access   
   >>> denied', so I have to do manual backups. Could this be because the   
   >>> Timeshift drive is not mounted? What would be the best solution? Should   
   >>> I use some other program, if so which is the best and does auto backups?   
   >>> I only want to use GUI apps, I don't want to have to use the terminal.   
   >>> Thanks,   
   >>   
   >> You're using an /internal/ drive for a "backup"? Then you haven't got a   
   backup; you've got a copy of your home folder in effectively the same place as   
   the original one.   
   >>   
   >> A backup needs to be elsewhere, *safely* separate from the original. If   
   your computer gets stolen or a lightening strike gets through to it, you'll   
   lose your data. If you want a real backup, you'll need external storage,   
   whether to a device you plug    
   in, or storage elsewhere such as an attached network or The Cloud. And it's   
   preferable to use three separate storage devices for at least a    
   randfather-father-son backup. I've been using Déjà Dup for many years to   
   backup to three separate USB sticks,    
   and store them away from the laptop. I don't think that it's possible to   
   automate to three separate devices using Déjà Dup, even if it was possible   
   to permanently connect them to the computer.   
   >   
   > makes sense. I will do backups to a USB drive.   
      
   Storage devices have reliability characteristics.   
      
   In some cases, they're hard to predict.   
      
   With my Samsung SSDs, you never see any signs of "bit rot"   
   and declining transfer bandwidth.   
      
   with one of my Lexar NS100 256GB drives, the transfer rate became   
   awfully slow after only three months sitting on the shelf. It seems   
   that the drive firmware has to "rewrite" or "refresh" automation   
   to fix the TLC bit rot. If I left that long enough, I'm convinced   
   that (super-cheap) drive would report some data loss, with enough time.   
   Samsung also had an incident, where they did not like how the flash   
   was behaving, and they offered a new firmware for the product   
   with a "refresh" solution of some sort.   
      
   Hard drives are a little better in that department, as magnetic   
   storage doesn't behave nearly as badly as TLC flash does. I feel confident,   
   when I pick up a 20 year old HDD, that any archival material on it   
   remains undisturbed.   
      
   You can get drive enclosures and put a HDD inside and connect via USB,   
   if you want. Which may be preferable to some of the brands of USB   
   flash based sticks. I have two broken Lexar brand drives on my desk.   
   One only accepted around seven "dd" transfers of ISO files before   
   croaking.   
      
   SLC flash is very good about "prompt" failures. You don't see bit rot   
   in three months with that. It still has the overall ten year retention,   
   just to establish an expectation of storage behavior. They don't make   
   SSDs out of SLC any more. It has a wear life of 100,000 cycles. TLC and   
   QLC are rated 3,000 cycles, and TLC with write amplification is around   
   600 cycles. If you have a modern 1TB SSD, you can do a total   
   of 600 TB of writes to it.   
      
   It all depends on how important the backup materials are, and   
   how long the backups have to last, as to what makes a "good"   
   external storage solution. Some computers have an ESATA connector   
   on the back, but my computer shop has no ESATA cables for it. That's   
   another way to connect a backup device.   
      
      Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)