From: rich@example.invalid   
      
   bad sector  wrote:   
   > On 5/28/25 8:01 AM, Rich wrote:   
   >> bad sector  wrote:   
   >>> I hadn't used any blu-ray since the early 'failures' epoch and was   
   >>> surprised to see 'archival' quality printed on a small stack that I just   
   >>> bought. Don't really know what the 'archival' difference is but there   
   >>> seems to me a strong market for the 25gb frisbies.   
   >>   
   >> Assuming "archival" is not simply a word inserted by the marketing   
   >> department without any backing, "archival" for optical media usually   
   >> refered to the use of dyes that were supposedly stable over a longer   
   >> term time range.  With the intent being that the dyes are not supposed   
   >> to fade over just a few short years of storage.   
   >   
   > It's from Verbatim, not a fly-by-night outfit but I havent' found any   
   > 'details' as to exactly what makes them archival.   
      
   The details, if they even exist, won't likely appear on any of the   
   marketing material.  You'd have to go find the equivalent of an   
   electronic chip "data sheet" for the disks to likely find any details   
   of "what makes them archival".   
      
   > "Stored data is engraved on a patented inorganic write layer – it   
   > will not fade or deteriorate.  Engraving process renders these   
   > archival grade discs practically impervious to environmental   
   > exposure, including light, temperature and humidity"   
      
   If that's in the marketing material, then that's as close to "what   
   makes them archival" as you'll likely find there.  And that is a longer   
   worded version of "use of dyes that were supposedly stable over a   
   longer term time range".   
      
   > Fot the price you can buy a cheap 1tb ssd and make it host 40 backups of   
   > your 25gb data, but what happens to things magnetic or electic during a   
   > pole flip?   
      
   True, but what happens to your 40 backups when the SSD drive decides to   
   give up the ghost.  This is why real 'backups' require some form of   
   redundancy, whether multiple SSDs so one failing does not erase   
   everything, or plural copies on 'archival' bluray disks so one disk   
   failing does not take out "the only copy of X".   
      
   > What makes them good backups is that you cannot accidentally   
   > delete an entire folder (got the T-shirts) ...they're not even in the   
   > computer once done.   
      
   If your only copy of data X is only on a single disk, it is no more a   
   "good backup" than if your only copy of X were on a single SSD or a   
   single mechanical drive.   
      
   The read only aspect makes them impervious to accidental overwrite.   
   That has advantages, but does not make them "a good backup" alone.   
      
   Removability makes for easier expansion to a larger number of disks.   
      
   But neither rises to the level of "makes a good backup" without also   
   including redundant copies.   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)