[GTALUG] Backups for files

o1bigtenor o1bigtenor at gmail.com
Thu Nov 5 13:46:05 UTC 2015


On Thu, Nov 5, 2015 at 10:47 AM, D. Hugh Redelmeier <hugh at mimosa.com> wrote:
> | From: o1bigtenor <o1bigtenor at gmail.com>
>
> | Looking at backing up a little less than 300 GB of files. Want to do
> | one copy to 25 GB Bluray discs.
>
> I think about this but don't act on it.

I'm thinking that this is quite true of most of us!!!
>
> I don't know the perfect solution.  I've had ALL kinds of media go bad
> or unreadable due to loss of technology.
>
> The best bet (and I don't do this) is to have multiple copies on
> multiple media.  Actively backed up (i.e. in a rolling repeated
> process, onto new media as they becomes available).  Physically
> separated (so one fire, flood, or war doesn't take it out).
>
> All media age in some ways, not all known ahead of time.
>
> I've had CD's physically destroyed by plasticizer from the window on
> the paper sleeve they were stored in.  It took a number of years.
> Threats can come from out of left field.
>
> The lifetime of media seem to have a LIFO nature.  Newer stuff is
> often more delicate (and made obsolete sooner).
>
> - stone tablets came first and outlast most of their successors
>
> ...
You forgot papyrus reed stuff

then came parchment
>
> - paper from before ~1850 last a long long time
>
> - later paper (from wood pulp) last a long time (but less than older paper).
>   I have books that I bought new that are deteriorating from the acid
>   in the paper.
>
> - punch cards and paper tape seem to last indefinitely (I have modest amounts)
>   and I can read them by hand.  I think I could build my own reader if
>   I felt the urge.
>
> - 9-track tapes (I have some backups on them) aren't useful any
>   longer because the drives are expensive and rare.  Probably the
>   recordings have decayed but I have no way of finding out.
>
> - 8", 5.25", 3.25" floppies are starting to fall off the edge.
>
> - LASER disks and magneto-optical disks appear to be gone.
>
> - MFM and RLL disks are no longer supported.
>
> - SCSI and (p)ATA disks are all but gone.
>
> But maybe your information will be unimportant before any of this
> kicks in.
>
> There are DVD's that claim to have very long lifetimes.  They might be
> worth a shot. <https://en.wikipedia.org/wiki/M-DISC>
>
> Blu-rays seem to have little takeup for data.  I don't even know if
> Linux has software to master them.  I would avoid them.  (I bought a
> Blu-ray burner but have never used it for Blu-rays.  It can also burn
> M-Discs but I haven't used that feature yet.)

Have on and am using it but it takes about an hour to burn about 24 GB
which makes it a slow process when you have say a TB of data!
>
> USB flash-memory sticks are very convenient.  I have no confidence
> that their lifetime will be long and reliable.  Anyone know?
>
> For our most important records we still keep paper.

The easiest to destroy, change and do - - - hmmmmmm so much for
the paperless office that was promised way back in the 80s!

Dee


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