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Re: Guide(s?) to backup philosophies

On Mon, Mar 13, 2017 at 12:38 PM, Dan Purgert <dan@xxxxxxxx> wrote:
> David Christensen wrote:
>> On 03/11/2017 07:10 AM, Richard Owlett wrote:
>>> I've vague ideas of what backup pattern(s) I might follow.
>>> I'm looking for reading materials that might trigger "I hadn't thought
>>> of that" moments.
>>> Suggestions?

I didn't see anybody talk about incremental backup (the backup
consists of current versions as well as earlier ones -- often earlier
work can replace erroneous or lost current work. Or work you don't
notice is gone for a few days.). There are 2 I know of, and one (and
probably many more) that may do that:

Apple's TimeMachine

TM backs up forever -- you can recover (many) things from the day it started.
It backs up every few minutes without being told to.
It's smart about keeping recent files and tossing pretty old ones.
It's trivial to get going.

It backs up to a single disk.
It's GUI is kind of cutesy and a bit hard to use.
It's Mac only.
Macs change every few minutes. But I've been using it since it came
out (one of the Leopards), and it's not changed, AFAIK.


It backs up using tar files so it's possible (but significant trouble)
to recover data when the Amanda server fails.
It can be configured to use many different pieces of medium.
It writes to tape or disk. I don't know if it does cloud.
It backs up an entire network.
It checks its output, if asked, after backup.
Cron can run it at 3:00 in the morning.

Configuration is pretty complex and time consuming.
There has to be an Amanda client on every host it's to back up.
There has to be an 'Amanda buffer disk' (from the tape days).
It's old -- no GUI. But it's solid as a rock.
Since there's no GUI, it takes a little thought and an instruction
book/man page to recover (it does me, anyway).
When a file has changed, it writes the entire file, not just the
changes (could be considered a pro).


I really don't know much about this one except that it writes using a
proprietary system. Or it did last time I looked (and rejected it for
that reason).

I've been using Amanda with tape for over a decade. No probs. Backing
up and recovering. I've never had to do a bare metal restore, though.
Nor have I ever tried to recover from one of its tarballs.

It's written in C, and beware, I've seen at least one goto in the
source (I've seen the source because it's Debian free -- I think
Backula is too).

I've been on Amanda and tape from the beginning, back in the dark
ages, but I suspect it'd be happy to write to a handful of large(ish)
thumb drives. Another way of getting an incremental backup is to
mirror an entire system every day to a different device from a
collection of removable media (like thumb drives). That'd be a problem
for the likes of Google or Amazon, but might work well for a small

Glenn English