[CentOS] Re: Linux backup help
warren at etr-usa.com
Sat Nov 15 01:43:58 UTC 2008
Amos Shapira wrote:
> Assuming I take the approach you suggest and have to restore the cache
> (with the tested versions) after it's lost in a disaster, is there a
> way to do that (short of backing it up)?
I don't see why this is a big deal.
First off, even way out at the end of a RHEL/CentOS release's lifetime,
the full set of patched packages will be just a few gigs of data. (It
almost *has* to be smaller than a single-layer DVD...the patch set can't
practically be bigger than the original OS it's patching.) Today, a
couple of gigs costs nearly nothing to store, and 3 years from now when
the last CentOS 5 patches come out, storage and bandwidth costs will be
1/4 what they are now.
Second, this scheme replicates the cache to multiple machines. Most of
the time, only a single machine will get killed at a time, so you can
get the cache copy from one of its neighbors. If you're worried about a
disaster that can take out a whole building's worth of machines at once,
surely the cost of a few gigs of professional off-site storage isn't out
of the question?
I keep the most precious 4 GB of my home data backed up on Amazon S3.
This costs me about 75 cents a month. The solution I'm proposing would
take maybe half that out at the end of its useful life, and more like
1/10 that today. Total cost over three years is maybe the cost of lunch
for you and a few friends. You'll spend more than that of your
company's time writing the script to pull the data from a public
repository, and on top of that it's a waste of someone else's bandwidth
to treat them as your company's backup system.
> move around entire cache backups across continents.
Continents?? What, now we're worried about protecting against total
continental destruction? Maybe you're thinking you'll need those
backups to help reboot civilization on another continent?
Sheesh, talk about overengineering... I would have thought that sending
backups to another time zone would be more than sufficient.
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