On Thu, 10 Nov 2016, Erik Soderquist wrote:
Date: Thu, 10 Nov 2016 17:16:53 -0500
From: Erik Soderquist <eriksoderqu...@gmail.com>
To: cygwin@cygwin.com
Subject: Re: Complaining after fair notice of dropping XP support. Was: Not
very nice at all.
Greetings, Erik,
On Thu, Nov 10, 2016 at 2:19 PM, Peter A. Castro wrote:
And for those who think keeping a private mirror is trivial, let me give you
some stats. A full snapshot of Cygwin, 32-bit + 64-bit (+noarch) + source
packages (Current and Previous) is about 137Gb. Don't believe me? Your
setup.ini has a size (and a hash) for every package. Add them up yourself.
Now consider that I have about 4000 snapshots (and counting!) of Cygwin.
Oh! Quick quiz:
What's 137Gb * 4000?
Answer: 535Tb.
Now, do you really think I have that amount of storage? Of course not. The
Time Machine isn't organized like that (don't be silly). It's currently
about 500Gb (which is quite a savings, if you think about it :-)
I would dearly love to know more about how you did this specific piece...
A good magician never reveals how the trick works. 8^)
Sadly I'm not a good magician.
It's not all that complicated, if you think about it. Each time a new
setup.ini is generated only a hand full of packages was actually updated,
so really, day-to-day, there's not all that much change.
I keep a delta database and each time I grab a new setup.ini I compare all
of the packages listed to my existing database. Anything new, I pull down
and add to the archive. Anything already present I don't re-pull. Think
of it as de-duplication on a package level (though I do this for more
than just setup.ini, but that's a separate trick).
It's only if you decide you want a complete copy of all packages for any
given circa that the amount of data instantiating is alot.
Then, from the setup.ini, I create a new circa directory and, really, the
smoke-and-mirrors of the trick is that it's all symlinks to the real
package storage, of which I have exactly one copy. Hence, 500Gb
instead of 535Tb.
So, um, "Ta-da"! :-)
Oh, this is all automated, btw. I hardly touch it except to clean out
old logs and do backups from time to time.
Sorry, it wasn't all that good a trick, was it.
-- Erik
--
--=> Peter A. Castro
Email: doctor at fruitbat dot org / Peter dot Castro at oracle dot com
"Cats are just autistic Dogs" -- Dr. Tony Attwood
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