I think we have a winning idea here. Thanks.

Josh Welker

-----Original Message-----
From: Code for Libraries [mailto:[log in to unmask]] On Behalf Of Randy Fischer
Sent: Friday, January 11, 2013 3:46 PM
To: [log in to unmask]
Subject: Re: [CODE4LIB] Digital collection backups

On Fri, Jan 11, 2013 at 2:45 PM, Joshua Welker <[log in to unmask]> wrote:

> Reading the Glacier FAQ on Amazon's site, it looks like they provide 
> an archive inventory (updated daily) that can be downloaded as JSON. I 
> read some users saying that this inventory includes checksum data. So 
> hopefully it will just be a matter of comparing the local checksum to 
> the Glacier checksum, and that would be easy enough to script.

One could also occasionally spin up local EC2 instances to do the checksums in the same data center, and ship just that metadata down - you would not
incur any bulk transfer costs in that case (if memory serves).   DAITSS
uses both md5 and sha1 checksums in combination, other preservation systems might require similar.

-Randy Fischer