Verify copied files?

Nov 24, 2009 at 7:40 PM

I may be revealing my ignorance here, but is there a way to verify that the file(s) copied to S3 is/are intact? This is a great tool that I want to use to back up my IIS logs (and other things) to S3. Is there any verification built-in to the protocol, or is there a command or technique I can use to ensure that the file on S3 is good before I delete my local copy? Thanks!

Nov 25, 2009 at 1:22 AM


The files are guaranteed to have uploaded, and both ethernet and the IP protocol have checksums to detect errors so you can be pretty confident that they've uploaded without corruption.  However, corruption is still possible and it has happened on S3 (once ever that I know of, due to some very faulty hardware at Amazon).  I will soon add MD5 checking to the application, which is a near-perfect check that no corruption has occurred.  If you're waiting on it please let me know and I'll get it done sooner.  (And if you can blog or otherwise publicise this project I'll get it done even quicker!)




Nov 25, 2009 at 1:33 AM

Thanks Max,

It would be fantastic to get the MD5 checking in sooner than later. I'd feel a whole lot more comfortable with my backup (I guess I'm actually archiving, since I'm deleting after copying) solution then. If I blogged or tweeted, I'd be sure to mention this project, as I think it's a really valuable tool. Since I don't (yet), I'll try to spread the word through Facebook and LinkedIn.

Thanks again,


Nov 25, 2009 at 3:31 PM

OK, this is available now: