[tahoe-dev] tahoe backup re-uploads old files

Marco Tedaldi marco.tedaldi at gmail.com
Thu Mar 1 05:51:17 UTC 2012


On 01.03.2012 00:59, Brian Warner wrote:
> On 2/24/12 11:48 AM, Marco Tedaldi wrote:
> 
>>> To my surprise it skipped some old pictures (which I consider normal)
>>> but started uploading one of the old pictures I had for sure not
>>> touched in the mean time.
> 
> It depends upon the timing involved, but "tahoe backup" will check up on
> unchanged files that haven't been checked in a while. If the file was
> last uploaded or checked within a month, it will assume that the shares
> are still ok (so 0% chance of doing a filecheck). Starting at one month
> old, the probability of doing a filecheck grows, until it reaches 100%
> at two months (i.e. if the file hasn't been checked for over two months,
> it will *always* do a filecheck). If the filecheck reports any problems,
> the file is re-uploaded.
> 
Ok... this seems to make sense. Mi initial upload took longer than a
month... the second run was finished withing 3 days. So now the next run
is on the way...

> The idea was to smoothly check up on files that aren't "fresh", to
> detect servers going away or other surprises (like switching grids
> altogether). So my guess is that you started the backup more than a
> month ago, now tahoe is starting to check up on those files, and either
> some servers have gone away or are temporarily offline, so it decides it
> needs to re-upload the files.
> 
Hm... but this would not explain, why it seen 0 shares already present.
Or could this happen, because I've changed some settings (shares,
happy..) in the meantime?

> Does that seem to match what you're observing?
> 
at least part of it is explained. Thanx a load!

but wouldn't tahoe deep-check do this as well?

>> (oh yeah, i've deleted some random parts of the URI... if you need the
>> whole uri, I can give it out by PM. It's not that these images are big
>> secrets)...
> 
> Incidentally, if you want to safely mangle a CHK filecap like:
> 
>> 'URI:CHK:gxtbrbfds5x63jbcnu4jaq:qzqfninxxp37itz46omv77jk7z65tj5q3rij4aa:5:11:47963680'
> 
> then the important thing to hide is the third field ("gxtbrb.."). That's
> the part that contains the decryption key. The rest is
> publically-visible integrity-checking data and share-counts/filesizes.
> 
Oh, thanx. good to know for the future....


best regards

Marco



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