Jump to content

Backup Size Discrepancy

Recommended Posts

We have just moved to Retrospect 9.0.2 from a previous version. Our first two Backups however have been showing us something strange.


We receive no errors and the checksums read as correct but when we compare the file size in the finder versus what Retrospect displays they are different sizes.


EX: First backup is 437G but retrospect says it backed up 412.7G

Second Backup 470G but Retrospect says it backed up 444.1G


Stranger still, when we pull back an individual file for confirmation it will say it is the wrong size in Retrospect but upon restore it is the same size as the original in the finder.


I will include some screen grabs for clarification. Any Help would be much appreciated. Thanks.




Link to comment
Share on other sites

Thanks for the fast reply!


That's what I was thinking but I'm glad to hear someone confirm it. We are coming from Version 6.1.230 which did use the same "GB" as Finder, so we wanted to double check before clearing some of that material.


Thanks again.

Actually, it's the new Finder that changed in Snow Leopard.

I assume you ran Retrospect 6 on something older than Snow Leopard?





New Math

Lastly — and whether this is a bug or a feature is really a matter of opinion — the new Finder has changed how it calculates kilo, mega and gigabytes. By traditional computer conventions, thousands and millions are not base-10 numbers, but are the nearest power of two. A kilobyte was 1024 bytes, a megabyte was 1,048,576, and a gigabyte was 1,073,741,824.

The new Finder dispenses with old geek habits in favor of powers of ten (which is consistent with the latest terminology standards). A thousand is a thousand, a billion is a billion — not a billion plus 7.4%! As a result, not only will you get some real disk space back by installing Leopard, it will also look like you got even more, because what was 50 GB of free space when calculated using those powers of two in Leopard is now 53.7 GB as calculated using the tens system you learned in Kindergarten, which is what Snow Leopard uses.




Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...