[Box Backup] Box Backup 0.11rc on OS X 10.5

[Chris Wilson]

Hi Achim,

On Mon, 16 Mar 2009, Achim J. Latz wrote:

> I learned about Box Backup through a very interesting Usenix paper [0] 
> that mainly talks about another remote backup system called Cumulus.

Thanks, I had never heard of Cumulus but it's interesting reading. They 
have implemented two features that I've wanted to implement in Box for a 
while, but haven't had time: snapshots and S3 support. Their evaluation is 
also very interesting. I think I might give it a try.

> 1/ I have read in a couple of comments that the OSX client works great, 
> but that the server is not usable. Is there some more information
> about what is failing? The build tests fail with "backupstore: FAILED: 5
> tests failed (first at testbackupstore.cpp:1201)"

I think this is it. There appears to be some caching or weird behaviour 
where a created file doesn't immediately appear and a deleted file doesn't 
immediately disappear under Darwin. This causes some tests to fail and 
makes me not trust it as Box Backup wasn't designed to work under those 
assumptions. A copy of the test log might help me to be more specific. It 
was about three years ago that I last tested Box server on Darwin. I did 
get all tests passing on MacOS X more recently, which makes me think that 
the problem might have been fixed.

> As you can see, the only critial failure is the preservation of 
> timestamps. More specifically, this test consists of files and folders 
> with future timestamps. The files are correctly restored by Box Backup, 
> but the folder is always created with today's date. Given that the 
> folders in the backup storage are always stored with a 1970's date, I 
> was wondering if this could be fixed so that folders also retain their 
> creation date, just like files do already? This would be a fantastic 
> addition to Box Backup's capabilities.

Why? What's so important about folder timestamps anyway? Box Backup is 
deliberately designed not to preserve them.

> 3/ In addition to 2/, it appears that rsync with certain patches is able 
> to pass all Backup Bouncer tests [3]. Would it be possible to lift other 
> capabilities such as hard-links and ACLs from rsync and implement them 
> in Box Backup?

Unfortunately not. Box Backup is not rsync or rsync+encryption. It's an 
encrypted filesystem with some backup features and the ability to do 
*rsync-like* delta uploads of encrypted files.

Cheers, Chris.
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