[Box Backup] BoxBackup Server Side Management Specs (Draft0.01)

[Ben Summers]

On 23 Sep 2004, at 06:51, Garry Glendown wrote:

> richard_eigenmann wrote:
>> If we implemented such a kind of "backup recognition" algorythm this 
>> could
>> speed up backups of remote laptops as perhaps the documents the 
>> laptop user
>> has been working on have already been backed up from users back at 
>> the base.
>> I imagine this sort of feature could save somewhere between 0.5 and 5 
>> GB per
>> workstation that is doing a full backup. This could be significant to 
>> the
>> scalability of the boxbackup.
>> Of course this sort of thing probably would lead to massive 
>> redevelopment of
>> code and should only be undertaken if there is a very strong demand. 
>> I for
>> one don't need it.
>
> Your suggestion might have been derived from what some companies 
> already sell as backup solutions ... e.g., InterXion, a large hoster, 
> is selling exactly this feature set ... they say they have all mayor 
> Windows version and many M$ apps "on file" and if the version found on 
> the client machine matches the one on file, it is only stored as 
> reference ... they even do this for other files, dynamically extending 
> this to everything stored on their server ... IIRC, they still store 3 
> copies of each file even with matches ...
>
> Setting up such a feature will probably require a database of MD5 (or 
> similar) checksums, filesize plus possibly file names (to reduce 
> search time, at the cost of maybe not recognizing a match, but at the 
> gain of reducing theoretical overlaps in MD5 checksum) ... probably 
> want to define a minimum file size below which you wouldn't want to do 
> all the searching/md5'ing due to little gain by matches ... plus if a 
> file is used as a reference, the server must maintain it as long as 
> there are at least 1 references to it ... if it is changed or deleted 
> on the server it originated at, the old version must be kept intact 
> for the other backups ... some work, but doable ...

I'll add it to my list of features for the future.

>
> But then, at the moment a nice frontend for M$-users might be of a 
> slightly higher importance ...

Yes, there does seem to be a lot of demand for a Win32 version!

Ben