Re: Apt and rsync... I know...
Florian Weimer <fw@deneb.enyo.de> writes:
> Florian Weimer wrote:
>
> > I'm not sure if rsync is the right format for that. VCDIFF (RFC 3284)
> > should result in smaller deltas and less CPU overhead. However, I don't
> > know of any free implementation (Subversion has code that does something
> > very similar, though). The format itself is not encumbered by patents,
> > AFAIK.
>
> Just for reference, here are a few numbers. I compared the data.tar
> part of libc6_2.3.2.ds1-10 and libc6_2.3.2.ds1-11 (i386 architecture).
>
> Delta sizes are:
>
> rdiff 7302952
> rdiff (gzip -9) 2423336
> svndelta 1793107
> svndelta (gzip -9) 1539271
> xdelta (-0) 1751110
> xdelta (-9) 935281
>
> svndelta is quite CPU-intensive, compared to the others. (I'm not sure
> if it's because of the base64 encoding, which isn't included in the
> numbers above.) xdelta and rdiff use comparable amounts of CPU time
> (with and without compression). xdelta seems to need memory proportional
> to the size of the input files, which might be a problem.
And what does rsync say? Ucompressed, gzip -9 and gzip with
--rsyncable please.
MfG
Goswin
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