Gentoo Archives: gentoo-dev

From: Ricardo Correia <gentoo-dev@××××.org>
To: gentoo-dev@××××××××××××.org
Subject: Re: [gentoo-dev] Proposal for an alternative portage tree sync method
Date: Tue, 22 Mar 2005 23:58:57
In Reply to: Re: [gentoo-dev] Proposal for an alternative portage tree sync method by Daniel Drake
1 On Tuesday 22 March 2005 12:45, Daniel Drake wrote:
2 > So on every sync, you have to download the entire 260mb ISO file?
3 >
4 > I don't think our mirrors would be very happy about that.
5 >
6 > Daniel
7 > --
8 > gentoo-dev@g.o mailing list
10 You don't seem to have understanded how zsync works.
12 Suppose that I, as a user, already have yesterday's portage ISO file.
13 And suppose that today, there's about 30 new or updated ebuilds.
14 Also suppose that those ebuilds amount to something like 500 KB.
16 In those conditions, if I update my ISO file today using zsync, I would only
17 have to download the zsync file (which would be about 700 KB) and the
18 necessary *compressed* ranges of the (compressed) ISO file available on the
19 mirror. This would be *less* than 500 KB, because of the compression.
21 This works because the .zsync file contains a mapping of the uncompressed data
22 to the compressed data.
24 Notice that even if the user doesn't have the ISO file yet, he would only have
25 to download about 27 MB.
27 Personally, I estimate that updates could be faster than a rsync, if not only
28 because of the whole disk thrashing. But only through experimentation we
29 would be able to measure the difference.
31 Also notice that zsync still has lots of room for improvements, so I wouldn't
32 be surprised to see it beat rsync in terms of time of an update.
34 I think it's worthwhile to setup an experimental mirror, it sure seems much
35 better than doing emerge-webrsync..
36 --
37 gentoo-dev@g.o mailing list


Subject Author
Re: [gentoo-dev] Proposal for an alternative portage tree sync method Fabian Zeindl <fabian.zeindl@×××.at>