Server Migration documentation rsync update

Clemens Koller clemens.koller at
Tue Sep 5 14:07:53 UTC 2006

Hi, Johannes!

Johannes Winkelmann wrote:
> Hi,
> On Tue, Sep 05, 2006 at 11:07:11 +0200, Clemens Koller wrote:
>>Hi, Johannes!
> [...]
>>>Rest assured that if we had a way to calculate the estimated traffic, we
>>>would have told you in the very first mail covering this subject.
>>I don't expect that you tell me the estimated traffic. It would
>>be sufficient to know the current traffic or port download frequency
>>of the port downloads. (rsync, httpup, cvsup)
> Could you maybe just quickly elaborate of the relation between the
> traffic of the ports tree and the size of the distfiles, or is this
> number just of general interest to you?

It's not about guessing some formula without knowing what data is
available, but here you are:

The exact bw of such a distfile mirror is computed as:

average port updates = bw of the ports tree traffic / average port size

Given: ports -u is followed by a prt-get sysup
Given: all packages of a port are used / updated
(worst case after a fresh install)
Given: i.e. 1% of the distfile sources fail

average distfile backuprequests = 0.01 * average port updates
average distfile mirror bandwith = average distfile backuprequests * average distfile size.

q.e.d. ;-)

Best greets,

Clemens Koller
R&D Imaging Devices
Anagramm GmbH
Rupert-Mayer-Str. 45/1
81379 Muenchen
Phone: +49-89-741518-50
Fax: +49-89-741518-19

More information about the CRUX mailing list