noted that the official mirrors are supposed to be good; explicated a couple of sentences; explained exactly what the US mirror admins should do (their situation is special)

CVS version numbers

english/mirror/ftpmirror.wml: 1.52 -> 1.53

1 files changed, 22 insertions, 5 deletions

diff --git a/english/mirror/ftpmirror.wml b/english/mirror/ftpmirror.wml
index 0e4586f9e20..7eaa9cc38e7 100644
--- a/english/mirror/ftpmirror.wml
+++ b/english/mirror/ftpmirror.wml
@@ -49,19 +49,36 @@ security.debian.org instead.</p>
 <p>Many people seem to think that <code>ftp.debian.org</code> is the
 canonical location of Debian packages and that it will be best for them
 to mirror from that site. This is <strong>not true</strong>.
-<code>ftp.debian.org</code> is merely one of several servers that get
-updated from an internal Debian server.</p>
 
-<p>Any of the servers in the <a href="list-full">full list of mirrors</a>
-that have the tags '<kbd>Type: Push-Primary</kbd>' or
+<p><code>ftp.debian.org</code> is merely one of several servers that get
+updated from an internal Debian server. That address is presently located
+on a single server in the United States, and it still exists mainly for
+backwards compatibility.</p>
+
+<p>The <a href="official">official mirrors</a> are meant to be a good place
+to mirror from. Any of the servers in the <a href="list-full">full list of
+mirrors</a> that have the tags '<kbd>Type: Push-Primary</kbd>' or
 '<kbd>Type: Push-Secondary</kbd>' should be good to mirror from.
-Please use one that is network-geographically close to you.</p>
+Please use one that is close to you both network-wise and geographically.</p>
 
 <p>There is no real difference between different <em>Push-Primary</em>
 mirror servers as far as mirroring is concerned. On the other
 hand, if many people use ftp.debian.org (and unfortunately, they do), this
 needlessly wastes the donated bandwidth.</p>
 
+<p>Mirror administrators in the United States should mirror from
+ftp.us.debian.org (the official mirror address from the US, which is a
+Push-Primary mirror). But, since that address is also a round-robin alias
+for several machines, it usually makes sense to determine which of the
+components is the best and then mirror from that particular one.
+<br>
+<small>The upside of doing that is that it avoids the risk of failures
+when performing a two-stage rsync (different stages might end up on
+different machines during time windows where they have different data,
+causing a race condition). The downside is that it concentrates on
+a single site the performance of which may vary, but that is currently
+inherent to our mirror network in general.</small></p>
+
 <toc-add-entry name="how">How to mirror</toc-add-entry>
 
 <p>The recommended method of mirroring is with