Update architecture.rst:Calculating PG IDs

To Calculate PG ID, if I didn't get it wrong, CRUSH calculates the hash modulo 
the number of PGs instead of OSDs, according to osd/osd_types.cc:963 
ceph_stable_mod(pg.ps(), pg_num, pg_num_mask).

Signed-off-by: Kai Zhang <zakir.exe@gmail.com>
Improvements to radosgw docs
- Correct a typo (`rados-admin`) in admin docs
- Reorder sections in config so "above example" is in expected position
doc: Fix cache tier docs

The instructions for 'osd tier add' were plain
wrong, claiming that the cache mode could
be passed as a third argument.

Signed-off-by: John Spray <john.spray@inktank.com>
Merge pull request #1877 from ceph/wip-tier-doc

doc: Fix cache tier docs

Reviewed-by: Loic Dachary <loic@dachary.org>
mailmap: Florent Flament affiliation

and name normalization

Reviewed-by: Florent Flament <florent.flament@cloudwatt.com>
Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Kevin Dalley affiliation

Reviewed-by: Kevin Dalley <kevin@kelphead.org>
Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Daniel J. Hofmann affiliation

Reviewed-by: Daniel J. Hofmann <daniel@trvx.org>
Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Stephen F Taylor affiliation

Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Stefan Eilemann affiliation

Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Michael Riederer affiliation

and name normalization

Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Walter Huf affiliation

Reviewed-by: Walter J. Huf <hufman@gmail.com>
Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Stuart Longland affiliation

Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Ilya Dryomov name normalization

Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Shawn Edwards affiliation

Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Christian Theune affiliation

Reviewed-by: Christian Theune <ct@gocept.com>
Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Chris Glass affiliation

Reviewed-by: Chris Glass <tribaal@gmail.com>
Signed-off-by: Loic Dachary <loic@dachary.org>
mailmap: Aristoteles Neto affiliation

and name normalization

Reviewed-by: Aristoteles Neto <aristoteles.neto@webdrive.co.nz>
Signed-off-by: Loic Dachary <loic@dachary.org>
Merge pull request #1853 from dachary/wip-mailmap

mailmap updates

each commit has been submitted to the author for review
intial take on ceph-brag-client and tox. Python 2.7 passes

Signed-off-by: Alfredo Deza <alfredo@deza.pe>
add backport of collections.Counter for python2.6

Using Raymond Hettinger's MIT backport

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>