ceph/doc
Loic Dachary 9c825ec2c4 documentation: revise placement group number guide
When a cluster has few OSDs (less than 50) propose a preselection of
values: as long as the number of placement groups is not too small nor
too large, it won't make much of a difference anyway.

Users of small clusters tend to blindly apply the (OSD*100)/(pool size)
formula and worry about chosing a wrong value because they do not
understand the tradeoffs. The preselection will hopefully save them from
this uncertainty.

Add an explanation of how placement groups relate to OSDs, CRUSH and
pools to help understand the tradeoffs. Explain the
tradeoffs (durability, distribution and resource usages) with examples.

Signed-off-by: Loic Dachary <loic-201408@dachary.org>
Reviewed-by: Gerben Meijer <infernix@gmail.com>
Reviewed-by: Laurent Guerby <laurent@guerby.net>
2014-09-23 16:54:50 +02:00
..
_templates doc: fix missing bracket 2014-09-04 13:44:37 -04:00
_themes/ceph doc: alter doc CSS for the removal of Apex Sans 2014-05-28 22:55:01 +00:00
api add calamari to the api/index section 2014-08-14 10:02:25 -04:00
cephfs doc: add notes on using "ceph fs new" 2014-08-18 17:47:31 +01:00
changelog doc/changelog: v0.67.10 notes 2014-08-12 12:36:47 -07:00
dev documentation: tiering typo 2014-09-19 15:05:27 +02:00
images doc: Added source file for graphic. 2014-01-16 16:11:01 -08:00
install doc/install/manual-deployment: move 'done' comment up 2014-08-28 14:34:27 -07:00
man/8 rbd-replay: Add --dump-perf-counters option 2014-09-11 16:48:08 -07:00
mon
rados documentation: revise placement group number guide 2014-09-23 16:54:50 +02:00
radosgw doc: Update logging path to reflect log rotate script default path. 2014-09-05 14:17:47 -07:00
rbd doc: Updated authentication notes. Fixed syntax error. 2014-09-11 10:50:22 -07:00
scripts Update Python hashbang to respect environment 2014-03-11 20:46:53 +11:00
start doc: Added feedback. 2014-09-15 11:10:35 -07:00
.gitignore
architecture.rst doc: Fixed syntax error. 2014-09-11 10:50:42 -07:00
conf.py doc: Common graph used in 2 quick start files 2014-05-07 18:01:52 -07:00
favicon.ico
glossary.rst doc: Define RADOS in glossary 2014-05-29 14:03:30 -07:00
index.rst doc: Removed quick guide and wireshark from top-level IA. 2014-08-18 14:29:09 -07:00
logo.png
PendingReleaseNotes
release-notes.rst doc/release-notes: v0.85 2014-09-08 12:19:34 -07:00