Since kraken, Ceph enforces a 1:1 correspondence between CRUSH ruleset and
CRUSH rule, so effectively ruleset and rule are the same thing, although
the term "ruleset" still survives - notably in the CRUSH rule itself, where it
effectively denotes the number of the rule.
This commit updates the documentation to more faithfully reflect the current
state of the code.
Fixes: http://tracker.ceph.com/issues/20559
Signed-off-by: Nathan Cutler <ncutler@suse.com>
1) ruleset is an obsolete term, and
2) crush-{rule,failure-domain,...} is more descriptive.
Note that we are changing the names of the erasure code profile keys
from ruleset-* to crush-*. We will update this on upgrade when the
luminous flag is set, but that means that during mon upgrade you cannot
create EC pools that use these fields.
When the upgrade completes (users sets require_osd_release = luminous)
existing ec profiles are updated automatically.
Signed-off-by: Sage Weil <sage@redhat.com>
A short introduction to the first time user of an erasure coded pool.
It includes a reminder of how it relates to cache tiering and links to
define new profiles with an example.
There was examples in the developer documentation but the operator
expects to find such a guide in the rados operations chapter.
http://tracker.ceph.com/issues/9970Fixes: #9970
Signed-off-by: Loic Dachary <ldachary@redhat.com>