Merge PR #27656 into master

* refs/pull/27656/head:
	doc/dev/erasure-coded-pool: update
	doc/rados/operations/erasure-code*: update default ec profile references
	common/options: change default erasure-code-profile to k=2 m=2

Reviewed-by: Neha Ojha <nojha@redhat.com>

doc/dev/erasure-coded-pool.rst

@@ -63,7 +63,7 @@ Set the CRUSH failure domain to osd (instead of host, which is the default)::
      crush-failure-domain=osd
  $ ceph osd erasure-code-profile get myprofile
  k=2
- m=1
+ m=2
  plugin=jerasure
  technique=reed_sol_van
  crush-failure-domain=osd
@@ -72,10 +72,10 @@ Set the CRUSH failure domain to osd (instead of host, which is the default)::
 Control the parameters of the erasure code plugin::
 
  $ ceph osd erasure-code-profile set myprofile \
-     k=3 m=1
+     k=3 m=2
  $ ceph osd erasure-code-profile get myprofile
  k=3
- m=1
+ m=2
  plugin=jerasure
  technique=reed_sol_van
  $ ceph osd pool create ecpool 12 12 erasure \
@@ -87,7 +87,7 @@ Choose an alternate erasure code plugin::
      plugin=example technique=xor
  $ ceph osd erasure-code-profile get myprofile
  k=2
- m=1
+ m=2
  plugin=example
  technique=xor
  $ ceph osd pool create ecpool 12 12 erasure \
@@ -99,7 +99,7 @@ Display the default erasure code profile::
   default
   $ ceph osd erasure-code-profile get default
   k=2
-  m=1
+  m=2
   plugin=jerasure
   technique=reed_sol_van
 
@@ -130,7 +130,7 @@ Set the rule to ssd (instead of default)::
      crush-root=ssd
  $ ceph osd erasure-code-profile get myprofile
  k=2
- m=1
+ m=2
  plugin=jerasure
  technique=reed_sol_van
  crush-root=ssd

doc/rados/operations/erasure-code-lrc.rst

@@ -188,7 +188,7 @@ Erasure code profile examples using low level configuration
 Minimal testing
 ---------------
 
-It is strictly equivalent to using the default erasure code profile. The *DD*
+It is strictly equivalent to using a *K=2* *M=1* erasure code profile. The *DD*
 implies *K=2*, the *c* implies *M=1* and the *jerasure* plugin is used
 by default.::
 

doc/rados/operations/erasure-code.rst

@@ -28,14 +28,14 @@ requires at least three hosts::
 Erasure code profiles
 ---------------------
 
-The default erasure code profile sustains the loss of a single OSD. It
-is equivalent to a replicated pool of size two but requires 1.5TB
-instead of 2TB to store 1TB of data. The default profile can be
+The default erasure code profile sustains the loss of a two OSDs. It
+is equivalent to a replicated pool of size three but requires 2TB
+instead of 3TB to store 1TB of data. The default profile can be
 displayed with::
 
     $ ceph osd erasure-code-profile get default
     k=2
-    m=1
+    m=2
     plugin=jerasure
     crush-failure-domain=host
     technique=reed_sol_van

qa/standalone/mon/osd-erasure-code-profile.sh

@@ -132,7 +132,7 @@ function TEST_set_idempotent() {
     # ceph osd erasure-code-profile set: verify that it is idempotent,
     # as if it was using the same code path.
     #
-    ceph osd erasure-code-profile set default k=2 m=1 2>&1 || return 1
+    ceph osd erasure-code-profile set default k=2 m=2 2>&1 || return 1
     local profile
     #
     # Because plugin=jerasure is the default, it uses a slightly

src/common/options.cc

@@ -2430,7 +2430,7 @@ std::vector<Option> get_global_options() {
     .add_service("mon"),
 
     Option("osd_pool_default_erasure_code_profile", Option::TYPE_STR, Option::LEVEL_ADVANCED)
-    .set_default("plugin=jerasure technique=reed_sol_van k=2 m=1")
+    .set_default("plugin=jerasure technique=reed_sol_van k=2 m=2")
     .set_flag(Option::FLAG_RUNTIME)
     .set_description("default erasure code profile for new erasure-coded pools")
     .add_service("mon"),