Wordsmith the erasure-code doc a bit

Signed-off-by: Dan Mick <dan.mick@inktank.com>

diff --git a/doc/dev/erasure-coded-pool.rst b/doc/dev/erasure-coded-pool.rst
index 3dbd95698b333ef37d24bfb5708627a7faa41f36..8ae57d4321a576514868aa0c8c700c1466aaa877 100644 (file)
--- a/doc/dev/erasure-coded-pool.rst
+++ b/doc/dev/erasure-coded-pool.rst
@@ -4,10 +4,10 @@ Erasure Coded pool
 Purpose
 -------
 
-Erasure coded pools requires less storage space compared to replicated
-pools. It has higher computation requirements and only supports a
-subset of the operations allowed on an object (no partial write for
-instance).
+Erasure-coded pools require less storage space compared to replicated
+pools.  The erasure-coding support has higher computational requirements and
+only supports a subset of the operations allowed on an object (for instance,
+partial write is not supported).
 
 Use cases
 ---------
@@ -15,7 +15,7 @@ Use cases
 Cold storage
 ~~~~~~~~~~~~
 
-An erasure coded pool is created to store a large number of 1GB
+An erasure-coded pool is created to store a large number of 1GB
 objects (imaging, genomics, etc.) and 10% of them are read per
 month. New objects are added every day and the objects are not
 modified after being written. On average there is one write for 10,000
@@ -23,10 +23,10 @@ reads.
 
 A replicated pool is created and set as a cache tier for the
 replicated pool. An agent demotes objects (i.e. moves them from the
-replicated pool to the erasure coded pool) if they have not been
+replicated pool to the erasure-coded pool) if they have not been
 accessed in a week.
 
-The erasure coded pool crush ruleset targets hardware designed for
+The erasure-coded pool crush ruleset targets hardware designed for
 cold storage with high latency and slow access time. The replicated
 pool crush ruleset targets faster hardware to provide better response
 times.
@@ -35,10 +35,10 @@ Cheap multidatacenter storage
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Ten datacenters are connected with dedicated network links. Each
-datacenters contain the same amount of storage, have no power supply
-backup and no air cooling system.
+datacenter contains the same amount of storage with no power-supply
+backup and no air-cooling system.
 
-An erasure coded pool is created with a crush map ruleset that will
+An erasure-coded pool is created with a crush map ruleset that will
 ensure no data loss if at most three datacenters fail
 simultaneously. The overhead is 50% with erasure code configured to
 split data in six (k=6) and create three coding chunks (m=3). With
@@ -47,17 +47,17 @@ replication the overhead would be 400% (four replicas).
 Interface
 ---------
 
-Set up an erasure coded pool::
+Set up an erasure-coded pool::
 
  $ ceph osd create ecpool 12 12 erasure
 
-Set up an erasure coded pool and the associated crush ruleset::
+Set up an erasure-coded pool and the associated crush ruleset::
 
  $ ceph osd crush rule create-erasure ecruleset
  $ ceph osd pool create ecpool 12 12 erasure \
      default ecruleset
 
-Set the ruleset failure domain to osd instead of the host which is the default::
+Set the ruleset failure domain to osd (instead of the host which is the default)::
 
  $ ceph osd erasure-code-profile set myprofile \
      ruleset-failure-domain=osd