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authorGuillaume Abrioux <gabrioux@redhat.com>2020-03-04 00:00:41 +0100
committerGuillaume Abrioux <gabrioux@redhat.com>2020-03-05 00:13:50 +0100
commit25b66674597683494592f6555975abc308d9bb86 (patch)
treee9ef712bcecd02724ae79c545210c3f5f4abec97 /doc/rados
parentMerge PR #33663 into master (diff)
downloadceph-25b66674597683494592f6555975abc308d9bb86.tar.xz
ceph-25b66674597683494592f6555975abc308d9bb86.zip
doc: update erasure-code-profile.rst
Update this part of the documentation to reflect the change made by 3e86be7d50d485dbcce50d99d2f52891ca7bd399 Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
Diffstat (limited to 'doc/rados')
-rw-r--r--doc/rados/operations/erasure-code-profile.rst10
1 files changed, 6 insertions, 4 deletions
diff --git a/doc/rados/operations/erasure-code-profile.rst b/doc/rados/operations/erasure-code-profile.rst
index 3a73eb344ed..45b071f8ad7 100644
--- a/doc/rados/operations/erasure-code-profile.rst
+++ b/doc/rados/operations/erasure-code-profile.rst
@@ -8,10 +8,12 @@ Erasure code is defined by a **profile** and is used when creating an
erasure coded pool and the associated CRUSH rule.
The **default** erasure code profile (which is created when the Ceph
-cluster is initialized) provides the same level of redundancy as two
-copies but requires 25% less disk space. It is described as a profile
-with **k=2** and **m=1**, meaning the information is spread over three
-OSD (k+m == 3) and one of them can be lost.
+cluster is initialized) will split the data into 2 equal-sized chunks,
+and have 2 parity chunks of the same size. It will take as much space
+in the cluster as a 2-replica pool but can sustain the data loss of 2
+chunks out of 4. It is described as a profile with **k=2** and **m=2**,
+meaning the information is spread over four OSD (k+m == 4) and two of
+them can be lost.
To improve redundancy without increasing raw storage requirements, a
new profile can be created. For instance, a profile with **k=10** and