From e9d331c5d87a97a4220e3c702339fb0bde11e93e Mon Sep 17 00:00:00 2001 From: Thomas Lamprecht Date: Wed, 4 May 2022 07:32:57 +0200 Subject: [PATCH] ceph: ec: fix quoting of params and special values Signed-off-by: Thomas Lamprecht --- pveceph.adoc | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/pveceph.adoc b/pveceph.adoc index abc749b..870ca6c 100644 --- a/pveceph.adoc +++ b/pveceph.adoc @@ -553,27 +553,27 @@ Erasure Coded (EC) Pools Erasure coded (EC) pools can offer more usable space for the price of performance. In replicated pools, multiple replicas of the data are stored -('size'). In erasure coded pool, data is split into 'k' data chunks with -additional 'm' coding chunks. The coding chunks can be used to recreate data -should data chunks be missing. The number of coding chunks, 'm', defines how +(`size`). In erasure coded pool, data is split into `k` data chunks with +additional `m` coding chunks. The coding chunks can be used to recreate data +should data chunks be missing. The number of coding chunks, `m`, defines how many OSDs can be lost without losing any data. The total amount of objects -stored is 'k + m'. +stored is `k + m`. -The default 'min_size' of an EC pool depends on the 'm' parameter. If 'm = 1', -the 'min_size' of the EC pool will be 'k'. The 'min_size' will be 'k + 1' if -'m > 1'. The Ceph documentation recommends a conservative 'min_size' of 'k + 2' +The default `min_size` of an EC pool depends on the `m` parameter. If `m = 1`, +the `min_size` of the EC pool will be `k`. The `min_size` will be `k + 1` if +`m > 1`. The Ceph documentation recommends a conservative `min_size` of `k + 2` footnote:[Ceph Erasure Coded Pool Recovery {cephdocs-url}/rados/operations/erasure-code/#erasure-coded-pool-recovery]. -If there are less than 'min_size' OSDs available, any IO to the pool will be +If there are less than `min_size` OSDs available, any IO to the pool will be blocked until there are enough OSDs available again. -NOTE: When planning an erasure coded pool, keep an eye on the 'min_size' as it +NOTE: When planning an erasure coded pool, keep an eye on the `min_size` as it defines how many OSDs need to be available. Otherwise, IO will be blocked. -For example, an EC pool with 'k = 2' and 'm = 1' will have 'size = 3', -'min_size = 2' and will stay operational if one OSD fails. If the pool is -configured with 'k = 2', 'm = 2', it will have a 'size = 4' and 'min_size = 3' +For example, an EC pool with `k = 2` and `m = 1` will have `size = 3`, +`min_size = 2` and will stay operational if one OSD fails. If the pool is +configured with `k = 2`, `m = 2`, it will have a `size = 4` and `min_size = 3` and stay operational if one OSD is lost. To create a new EC pool, run the following command: @@ -583,22 +583,22 @@ To create a new EC pool, run the following command: pceveph pool create --erasure-coding k=2,m=1 ---- -Optional parameters are 'failure-domain' and 'device-class'. If you +Optional parameters are `failure-domain` and `device-class`. If you need to change any EC profile settings used by the pool, you will have to create a new pool with a new profile. This will create a new EC pool plus the needed replicated pool to store the RBD -omap and other metadata. In the end, there will be a '-data' and -'-metada' pool. The default behavior is to create a matching storage +omap and other metadata. In the end, there will be a `-data` and +`-metada` pool. The default behavior is to create a matching storage configuration as well. If that behavior is not wanted, you can disable it by -providing the '--add_storages 0' parameter. When configuring the storage -configuration manually, keep in mind that the 'data-pool' parameter needs to be +providing the `--add_storages 0` parameter. When configuring the storage +configuration manually, keep in mind that the `data-pool` parameter needs to be set. Only then will the EC pool be used to store the data objects. For example: -NOTE: The optional parameters '--size', '--min_size' and '--crush_rule' will be +NOTE: The optional parameters `--size`, `--min_size` and `--crush_rule` will be used for the replicated metadata pool, but not for the erasure coded data pool. -If you need to change the 'min_size' on the data pool, you can do it later. -The 'size' and 'crush_rule' parameters cannot be changed on erasure coded +If you need to change the `min_size` on the data pool, you can do it later. +The `size` and `crush_rule` parameters cannot be changed on erasure coded pools. [source,bash] @@ -609,7 +609,7 @@ pvesm add rbd --pool --data-pool If there is a need to further customize the EC profile, you can do so by creating it with the Ceph tools directly footnote:[Ceph Erasure Code Profile {cephdocs-url}/rados/operations/erasure-code/#erasure-code-profiles], and -specify the profile to use with the 'profile' parameter. +specify the profile to use with the `profile` parameter. For example: [source,bash] -- 2.39.2