rook: defining the first step

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Nico Schottelius 2022-09-03 17:11:14 +02:00
parent bcc155c1fd
commit 6e69a121de
1 changed files with 67 additions and 0 deletions

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@ -424,6 +424,7 @@ For migrating, we don't want rook in the first stage to create any
OSDs. So we will replace `useAllNodes: true` with `useAllNodes: false`
and `useAllDevices: true` also with `useAllDevices: false`.
### Extracting a monmap
To get access to the existing monmap, we can export it from the native
@ -459,6 +460,71 @@ In this particular cluster we have 2 pools:
The device class "hdd-big" is specific to this cluster as it used to
contain 2.5" and 3.5" HDDs in different pools.
### [old] Analysing the ceph cluster configuration
Taking the view from the old cluster, the following items are
important for adding new services/nodes:
* We have a specific fsid that needs to be known
* The expectation would be to find that fsid in a configmap/secret in rook
* We have a list of running monitors
* This is part of the monmap and ceph.conf
* ceph.conf is used for finding the initial contact point
* Afterwards the information is provided by the monitors
* For rook it would be expected to have a configmap/secret listing
the current monitors
* The native clusters have a "ceph.client.admin.keyring" deployed which
allows adding and removing resources.
* Rook probably has a secret for keyrings
* Maybe multiple depending on how services are organised
### Analysing the rook configurations
Taking the opposite view, we can also checkout a running rook cluster
### Configuring ceph after the operator deployment
As soon as the operator and the crds have been deployed, we deploy the
following
[CephCluster](https://rook.io/docs/rook/v1.8/ceph-cluster-crd.html)
configuration:
```
apiVersion: ceph.rook.io/v1
kind: CephCluster
metadata:
name: rook-ceph
namespace: rook-ceph
spec:
cephVersion:
image: quay.io/ceph/ceph:v14.2.21
dataDirHostPath: /var/lib/rook
mon:
count: 5
allowMultiplePerNode: false
storage:
useAllNodes: false
useAllDevices: false
onlyApplyOSDPlacement: false
mgr:
count: 1
modules:
- name: pg_autoscaler
enabled: true
network:
ipFamily: "IPv6"
dualStack: false
crashCollector:
disable: false
# Uncomment daysToRetain to prune ceph crash entries older than the
# specified number of days.
daysToRetain: 30
```
We wait for the cluster to initialise and stabilise before applying
changes. Important to note is that we use the ceph image version
v14.2.21, which is the same version as the native cluster.
## Changelog
@ -466,6 +532,7 @@ contain 2.5" and 3.5" HDDs in different pools.
### 2022-09-03
* Next try starting for migration
* Looking deeper into configurations
### 2022-08-29