Bug 1321896

Summary: [Doc RFE] Document Block Device Mirroring in Block Device Guide
Product: Red Hat Ceph Storage Reporter: Anjana Suparna Sriram <asriram>
Component: DocumentationAssignee: Bara Ancincova <bancinco>
Status: CLOSED CURRENTRELEASE QA Contact: Hemanth Kumar <hyelloji>
Severity: high Docs Contact:
Priority: high    
Version: 2.0CC: hnallurv, kdreyer, ngoswami, nlevine
Target Milestone: rcKeywords: Documentation, FutureFeature
Target Release: 2.0   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2016-09-30 17:22:10 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Anjana Suparna Sriram 2016-03-29 10:49:22 UTC
Additional info: Document replicating or mirroring a Ceph Block Device image on one cluster/pool to another cluster/pool, primarily for disaster recovery.

Comment 7 Hemanth Kumar 2016-08-07 19:35:10 UTC
Following are my observations while verifying the doc, Please modify the doc as mentioned below..

In the Configure Mirroring Section :
https://access.qa.redhat.com/documentation/en/red-hat-ceph-storage/2/block-device-guide/#configuring_mirroring

1.
=> One block device client is connected to each of the clusters: client.master and client.slave. For information on installing Ceph clients, see the Client Installation chapter in the Installation Guide for Red Hat Enterprise Linux. 

 -- the keyring should be in the format "master.client.master.keyring" - with only client.master and client.slave rbd fails with cephx authentication.
We need to create a new cephx authentication.

2.
=> On both client hosts, install the rbd-mirror package:

# yum install rbd-mirror

 -- We have to install "ceph-common" and also copy the admin keyring to the Client host. Please mention about that.
Update the same for Image configuration also

3.
=>  Add the clusters as peers:

$ rbd mirror pool peer add data client.slave@slave --cluster master
$ rbd mirror pool peer add data client.master@master --cluster slave

 -- This section should be moved after enabling the pool mirroring
This fails as the pool needs to be enabled first.
Steps 4 & 5 should to be interchanged both in Pool and Image configurations.


4.
=> Configuring Image Mirroring
On both client hosts, enable and start the rbd-mirror daemon: 

 -- Add one more command to make the daemon start by itself after rebooting
# systemctl enable ceph-rbd-mirror.target


= > The stack pool on the master cluster contains the image1 and image2. Journaling is enabled on the images. See Enabling Journaling for details. 

 -- The name of the pool mentioned in prereq is "stack" but the syntax and examples contains pool name as "data".

Comment 9 Hemanth Kumar 2016-08-11 17:20:46 UTC
Looks good to me..
Moving to Verified state.