A VMware vCloud Director (vCD) cluster contains one or more vCD servers, these servers are referred to as “Cells” and form the basis of the VMware cloud. A cloud can be formed of multiple cells.
This diagram is a good representation of the vCD Cluster concept.
To enable multiple servers to participate in a cluster, the same pre-requisites exist for a single host as for multiple hosts but the following must be met:
- each host must mount the shared transfer server storage at $VCLOUD_HOME/data/transfer, this is typically located in /opt/vmware/cloud-director/data/transfer.
This shared storage could be a NFS mount, mounted to all participating servers with rw access for root. It is important that prior to configuring the first server, a decision must be made on whether a cluster is required. If you intend to use a vCD Cluster, configure the shared transfer server storage before executing the vCD installer.
Check out the vCloud Director Installation and Configuration Guide for pre-requisites.
Shared Transfer Server Storage
For this post, I’ve setup an NFS volume on Freenas and given rw permissions for all cluster members to the volume. It is assummed that you have a completely clean installation of RHEL 5 x64 (or if like me you are running this in a lab CENTOS 5 x64), with all the latest updates and pre-requisite packages.
Now to mount the volume on all hosts:
- Connect to your first host using SSH or login directly
- Edit your /etc/fstab file and add the following line remembering to change to your NFS server and relevant mount point
- vcd-freenas.vmwire.local:/mnt/SSD /opt/vmware/cloud-director/data/transfer nfs rw,soft,_netdev 0 0
- The resulting /etc/fstab should look something like this:
- Now create the shared transfer server storage folder structure, /opt/vmware/cloud-director/data/transfer (just do a mkdir command)
- run chkconfig netfs on
- Repeat steps 1-6 for any other hosts
- Restart servers
Now you are ready to install vCD onto the first host, making sure that you have met all the pre-requisites as detailed in the vCloud Director Installation and Configuration Guide. Once completed you should have a working cell with its shared transfer server storage folder located on the NFS volume.
Setting up a second cell as part of the Cloud Director Cluster
At this point you should already have a working cell with the vCD shared transfer server storage located on the NFS volume. Before you install vCD onto a server the following must be done:
- All pre-requisites for a single server installation must also be met for subsequent servers as part of a vCD Cluster
- The second server must also have rw access for root to the shared transfer server storage
- The second server must have access to the response file, this file is located in /opt/vmware/cloud-director/etc/responses.properties on the first successfully installed server
- Copy the above file to the second server or to the shared transfer server storage
- It is important to note that the response file contains values that were used for the first server. Subsequent servers will use the response file, and as such if you stored your certificates.ks file for the first server in a location not recognised by subsequent servers, you will be prompted by the installation script to enter the correct path to the certificates.ks file for any subsequent servers. To avoid this, you could create all the certificates.ks files for all cluster members and place them in the shared transfer server storage, with of course unique names such as vcd-cell1-certificates.ks and vcd-cell2-certificates.ks.
- You can now install vCD onto subsequent servers with the command vmware-cloud-director-1.0.0-285979.bin -r /opt/vmware/cloud-director/data/transfer/responses.properties
The installer will automatically complete most prompts for you, but you will still need to select the correct eth adapter for the http and consoleproxy services, everything else will be automatic.
Go ahead and have a play and maybe even deploy a load balancer on top.
Here’s a screenshot of my two cells working side by side connecting to the same shared transfer server storage, oracle database and managing the same vCenters.
For more information read the overview at Yellow Bricks which also includes links to the product pages.