I’m delivering a VMware View training this week. When I reached the “Replicate Server” chapter we had to do a lab with the “Hercules virtual appliance”. The goal of the lab is building a multiple “Connection Server” environment and let the appliance do the load-balancing. Although the “Hercules virtual appliance” is well documented and even has a VA page at the VMware website, I had a hard time to get it working. The virtual appliances available on http://istanbul.sourceforge.net/ either have a IDE disk or an old SCSI disk which isn’t compatible with ESX 3.5. I converted the “Hercules virtual appliance” to the Open Virtualization Format (OVF), and it’s available for download at the following address :
http://www.ntpro.nl/software/Hercules-SCSI-ESX3.zip
Here’s the way to set it up:
• Import the OVF virtual aplience.
• Power-on the Hercules VM.
• Open a console. Login as a user-ID of "root" with a password of "root".
• Enter the following command at the command line:
• pen 443 10.168.100.3:443 10.168.100.4:443
The format of the command is: pen <port-number> <first-server:port> <second-server:port>. There is a space between the first port number and the first server IP. There is a second space between the first server's 443 port and the second server's IP.
It runs on a Linux OS built from scratch to have a minimal footprint. It can run with just 32MB memory for normal usage and you can increase memory requirements for the appliance as you need. It also has a built in web server, SSH server, DHCP client. You can administer the machine remotely via SSH. It is setup for DHCP so the networking is setup automatically. A webserver is installed to both serve up this page and to help you test different configurations. The load balancing functionality is provided by the excellent open source project pen.
The amount of disk space used by it is 4.0 MB. The virtual disk will expand as needed and has a maximum size of 100 MB. This is the minimum size of a virtual disk that can be created in VMware Workstation. The compressed/zipped image of this appliance is 2.5 MB !