2. Staging a Debian Sarge Server

2.1 Create image using xen-tools

The <@@ref>xen-toolsxen-tools package make creating a new server trivial. This particular command creates a server with 8Gb/384MB RAM, which is more than enough to handle the monitoring of other local Xen environments. An enterprise server deployment for monitoring thousands of hosts is typically much larger. Expanding memory and disk dynamically after-the-fact is trivial, thanks to Xen. There are some defaults (gateway, location of disk images, default kernel, etc) that are stored in /etc/xen-tools/xen-tools.conf.

Create the system

nz-xen:~#xen-create-image --hostname=nz-mail --ip=172.1.1.23 --size=8Gb --memory=384Mb --swap=512Mb --dist=sarge

2.2 Boot up the DomU

DomU is the Xen term for a non-authortatitive virtual machine. Consider it like a fast version of a VMware workstation image.

nz-xen:~#xm create nz-mail.cfg

Check that it is running

nz-xen:~# xm list
Name ID Mem(MiB) VCPUs State Time(s)
Domain-0 0 88 1 r----- 359.0
nz-nms 1 384 1 ------ 11.9

Log in

nz-xen:~#xm console 1

or

nz-xen:~#ssh nz-nms

A note on Xen-Tools 'role' files: At Netstatz, we typically deploy our products in Xen environments, and much of the package instalaltion process covered in this document, with customizations, is contained within a ONMS-specific 'role' file.

xen-create-image --host=hostname --ip=x.x.x.x --role=nz-onms --dist=sarge.

Future versions of this document may have a step-by-step process for Sarge from cold iron, similar to the old Woody Staging, and possibly include more details on Xen staging, however it just recently entered unstable. There is enough information in the appendicies to get anyone familiar with apt-get source xen-3.0, dpkg-buildpackage -rfakeroot -uc -b and pinning preferences from backports.org. The great news is that everything Xen apt-get updates in Debian unstable, allowing a user to live-migrate their Sarge OpenNMS server to a Sarge Xen environemnt after the fact.

Use the Debian Sarge install CDs or DVD to stage a Debian server. Servers with a fast Internet connection should use the Sarge Minimal Network Install CD which is quick to download and supports most network cards. If you have any questions, there is lots of installation help online at the Debian Document Repository. Specifically the Debian Installation Guide is found here and provides detailed installation methedology.