Configuring a PXE server to present the files and information needed for kickstarting your ESX hosts isn’t too difficult a task. It does require some basic unix/linux knowledge, but aside from that, not too bad. I use a CentOS virtual machine with just 256 MB of RAM (you’ll need at least 512 for a GUI, but one isn’t necessary) to act as the PXE server for my ESX hosts. This same virtual machine also serves as a management point, as it has access to the management lan and with the perl toolkit and rCLI installed I can automate much of the work I need to accomplish with the hosts.

I happen to segregate the different types of traffic on the ESX hosts onto different VLANs. This means management (COS/PXE), VMotion, IP Storage, and virtual machine traffic (usually several VLANs by itself) are all separate. It is important that the server (or virtual machine) that you are using is configured with at least one interface on the same VLAN/network that the ESX management network is on. That interface will also need to have a static IP address.

It is also important that DHCP is able to function on this network when the host is in a totally unconfigured state. This means if you are trunking to your ESX hosts you must have the native VLAN set to the same as your management VLAN and port channeling (802.11q / LACP) can not be turned on during the PXE process.

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I confess… Sometimes I just need Linux. I’ve tried everything from live disks to running an “Administrative” VM.  The main problem with all of them is the break. What would take 5 min if I could do it from within windows, takes 30min and destroys my thought process along the way.   There are tools that I can run from within windows.  Unfortunately most of them either suck or cost too much.  I don’t have room for another PC/thin client at my desk, and I’m NOT giving up my Vista rig… What to do?

Enter DSL (Damn Small Linux) I stumbled upon this little treat on accident a couple weeks back. They have many versions available and I’ve played with several, but the QEMU VM is simply brilliant.

Not only is It easily configured, but the dang thing just works.  Now when I need to modify a config file on a NetApp, or fix a VMX. I fire up DSL, it launches as a windowed app (on my vista x64 rig!).  90 seconds later I’m logged in and continue working, NO break in work flow!

Couple disclaimers: I still hate it, and think it is beyond legacy, but there is no fighting it anymore. Some form of UNIX will always be in the data center.  So for now I’m using DSL to fill that gap…  Got a better solution?

~Glenn

Ok, so the title is a little misleading. Configuration Management is a part of ITIL, however I’m not going to talk about ITIL, at least not directly.

As an administrator I’m responsible for multiple systems. Some of these are identical, e.g. Apache servers, MySQL servers, some of them provide unique, stand alone, services. However, they all have some things in common…sshd configuration, log rotation schedules (logrotated), etc.

It’s a PITA to keep up with all of these servers individually. A global change can take quite a bit of time, especially with our ever increasing number of ESX hosts. So, how do I make my job easier, myself more productive, and next year’s raise larger? Automated configuration management.

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I’ve previously mentioned that I use Fedora 8 on my laptop at home. It is a Core 2 Duo Dell with a GeForceGo 7300. Originally, it had Vista Home Premium, and I really did give Vista a chance (for almost 8 months!!), but I just like linux more. I do still have to go back to Vista on the (extremely) rare occasion I need bluetooth support. For some reason I can’t get the integrated bluetooth modem to work with Fedora. The GeForce Go has caused me nothing but problems. Nvidia’s normal drivers won’t work with the Go series from Dell, I have to get the drivers directly from Dell…and they are flaky.

Anyway, I recently reloaded my laptop and let it update everything to the newest available. Unfortunately, at some point, suspend stopped working. I’m not sure when it was (it applied ~ 300 updates), but it stopped. Well, it didn’t exactly stop working…it still suspends, once, after which the monitor refuses to work. I can still ssh in, and everything seems to be functioning normally, but the monitor doesn’t work. Which makes a laptop very useless.

So, since I’ve reloaded linux a number of times, and it seems each time I forget what I did to fix it, I’m documenting it for myself, and posterity.

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