Invariably, the client has set up a server using Ubuntu server edition or CenOS or some other Linux distribution. The base server choice is invariably a good one, but problems start to appear after going live and coming under load. These problems occur because the sysadmin who set up the server ignored a few simple rules:

1. Package managers are good for setting up generic systems. For small loads, packaged Apache is fine. But once you start to play with the big boys, you must be prepared to build Apache from scratch. Apache needs to optimized to your hardware and needs to be stripped of cruft that you don’t need.
2. Apache is a powerful server and is great for serving dynamic content. But if you have a lot of traffic, it can be overwhelmed trying to do too many things at once. Split the tasks and have a specialized, light-weight server like lighttpd server up your static content and leave just the heavy lifting for Apache.
3. Optimize your database, too. Don’t focus on just the webserving. If you’re getting data from MySQL, look carefully at how it’s set up. I’ll be covering this as a separate note soon.

In short, you need to look at all of the processes and individual components. Often, when I’m called in, decisions such as hardware and server software have already been made and I’m required to work within those constraints. But even with hands tied, there’s a lot of things that can be done to improve website performance.

snmp services on OpenSolaris are provided by a service called sma. To get snmp working on OpenSolaris:

$pfexec pkg install SUNWsmmgr

$pfexec svcadm enable sma

The configuration file is net-snmp standard stuff, but it’s concealed in /etc/sma/snmp/snmpd.conf. After changing this file, restart sma:

$pfexec svcadm restart sma

OpenSolaris will now respond as normal to snmpwalk requests from your monitoring system.

By the way, pfexec is the OpenSolaris equivalent (roughly) to sudo on Linux. It allows you to execute commands as root. The first account created, by default, is allowed to execute pfexec against all OpenSolaris commands without requiring a password. A future note will tell you how to change that…

Sun Fishworks aims to bring large volume NAS and SAN storage down to commodity pricing. They’re combining a lot of their different technologies and playing on all their strengths—most notably, Solaris. By combining the power of Solaris with low cost hardware, Sun is challenging companies like NetApp. With any luck, they’ll be able to pull it off from a marketing standpoint—an area of weakness at Sun.

The Fishworks philosophy is a great one—do more with less. I brought this home by building a NAS server for the house based around OpenSolaris and the MSI Wind PC.

OpenSolaris is installed on a 4 GB Compact Flash card that sits on the Wind PC’s motherboard. There are 2 500 GB hard drives—one in the hard drive bay and one in the optical drive bay via a 5.25 to 3.5 adapter. There is no optical drive. In this configuration you can install OpenSolaris via a USB optical drive or, like I did, via a USB thumb drive.

Once installed, the two disks are placed into a ZFS pool and, in my case, mirrored. It’s amazing how flexible and easy ZFS is to manage, particularly with the power it gives you. CIFS is now an in-kernel driver on OpenSolaris and managed via ZFS settings. Sharing volumes and directories is easy. Even NFS sharing for the Linux boxes on my network is a no-brainer.

I’m still tweaking and testing system performance, but once I’m done I’ll do a full writeup on the system. So far, it’s good, fast and cheap. Not bad at all…

When you’re forced to work on a Unix infrastructure on a Windows desktop, the very first tool you want is an ssh client. I’ve long used PuTTY for this. It’s an excellent tool and has all the bells and whistles that I need: certificate management, port forwarding, configurable terminal, screen support, etc. It has a couple of quirks that I don’t like, the most notable being that it stores its saved settings in the registry so it’s difficult to move saved settings from one machine to another. That’s not a show stopper, but as I’ve expanded my Windows work lately it became a real annoyance. I’ve been configuring multiple Windows machines for sys admin work and having to reenter the servers on every machine is a pain.

I took a look around at the state of Windows ssh tools and found a couple that looked really nice. I played around with them and enjoyed things like separate configuration files that are easily transportable. Some had built in scp clients. All were good, solid tools.

But I’m back to PuTTY. Despite not being updated since early 2007, PuTTY is still a solid tool. It’s memory footprint is small. It’s easy to install. It’ll run in a standalone USB key environment. There’s now a Linux version, though I’ve not used it. It just works. Every time. With no futzing about. It’s old, stodgy and very, very reliable. It is the best ssh client for Windows.

Two additional points: if you need scp, the PuTTY scp client works, but it’s not got a lot of features. Try WinSCP instead. Secondly, when is Microsoft going to get with the program and put an ssh client directly into the Windows shell? Being able to run “ssh -l 8080:remote:8080 -X somemachine.com” directly from the command line is, for me, more intuitive and easier to do. One of the drawbacks of being a crotchety old Unix admin.