Diary of a Network Geek

The trials and tribulations of a Certified Novell Engineer who's been stranded in Houston, Texas.

4/16/2008

What’s on your monitor?

Filed under: Fun Work,Geek Work,Linux — Posted by the Network Geek during the Hour of the Monkey which is in the late afternoon or 5:59 pm for you boring, normal people.
The moon is a Full Moon

What do you run on your monitor server?

Do you think you’re too small to run a monitoring server? Well, I have two local servers, a remote web server and a remote e-mail server that I’m in charge of worrying about and I run a monitoring server. It’s not much of a server, really, just an old workstation to which I added a bunch of spare memory and a large, clean hard drive. Naturally, I run Linux on my monitoring server, which, ironically enough, I named Monitor. Specifically, Monitor runs Red Hat Fedora.

Monitor runs Nagios, which I’ve mentioned before. With Nagios, I monitor both my main file server and my accounting SQL server. I also watch the off-site web server and the SMTP and POP3 e-mail services on the managed e-mail server we have through our ISP, just to make sure they’re up and running. (It’s a long story on why we have that, but, rather than run my own, to reduce hassle, headache and potential disaster, I let someone else worry about it.) Nagios tells me the status of drive space, the memory usage, the CPU usage and uptime on both servers. On the accounting SQL server, it verifies that the SQL service is available and that users can log into it. On the file server, it tells me the status of the Backupexec modules. Unfortunately, I haven’t figured out a way to get Nagios to tell me more than the running status of Backupexec, but, in my spare time, I still try to find a way to have it report the status of the last backup or restore job run. No joy yet, but I keep trying.

I also have a browser window open to the SolarWinds installation at our ISP. They monitor inbound and outbound traffic over the Internet connection we have. Usually, I keep a window open on the standard “interface details” reports which update regularly. Most of the time, I also open a window to the weekly history report on the min/max/average packets in and out. I have to update that manually, but it lets me quickly compare today’s traffic to network traffic for the past week. It’s nice to see those trends!
Lately, I’ve been keeping a browser window open to the national weather forecast, by hour, for our local area. In hurricane country, keeping track of the weather can be vitally important! But, if you live in snow country, the same thing would probably be true, too. I don’t recall heavy snow causing an outage during my time up North, but it’s not out of the realm of possibility.

Finally, I almost always have Wireshark running a packet capture, too. If I see a sudden spike in traffic, having a packet capture already running could make a big difference. I have that capture set to save files locally, too, just in case. I’ve been setting the capture to rotate nine files and to keep the files at seven megabytes each. That should give me a pretty good spread of captured network data if I ever need to go back and diagnose a traffic problem. And, since the machine is actually kind of stinky hardware and crashes on occasion, when I restart the packet capture, I rename the base file using the current date. That way, I can tell at a glance when the capture was started.

One day, I’d like to move this all to another machine that’s more stable, faster and has more drive space, but, until then, this works. It’s only on the private network, so I can’t look at it directly from the Internet, but, it still does enough for me. One of these days, I’ll look into some of Nagios’ data presentation modules and teach this old dog a few new tricks, like automated uptime reports and that kind of thing.

Hopefully, that hasn’t bored too many of my non-geek readers. And, I hope it’s given my geek readers something to think about. So, tell me in the comments, if you have a monitoring server/station/whatever, what does it run? If you don’t have one, why not?

4/2/2008

WordPress Version 2.5

Filed under: Criticism, Marginalia, and Notes,Fun Work,News and Current Events,Personal,Red Herrings — Posted by the Network Geek during the Hour of the Tiger which is terribly early in the morning or 5:34 am for you boring, normal people.
The moon is a Full Moon

You may have noticed a few very minor cosmetic changes.

That’s because I upgraded the blog to the new version of WordPress Monday night.
I have to admit, I’ve been eager for the upgrade because I’ve been a little behind on that. With all the antispam plugins I was running, though, I never really had a security problem. I did have to fix a couple of plugins and replace one. You’ll notice, for instance, that the titles are a bit different. That’s due to a plugin not working with the new version and being replaced. Other changes are all behind the scenes, but involved editing other people’s ancient, and no longer supported, plugins to work with the new version. The Time Of Day plugin, which shows you, roughly, what time of day I posted something, was one of those that I had to edit a bit.
Sadly, one very good plugin, Bad Behavior, just simply had to be turned off for now. I hope the author updates it soon for the new release of WordPress, because it’s very, very good.

Now, I just have to update all my other blogs…

3/28/2008

Free Resources

Filed under: Criticism, Marginalia, and Notes,Fun,Fun Work,Geek Work,Red Herrings — Posted by the Network Geek during the Hour of the Tiger which is terribly early in the morning or 5:37 am for you boring, normal people.
The moon is a Full Moon

I love free.

One of the things people don’t talk about when you’re going through an extended medical illness is how to pay for what’s not covered afterward. I’m working through that, and doing my best to work toward being debt free. And, in thinking about that, it brought to mind all the free things I can get on the web. The software I run this blog, and others, with is free, for instance. A little searching around can turn up all kinds of free things.

While doing a little search, I found three lists of free resources over at Lorelle on WordPress.
Designing a Rainbow – free resources for color and design.
Blogging Tips – Hundreds of free resources for finding content for your blog.
and HTML, CSS, PHP, and More free cheatsheets

All three are lists of great resources for your website or blog. If you can’t find something useful in at least one of them, you’re not trying!

3/21/2008

Linux Home Server HowTo

Filed under: Fun,Fun Work,Geek Work,GUI Center,Linux,The Network Geek at Home — Posted by the Network Geek during the Hour of the Tiger which is terribly early in the morning or 5:41 am for you boring, normal people.
The moon is a Full Moon

So, you want to build your own Linux server for home?

Okay, you’ve seen me write about it and many of you think it’s too geeky to do on your own, but I swear to you, it’s not. In fact, here is a list of easy howto sites:

Who needs Windows Home Server with Linux around?
Linux Home Server HowTo at LinuxQuestions.org
Build It: Linux Home Server
The Australian Linux HowTo

And maybe, just maybe, when I finally get around to doing this on my home network, I’ll write up some documentation on how to do it. Or, at least, how I did it.

3/6/2008

Default Passwords

Filed under: Fun Work,Geek Work,The Dark Side — Posted by the Network Geek during the Hour of the Hare which is terribly early in the morning or 6:25 am for you boring, normal people.
The moon is a Full Moon

Why you should always change default passwords…

I don’t always agree with the bloggers over at TechRepublic when they insist that they have the five or ten most important links on a subject, but, every once in a while, they get one that’s really good. I can’t say much about most of the links in Chad Perrin’s post, Five must-have security resources, but his link to the RedOracle Default Password list is great! They have default passwords for just about everything there and, while that might not mean much to all my readers, if you have to do an emergency reconfiguration on something and take it back to the manufacturer default, having that password can really simplify your life.

Also, since these are so well documented, it’s a good illustration of why the first thing you should do after configuring, or reconfiguring, something is to change the default password.

2/29/2008

Bandwidth Usage

Filed under: Fun Work,Personal,Red Herrings,The Network Geek at Home — Posted by the Network Geek during the Hour of the Sheep which is in the early afternoon or 2:05 pm for you boring, normal people.
The moon is a Full Moon

I’m a resource hog.

One of my several websites has used 5856.36 megabytes of 6500.00 megabytes of bandwidth as of 13:55 today. Do you think it will make it until midnight when the counters reset?

2/27/2008

Review: Building a Monitoring Infrastructure with Nagios

Filed under: Fun Work,Geek Work,Linux,Review,Things to Read — Posted by the Network Geek during the Hour of the Tiger which is terribly early in the morning or 5:47 am for you boring, normal people.
The moon is a Full Moon

Well, since I bought it, I think I should review it.

So, I’ve been wrestling with the typically mediocre documentation which surrounds most OpenSource projects and, in an effort to ramp up my efforts, I bought Building a Monitoring Infrastructure with Nagios by David Josephsen. Now, keep in mind that I don’t normally read entire computer books very much any more, but rather read just the few chapters that seem most relevant to my current project and keep the book for future reference. Also, I was in a hurry when I bought this book and didn’t have time to look at it very closely before purchase.

Now, all that being said, this book wasn’t all that helpful to me. It probably would have been a great help if I’d gotten it right when I was starting to install Nagios, though. Sadly, I puzzled out most of what I needed to know about the system the hard way, via on-line help files, how-tos, and trial and error.
With a table of contents broken up into eight chapters, titled; Best Practices, Theory of Operations, Installing Nagios, Configuring Nagios, Bootstrapping the Configs, Watching, Visualization, and Nagios Even Broker Interface, you can see that this book is about installing the base system and monitoring the most basic of services. I got the book hoping to monitor an SQL database and, if possible, the completion status of backups. Sadly, that’s not covered in this book. I did manage to find more information on-line regarding the SQL database monitoring, but not about watching backups.

So, mostly, this book didn’t get done what I was after. However, since there are things wrong with my installation, I may save the configuration files, wipe the server and start over, following the principles laid out in this book. For instance, I can’t seem to get scheduled down-time set via the web interface on my installation, which should be possible by default. And, the visualization on my monitoring server leaves something to be desired, so, if I start over, I’ll reference the chapter on Visualization. Certainly, it would be nice to start from a clean slate and do it right, but I may not have time to do that. We’ll see.

In short, Building a Monitoring Infrastructure with Nagios was a bit of a disappointment for me, but not because it wasn’t a good book. Rather, by the time I bought this book, I was a little past implementing most of the strategies discussed. Again, though, if I end up starting over, which I may, I’ll definitely read more of this book to get it done the right way.

2/7/2008

Review: Nagios

Filed under: Career Archive,Fun Work,Geek Work,Linux,MicroSoft,Novell,Ooo, shiny...,Review — Posted by the Network Geek during the Hour of the Tiger which is terribly early in the morning or 5:27 am for you boring, normal people.
The moon is a Full Moon

I don’t think I’ve mentioned this before.

Some time ago, I was having problems with traffic on my network. Something, somewhere was apparently causing some issues with bandwidth on our Internet connection. Or, at least, that’s what our ISP kept telling us. It was, I think, the excuse they were using to avoid dealing with an e-mail problem.
Regardless, I had to find a tool to monitor our network traffic. I ended up using Wireshark for that, but along the way, I discovered a number of OpenSource monitoring tools for various purposes. The one that impressed me the most was Nagios.

Nagios is, according to the opening paragraph on their website, “an Open Source host, service and network monitoring program.” While I never did configure anything to monitor the network, per se, I did configure this to watch both local servers and third-party web and mail servers.
First of all, it’s important to know that Nagios runs on Linux. So, to install the software, you first have to have an available Linux server on which to install it. I’m using an old workstation that I installed the latest version of Fedora, the free version of RedHat. Getting the initial install done wasn’t very hard at all. In fact, there were RPMs available, so all I had to do was use RedHat’s package manager to get the base install loaded on the machine.

After the initial software load, I mainly followed the Quick Install instructions that they link to on the first page. Then, since I was mainly monitoring Windows servers and workstations, I found the cleverly titled help page, “Monitoring Windows Machines“, and followed that. This page ran me through the basics of installing the NSClient++ on a Windows machine and configuring Nagios to connect to and monitor that client. One thing that I had to find out the hard way was that the entries for the monitored systems have to be duplicated for each host. In other words, there is no way to just list all the Windows systems you want to monitor. You have to created entries describing each host individually. That’s not a big deal, honestly, since you can open the configuration files in a text editor and just copy, paste and edit the required entries.
I did have a few false starts here, until I figured out the correct syntax and the fact that every host has to be part of a previously defined group. But, other than that little glitch, configuration was fairly simple.

It took a little more digging, but I later found instructions for passively monitoring services running on servers without a client. I now use my private installation of Nagios to monitor our company webserver, both POP3 and SMTP on our hosted e-mail server, as well as my two Windows 2003 servers. I can even check on the Microsoft SQL database, thanks to information I got from this post on the OSdir mailarchive. And, did I mention that all this software was free? Yeah, the documentation wasn’t the best and it took me a little while to figure out the install and config, but it was far easier than the other monitoring software I played with and I can let anyone who has the username and password check these stats from their own workstation via a web browser. How cool is that? Oh, and did I mention that this can be used to monitor Linux/Unix systems, Windows systems and even Netware systems? Nagios pretty well covers it all!
(Oh, and as a side note, if you’re messing around with the configuration and want to reset the statistics, just stop the service and delete /usr/local/nagios/var/status.dat, then restart the service. All your counts will zero and all the checks will start fresh.)
In short, if you’re looking for a low-cost but versatile monitoring system and aren’t afraid to read the documentation, I highly recommend investigating Nagios.

1/31/2008

No, Thank You, Mr. Spammer

Filed under: Criticism, Marginalia, and Notes,Fun,Fun Work,News and Current Events,Personal,Red Herrings — Posted by the Network Geek during the Hour of the Hare which is terribly early in the morning or 6:21 am for you boring, normal people.
The moon is a Full Moon

As a result of my ranking in Google, I occasionally get silly spam.

This morning, for instance, I got this e-mail:

Let me know if you’re looking to get a higher listing with search engines. I can send you the details first, just let me know how you would like to communicate.
Sincerely,
(insert marketer’s name here.)

I responded with:

Higher than what? I’m already the number one hit on Google for Network Geek. After all, how was it that you found me to try and sell to me?

No, thank you, but I enjoy doing it myself.

Sincerely,
Jim Hoffman

I mean, really, half the fun of having this site and doing this blog is that I use it to manipulate one of the biggest search engines ever!  Ah, well, maybe if he’d actually read my blog, he’d know that I made most of the money I paid my divorce lawyer back optimizing his site for the search engines and getting him connected with an URL submission service.

Silly spammers.

1/30/2008

Linux Imaging – Update

Filed under: Criticism, Marginalia, and Notes,Fun Work,Geek Work,Linux,MicroSoft — Posted by the Network Geek during the Hour of the Tiger which is terribly early in the morning or 5:20 am for you boring, normal people.
The moon is a Full Moon

So, I figured it was about time for another hardcore geek post.

I’ve been using the Linux-based imaging solution that I detailed here and here for quite a few weeks now. Mostly, it’s been going very well.
Okay, once I figured out it was better to start with a small drive partition as my base system, from which I created the standard image, the process got easier. The thing is, it’s always easier to start with a small partition and then use tools built into the Knoppix live cd to grow the partition larger than to try and shoe-horn a big disk partition onto a small disk. And, by “easier”, I mean it’s the only way to do it. I spent quite a bit of time trying to make it work the other way, but I never did. On the other hand, starting with an image based on a 30 gigabyte or less partition then expanding it to fit a 150 gigabyte hard drive has worked just fine.
Incidentally, I used a bootable gparted cd to make that change.

Also, I had a small problem with a particular Intel motherboard chipset. Specifically, it was the Intel 965 chipset, and the problem may effect other motherboards. In short, the problem was that Knoppix didn’t see the SATA drive to mount it. If Knoppix can’t see the drive, it can’t image it or take an image from it. Luckily, there is a work around. If you’re using my method to image WindowsXP machines running the Intel 965 chipset, ensure the BIOS is set to AHCI. To do that, get into your system’s BIOS and go to Advanced > Drive configuration > Configure SATA as AHCI. Then, when booting into Knoppix, hit F2 and use the following command-line to boot:
knoppix 2 all-generic-ide pci=nommconf
This will start Knoppix in text-only mode, so you can run everything from there instead of opening up a terminal session.
After you put the image on the fresh machine, you need to ensure the BIOS is NO LONGER set to AHCI. To do that, get back into your system’s BIOS and go to Advanced > Drive configuration > Configure SATA as IDE. After reconfiguring the BIOS, you can boot into the new Windows XP clone and proceed as I’ve already described in the other posts.

Oh, one last thing on this…
I kind of cheated on reimaging machines in text mode with that Intel 965 chipset.  Because the tools I used to resize NTFS disk partitions were all GUI based and XWindows was having a problem running on those Intel 965 boards, I installed one machine from scratch and just grabbed the larger partition table and master boot record.  Then, when I made the new machines, I just used the larger partition and MBR images to get everything out of the disk.  I still used the smaller data disk partition images, but I used NTFSResize to expand the NTFS partition to fill the disk.  Worked like a charm.

Anyway, I apologize to my non-geek readers, but, hey, I am a professional network geek and I love this stuff.  I think I strutted around for a full five minutes after figuring out that set of little tricks the same afternoon.  Of course, it wasn’t long before some other stupid thing brought me right back to reality, but that couple of minutes where I was the king of the world, network geek genius extraordinaire, made it all worthwhile.

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