May 11

Server Names

By linc Hardware, Humor, work No Comments »

It has certainly been a while since I last posted, so I thought I would find something either interesting or funny to get things going here again. This happens to be funny (I think). I came across this tidbit of information I wrote at work some time ago and thought I would share.

Retired Server Names
Much like sports jersey numbers, some server names are never to be used again… Mostly because they appear to be secretly cursed.

Trinity
I am not sure if there is some sort of bad mojo associated with naming a server with some kind of Godly connotation, but this VMWare GSX server would crash violently almost once an hour at its peak. As far as I know, nobody ever found out what the problem was, and after the name was changed it started working admirably.

Kashmir (pronounced “Cash-mere”)
This was an old RHEL 3.9 or AS 2.1 server that would crash almost as fast as you could start it back up again. We called this server “Crashmere”. The reason I am not sure of the OS level is it was hard to keep it running long enough to check. In it’s defense, I believe it had bad HDD’s before it was finally decommissioned, however, we were too paranoid to try reusing the hardware whether or not we attempted to fix it first.

Odessa
Odessa was, for the most part, our entire early implementation of an Identity Management System. It was based on an out of date and buggy Opensource LDAP and some poorly written custom code from some interns. Consequently it quickly became widely used and relied upon, and never updated as a result. Literally, this was the *beast* the infrastructure team worked to keep fed and happy. Eventually, we moved to a different IDM environment and Odessa was retired, the name never to be used again because we never want to see another single machine gain that much power over anyone again. Odessa is surely the precursor to Skynet.

Guarulhos
This is obvious – Just try and say the name. This is the reason one member of our team is never EVER allowed to pick server names again. We spent over a month trying to pronounce this in conversation until we finally gave up and changed the name outright.

Those are all the good ones I have right now but I am eager to hear any that any of you may have to contribute. Perhaps we could start some master list somewhere and save ourselves and others the tragedy of stumbling upon the reuse of one of these cursed names. :-)

Mar 17

Updates

By linc Linux Mint, RedHat, work No Comments »

updates

updates


i just love cssh. This is the way updates should be run.

Feb 04

UnixPorn

By linc Linux, work 4 Comments »

Todays desktop

Todays desktop


I don’t know why, but I have always been fascinated by what people have on their desktops and how they have them configured. Well, today I ran into a link to a site I hadn’t visited in a long time, and that is Unixporn. No, it’s not porn, it’s a bunch of people sharing how cool their desktop looks. Eye candy. Anyhow I thought I would post my desktop so far today. I’d put it on the Unixporn site, but hey, then what would I post here? :-) Show us all what your desktop looks like!

Addendum: I probably should mention what is actually running there. Gnome, Nautilus, xterms using vim for programming, transparent gnome-term running mocp for music, thunderbird email, pidgin instant messaging, and google chrome for browsing.

Nov 24

Ugly Sweater Day

By linc Humor, work No Comments »

uglysweater
For quite sometime, as a little morale booster, we have been having Hawaiian Shirt Fridays at work. It’s fun and I, personally like Hawaiian shirts. The gaudier the better.

Well, recently, it has been decided that in lieu of the warmer weather, perhaps we should temporarily switch to Ugly Sweater Fridays instead. What you see included in this post is my first attempt. I asked my wife the day before to run to the thrift store and get me the ugliest sweater she could find.

She really deserves the credit here, although I did wear it proudly. I was *easily* given the title for the most hideous sweater. We’ll have to see what happens next week, but I believe this will be hard to beat unless someone finds one of those light-up Rudolph holiday sweaters.

Let’s see the pics of YOUR ugly sweaters!

Nov 21

Linux to the rescue again

By linc Linux, Ubuntu, work No Comments »

I have to keep a windows xp vm kicking around that I use almost never for those nagging few windows apps that the smart developers didn’t make at least a web version for. Well, I needed to to some modifications to a project on MS Project server (Firefox/Linux compatibility in next release BTW) so I fired up the xp vm to find that it was effectively out of disk space. Back when I built it 2+ yrs ago I only made it an 8gb vm and with all the little proprietary apps over the years is has just gotten full.

A quick google search on the subject showed that I could, indeed, increase the drive space in the vmdk with the “vmware-vdiskmanager” command (vmware serer 1 – I told you this vm was old). I simply went to my virtual machines directory (where the vmdk files are stored) and issued “vmware-vdiskmanager -x 12gb -t 1 winxp.vmdk”. This says (-x) extend the volume to 12gb and that the volume type (-t 1) is split into the 2gb files. The command did it’s job in just a few seconds and presented me with a warning that I would need a third party program in the virtual machine to expand the partition there to get use of the new volume free space.

I learned from my favorite windows admin that there is a diskmanager utility in xp that *can* do this, however, not on the system partition, which is what I needed. I just happened to have an Ubuntu 9.10 iso handy and told the xp vm to boot that up instead. From there I started up GParted and quickly told it to extend the size of the partition to fill all the remaining free space on the volume. I clicked on the green checkmark to tell GParted to “Go” and off it went. The entire resize for GParted took only maybe 10 seconds. It’s just amazing to me. I remember when Linux couldn’t even figure out what an NTFS partition and here I was fixing one in mere seconds.

Needless to say, only a minute later I had my windows xp vm booting up and working in it’s newly extended NTFS partition. Once again, Linux saved the day!

Nov 13

Throw some Rocks at it!

By linc CentOS, Linux, RedHat, Science, System Administration, VMware, work No Comments »

ganglia
One of the parts of my day job is dealing with and managing our HPC cluster. This is an 8 node Rocks cluster that was installed maybe a week after I started. Now I was a bit green still at that point and failed to get a better grasp on some things at the time, like how to maintain and upgrade the thing, and I have recently been paying for that :-)

Apparently, the install we have doesn’t have a clear-cut way to do errata and bug fixes. It was an early version of the cluster software. Well, after some heated discussions with our Dell rep about this, I decided what I really needed to do was a bit of research to see what the deal really was and if I could get us upgraded to something a bit better and more current.

Along came my June 2009 issue of The Linux Journal which just happened to have a GREAT article in it about installing your very own Rocks Cluster (YAY!). Well, I hung on to that issue with the full intention of setting up a development/testing cluster when I had the chance. And that chance came just the other day.

Some of you probably don’t have a copy of the article, and I needed to do some things a bit different anyhow, so I am going to try and summarize here what I did to get my new dev cluster going.

Now what I needed is probably a little different that what most people will, so you will have to adjust things accordingly and I’ll try and mention the differences as I go along where I can. First off, I needed to run the cluster on RedHat proper and not CentOS, which is much easier to get going. I also am running my entire dev cluster virtually on an ESX box and most of you would be doing this with physical hardware.

To start things off I headed over to The Rocks CLuster website where I went to the download section and then to the page for Rocks 5.2 (Chimichanga) for Linux. At this point, those of you who do not need specifically RedHat should pick the appropriate version of the Jumbo DVD (either 32 or 64 bit). What I did was to grab the iso’s for the Kernel and Core Rolls. Those 2 cd images plus my dvd image for RHEL 5.4 are the equivalent to your one Jumbo DVD iso on the website that uses CentOS as the default Linux install.

Now at this point, you can follow the installation docs there (which are maybe *slightly* outdated(?), or just follow here as the install is pretty simple really. You will need a head node and one or more cluster nodes for your cluster. Your head node should have 2 interfaces and each cluster node 1 network interface. The idea here is that your head node will be the only node of your cluster that is directly accessible on your local area network and that head node will communicate on a separate private network with the cluster nodes. With 2 interfaces, plug your eth0 interface on all nodes, head and cluster into a separate switch and plug eth1 of your head node into your LAN. Turn on your head node and boot it up from the Jumbo DVD, or in the case of the RHEL people, from the Kernel cd.

The Rocks installer is really quite simple. Enter “build” at the welcome screen. Soon you will be at the configuration screen. There you will choose the “CD/DVD Based Rolls” selection where you can pick from your rolls and such. I chose everything except the Sun specific stuff (descriptions on which Rolls do what are in the download section). Since I was using RHEL instead of CentOS on the jumbo dvd, I had to push that “CD/DVD” button once per cd/dvd and select what I needed from each one.

Once the selections were made it asks you for information about the cluster. Only the FQDN and Cluster name are really necessary. After that you are given the chance to configure your public (lan) and private network settings, your root password, time zone and disk partitioning. My best advice here would be to go with default where possible although I did change my private network address settings and they worked perfectly. Letting the partitioner handle your disk partitioning is probably best too.

A quick note about disk space: If you are going to have a lot of disk space anywhere, it’s best on the head node as that space will be put in a partition that will be shared between compute nodes. Also, each node should have at least 30gb of hdd space to get the install done correctly. I tried with 16gb on one compute node and the install failed!

After all that (which really is not much at all), you just sit back and wait for your install to complete. After completion the install docs tell you to wait a few minutes for all the post install configs (behind the scenes I guess) to finish up before logging in.

Once you are at that point and logged into your head node, it is absolutely trivial to get a compute node running. First, from the command line on your head node, run “insert-ethers” and select “Compute”. Then, power on your compute node (do one at a time) and make sure it’s set to network boot (PXE). You will see the mac address and compute node name pop up on your insert-ethers screen and shortly thereafter your node will install itself from the head node, reboot and you’ll be rockin’ and rollin’!

Once your nodes are going, you can get to that shared drive space on /state/partition1. You can run commands on the hosts by doing “rocks run host uptime”, which would give you an uptime on all the hosts in the cluster. “rocks help” will help you out with more commands. You can ssh into any one of the nodes by simply doing “ssh compute-0-1″ or whichever node you want.

Now the only problem I have encountered so far is I had an issue with a compute node that didn’t want to install correctly (probably because I was impatient). I tried reinstalling it and it and somehow got a new nodename from insert-ethers. In order to delete my bad info in the node database that insert-ethers maintains I needed to do a “rocks remove host compute-0-1″ and then “rocks sync config” before I was able to make a new compute-0-1 node.

So now you and I have a functional cluster. What do you do with it? Well, you can do anything on there that requires the horsepower of multiple computers. Some things come to mind like graphics rendering and there are programs and instructions on the web on how to do those. I ran folding at home on mine. With a simple shell script I was able to setup and start folding at home on all my nodes. You could probably do most anything the same way. If any of you find something fantastic you like to run on your cluster, be sure to pass it along and let us know!

Nov 09

Tools of the trade

By linc Gear, work No Comments »


Just what kinds of tools do you need to do a systems administrator job? I Am talking about actual hand-type tools, not fancy laptops, big brains or large amounts of your favorite caffeinated beverage and pizza. Surprisingly, I use very few.

The first thing I picked up is a little toolkit. I don’t think you need to spend a lot of cash on it, in fact, mine was less than $6, but it needs a few important pieces in it. The most important by far, probably, is a halfway decent screwdriver with at least a small selection of bits. The kit I bought (from Microcenter btw) has a regular screwdriver with extension and bit set and also has a small selection of the small jewelers screwdrivers. Although I hardly ever use jeweler screwdrivers, if your glasses happen to fall apart or something, they sure are handy to have around! The kit also includes a pair of tweezers which I have never touched, and two more quite important tools, a pair of side cutters and a pair of needle nose pliers. You’d be surprised how handy both of those are.


The other must-have is a pocket knife. Really. I cannot tell you how many times I reach for my pocket knife a day. I use it for everything from opening boxes and cutting strapping/cable ties/old wires to perforating the film on my lunch before I pop it in the microwave (yes, I wash it off first). Some guys carry around a Leatherman or a Swiss Army Knife with all kinds of screwdrivers and other things attached, but my preference is single task tools. They just seem more rugged, easier to use and better suited for daily use. To that end I picked a decent little inexpensive pocket knife, a Winchester Parfive, which was well under $20.

The only other tool I can think of that might enjoy wide use for some Systems Administrators is a good Ratcheting Telemaster cable crimper. While I don’t really use one of those at my current Sysadmin job, I used to use it almost daily at my old job. Do yourself a favor and make sure you buy a good quality tool here with a comfortable handle. After you squeeze on it a few hundred times you’ll understand why :-)

Not the final authority on the subject, I am also interested to know what you might use yourself, and if you think I may have forgotten something. Just let me know by leaving a comment here or sending me an email in the usual manner.

Nov 05

FIRE!

By linc Customer Service, Home Life, work No Comments »

Even though it’s a day late, I thought I would share that my train caught on fire on the way into work on the 4th. Nobody was hurt (that I know of) but plenty of people were ticked off and it sure was stinky! For those that don’t already know, it just so happens that SEPTA is on strike, making the Regional Rail trains (the ones I ride) completely packed to overflowing and, of course, it’s tough to get to your destination when your train is out of commission and there are no buses running because of the strike. SEPTA seems to make money hand over fist while providing the poorest service you can imagine. It really gets under your skin after a while.

Anyway, the pics are here: Train Fire

Oct 26

Who needs work?

By linc Linux, work No Comments »

I remember several people at OLF recently telling me that they were hurting for / looking for some work. Well, I get hounded by headhunters quite often and would gladly pass stuff on to those people who are interested, but I need to know who you are :-) Send me an email at linc dot fessenden at G mail dot com and let me know.

Jun 04

Command Line Mail

By linc Email, Linux, Programming, work No Comments »

Here’s one for the book…:

I have a script that monitors a process and I want it to email my cellphone (to page me) if things don’t look just right. The problem is that just using “mail” or “mailx” in a script fails because my carrier divines whether or not my return address is real. Obviously a from field that looks like “root@localhost” is just not getting through.

What’s the solution? Enter “mutt”.

Mutt, it seems, will let you specify your from field in the ~/.muttrc file. Also, it works pretty much the same on the command line as mail or mailx. So, I set up mu ~/.muttrc like so:

set realname = "menotyou"
set from = "menotyou@myrealdomain.com"
set hostname = "myrealdomain.com"
set use_from = yes

And then, in the script I send mails like so:

echo "Wow I can send mail!" | /usr/bin/mutt -s "A present for you" myphoneaddr@provider.com

All in one line of course, but BINGO, all the sudden my cell phone springs to life at all hours of the night with information I don’t want to know :-)

Enjoy!

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