Donnie’s Blog

Anytime I am thinking about putting together a star party I have to do some research so that I can figure out some interesting things to look at. The sky is a big place after all, and there’s a lot of pretty lame things to look at. Also, “here’s a globular cluster that’s 4000 light-years away, with an estimated 3000 stars in it” is a lot more interesting than “ooo a cotton-ball blob!” when you are talking to people who aren’t so excited about astronomy. Or, if someone asks if you can see Neptune, it’s a lot nicer to say “Oh, it’s already set,” rather than “Hmm I don’t know where it is right now.”

I used to use the Sky and Telescope Interactive Sky Chart, but recently they changed it to require a user account, and even though the account is free, I don’t want to have one more account to remember. It’s just an extra hoop to jump through. So I looked around for some free star-chart software and I found Stellarium.

The neatest thing about Stellarium is that a lot of attention was given to visual appearance, and everything is rendered in true 3D with OpenGL. Sunrises and sunsets are rendered in a pretty realistic way, which is good if you want to get a feel for what is visible at a particular time. The band of the Milky Way is rendered for night displays, and the Small and Large Magellanic Clusters if you look from a location in the Southern Hemisphere. Constellations, including artwork, can be turned on as well. It was definitely an “ooh, ahh” moment, the first time I used it.

Anyway, if you are looking for a simple, free program for seeing what is in the sky, check it out. It’s quite nice.

Wow, am I glad that’s over.

In the ongoing saga of getting my new server set up, I was right at the point where I was going to switch my hard disks over to a RAID1 setup. I have two 500GB SATA disks, and probably about 200GB of data on the one of them. So I went through the process outlined in many places online:

1. Create a number of RAID1 partitions on the empty disk, to match up what you have on the full disk. These RAID1 partitions are set up with two devices, the empty hard disk and “missing”, which tells the RAID controller that you haven’t gotten around to adding the other device yet.
2. Copy all the data from the “normal” disk to the new RAID1 disk.
3. Get as much of your system ready to boot under RAID as possible. This includes editing /etc/fstab, making an /etc/mdadm.conf file, and setting up lilo to boot off the RAID partition.

…except that lilo wasn’t cooperating. You see, lilo doesn’t like to install onto a degraded RAID1 array, with the versions of kernel/lilo/whatever that I have.

#$@*. Doomed.

Oh well, let’s carry on!

Next came booting the rescue OS that comes with the Linux installer and finishing up the installation. The idea is that you finish setting up the RAID1 partitions under the rescue OS so they have a chance to fully sync up before you bring the system back up. This is the first place where I thought my 200GB of data was lost (well only the few dozen megabytes I generated since my last full backup, but that still had me freaking out), because I just couldn’t get the RAID1 partitions loading.

“Oh wait, maybe I need to load some module.” Ah yes. Today’s episode, brought to you by the Linux command “modprobe raid1“. Now I can see my precious data again…

Once the RAID1 partitions were all synched up, it was a small matter of getting all the boot-related stuff taken care of. This would have been simple, except that the instructions I was following had me do something like this:

  mount /dev/md1 /mnt/raid
  mount /dev/md0 /mnt/raid/boot
  chroot /mnt/raid /bin/bash
  source /etc/profile

This was to switch the system into a state like the final running system, so that I could complete the boot setup. Only problem is, /proc, /dev, and /sys are all empy, and I kinda need those if I’m going to do any sweet-talking with my hard disks.

That was the second “#$@*. Doomed.” moment. But, thankfully, I got it figured out pretty quickly (/proc was easy, /sys was kludgey, and /dev was gross), and got my boot stuff taken care of.

And now, it all seems to work! You are reading my blog again, after all.

I never want to deal with that again. If I have to, well, I’ll know how. But the reason I went through all this rigamarole in the first place was that I didn’t want to buy an extra hard disk, and in retrospect, I think I would have rather just had an extra HDD sitting around. It would be my emergency device/paperweight, or something.

I need smarter wiki software. Mainly because I tend to be a bit dense when it comes to using wikis. I am too used to the niceties of document editors that autosave your temporary work, and that will ask you if you want to discard unsaved edits when you close the application. But wikis don’t always offer that, and it has bitten me at least half a dozen times in the last six months. Either I hit the preview button and forget that I haven’t actually saved my changes yet, or I accidentally mash Shift-Backspace and navigate away from the edit page and the web browser doesn’t remember the form contents. Every time it’s completely demoralizing too, because I just wrote something amazingly profound, then stupidly obliterated it, and I know there is no easy way to get back to what I just lost.

I normally use PmWiki for my personal wikis because it is just so lightweight and easy to set up. There are just a few PHP files, not a lot of options, the format is simple to learn, and all the pages are stored on the filesystem so you don’t have to set up a database. Easy to backup and migrate, too! But this also means that it doesn’t have all the nifty client-side scripting that modern web applications provide, and so sometimes I shoot myself in the foot.

Oh well. PmWiki does in fact offer a plugin component that does the whole “Do you want to save your edits?” option; I think it’s probably high time I installed that.

Whining over.

Well, it looks like I have my mailserver and webserver back up and running, all on my new machine. It seems a lot zippier too, probably because of all the extra memory and processors.

I still have to switch my hard disks over to RAID1, which I am sure will be quite an adventure. I’m really not worried about it, except for the /boot partition. If /boot gives me trouble then I’m going to be outta luck for a while…

My new computer showed up yesterday, in a bunch of boxes. I assembled it yesterday and then started installing Linux on it today. We shall see how it goes.

One of the interesting challenges I have already faced with this machine is how to set up RAID with only one hard disk. You see, I have a second hard disk to put into the new computer, but it’s kinda busy serving up my stupid blog, and my e-mail, and all the rest. So I need to find a way to make this transition as smooth as possible.

This may not work, so don’t assume I’m an expert… but my current approach is to build a RAID1 array on the new computer, with only one hard disk in the array. Yes it would be dumb to leave it this way, but my idea is that when the new machine is all configured, I can just rsync all my data from the old machine to the new machine. Then I can turn off the old box and pull the HDD from it, drop it into the new machine, and add it into the RAID1 array.

And of course I will keep a backup just in case something goes horribly wrong…

When I was out acquiring my Mac mini, I happened to be in the neighborhood of my old elementary and high school. And what do I see?

This is where the elementary school portion of my school was. Along the right side were the Kindergarten through 3rd Grade classrooms. The big tree was in the middle of the area where we would have recess.

I think the line of trees in the middle ground is where the parking lot was. Behind that was the high school complex.

This is where I worked during the last couple years of high school. There was an office equipment maintenance shop there, and I would do all kinds of work there, usually involving cables and tight dusty crawlspaces. Looking back, I can see why the guys had me do that stuff.

Anyway, I am so *sniff* heartbroken *sniff* to see my school razed to the ground.

Yeah, right.

Man, I hate buying new computers. I would actually prefer cleaning up indigestion-related dog accidents in the kitchen than buy a new computer. Thankfully I only have to do this every 2-3 years.

I didn’t really need to upgrade my computer - it’s actually pretty great for my needs - but my mom really could use a new computer, and she usually gets my hand-me-downs. It works for iPods, cameras, computers… Her computer is a wretched old thing, and it was getting increasingly painful to use, so I went ahead and bit the bullet and ordered a new computer.

Don’t ask me why, but I decided to get the Intel Core 2 Quad processor in this computer. I love processors, the more the better. It’s always suited my obsession with high-performance server programming and concurrent programming. I also decided to get 4GB of RAM, so I am officially entering into the 64-bit operating system world. Finally, I decided to try out one of the graphics cards with the nvidia 8800 GTS chipset on it, so I will get to see how far the graphics technology has progressed since my last computer. I only got 320 MB of RAM on the graphics card though, since I like graphics programming, not gaming, so I don’t really need tons of texture memory.

My mom will get a pretty fast computer out of this too, so hopefully that will make her life much, much easier.

One of the software projects I have been working on over the summer required the software to be built for MacOS X, but not just any old version - it had to be built for MacOS X 10.3.9, and it had to run on the PowerPC.

This was an interesting challenge. Especially since I didn’t have a Mac!

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