gwax's rumblings

I recently considered the naming of abyss and decided that the word oubliette made a better name. Oubliette is a much more appropriate description in understanding the theme and purpose of the machine as a replacement for thevoid.

The name change happened a while ago but I’m bringing it up now because oubliette is on my mind. Having just purchased six Western Digital 1.5TB drives and another SATA controller, it is finally time to obsolete the last remnants of thevoid. This actually stirs some amount of sentimentality in me but, even though the hardware and operating system are no longer that of thevoid, oubliette will carry the purpose and data forward. It is almost as though oubliette is my ghola thevoid.

For those with technical interest, the drives will be arranged in an mdadm RAID6 array with luks dm-crypt. This should provide me with 6TB, secure storage, and two drives worth of failsafe.

I have finally decided, after 7 years of faithful service, that thevoid is due for decommissioning as my primary desktop. I love thevoid, she’s a great machine but at a 1.8GHz single core, 1GB of RAM, no USB2, no SATA, no PCI-E, no PCI-X and fans that are starting to make squealing/grinding noises, she’s fallen a little far behind the technology curve. My general view on desktops is, and for a long time has been, to get a core setup with the most expandability possible and then incrementally upgrade for as long as possible; following that principle, I am replacing thevoid with abyss.

Abyss (current specs)

• Lian-Li PC-A77B case
• Tyan Tempest i5400PW (S5397) motherboard
• 2x Intel Xeon E5420 2.5GHz quad core CPUs
• 4x Kingston 1GB 667MHz FB-DIMM RAM
• 2x Western Digital 500GB SATA HD
• Lite-On SATA 20X DVD±R

Abyss (planned upgrades) (as funds are available)

• 4x Kingston 1GB 667MHz FB-DIMM RAM
• Some medium-to-high-end nVIDIA video card
• some medium-end multi-channel sound card
• Highpoint RocketRAID2240 16-channel SATA controller
• 3x Icy Dock 5-bay SATA backplane
• 15x 750GB HD

The hardware in abyss has been specifically chosen to have support for Intel VT-x and VT-d virtualization technology so as to allow for as versatile a machine as possible. Abyss is already running Xen with Gentoo Linux as the primary, dom0, operating system and Windows XP as a secondary, domU, operating system. My hope, after adding a video and sound card, is to install another Gentoo Linux and Windows XP operating system, as well as a Windows Vista operating system. Ultimately, the current Gentoo and Windows operating systems will always run in the background, primarily acting as headless servers for underlying services, and for day to day usage I will be able to switch between Gentoo, XP and Vista domains based on my needs. In essence, I will have a dual-booting system of virtual hosts with direct access to my video and audio hardware.

Hopefully abyss, with some incremental upgrades, will serve my computation needs for the next five to ten years.

There is a right way and there are wrong ways to add drives to a RAID5 array with mdadm. Annoyingly, I chose one of the wrong ways last week when I went to increase the hard drive space in thevoid. Thankfully, my mistake has proven more bothersome and time consuming than harmful.

Starting out last week, thevoid had 4x 500GB drives in an mdadm RAID5 configuration: /dev/hde1, /dev/hdg1, /dev/sda1, /dev/sdb1. This had me sitting on 1.5TB of space with one drive worth of failability, which was proving insufficient. In order to resolve my space issues, I ordered 3x 500GB drives and proceeded to install them when the arrived: /dev/hdb, /dev/hdc, /dev/hdd.

In my haste to have more space, I proceeded to add them to the array and grow it:

mdadm --manage /dev/md1 --add /dev/hdb
mdadm --manage /dev/md1 --add /dev/hdc
mdadm --manage /dev/md1 --add /dev/hdd
mdadm --grow /dev/md1 --raid-devices=7

This process then got to work and took about 3-4 days to complete. I assume the time was on account of most of the drives being IDE drives, many sharing channels and there being an awful lot of space. Once the growing process was complete, I merely needed to resize the ext3 partition on the array:

resize2fs /dev/md1

This then took an hour or so and I was sitting on 3TB of total space. The only part of the process during which my drive was inaccessible was when I had to turn off the computer to physically install my IDE drives.

Everything is perfect now, right? Wrong. Guess who forgot that you should partition drives before using them? That’s right, me. I really wanted to put a linux raid autodetect partition on each of the drives before adding them to the array. Not that it really does much harm to add the drives straight to the array but it’s poor form and it might pose problems that I am not aware of in the future so, clearly, it’s a thing that should be fixed. Thankfully, being RAID5, my array is able to lose drives and still be fine, thus allowing the solution of failing, removing, partitioning and adding each of the new drives back into the array:

mdadm --manage /dev/md1 --fail /dev/hdb
mdadm --manage /dev/md1 --remove /dev/hdb

partion /dev/hdb and then:

mdadm --manage /dev/md1 --add /dev/hdb1

now wait until the array has rebuilt itself:

cat /proc/mdstat

and repeat for the other drives. Overall, it’s not hard but it’s annoying and it does take about 1/2 to 2/3 of a day per drive to fix. Thankfully, though, now the endeavor is done and my array works correctly with no lost data and minimal down time. Hooray for software RAID and having 3TB in a single place.

Oh, and you don’t want to forget to update /etc/mdadm.conf after every step of the process of you could have some potential problems.

I was talking with my brother, who is not a computer geek, and discussing variations on Linux when he came up with an amazing analogy that was so brilliant I had to share it with the rest of you. He said, “I guess it would be more like a blank piece of paper versus a color by numbers thing”. It’s exactly spot on, Ubuntu is the paint-by-numbers of Linux; it’s really easy to do the stuff it’s aimed at doing but going outside the lines doesn’t look as good as if you’d used a more general option. Of course, while you Ubuntu users are all kindergarteners, I’m busy ricing out my machines with Gentoo; I don’t actually know which is a worse thing to be analogized to.

I’ve always been rather fond of trying new things that twist the way I think about and interact with things and computers are no exception. Ever since I used The Typing of the Dead to learn how to touch type, I have taken an interest in keyboard layouts and designs and the more time I spend typing in my life, the more I come to understand the effects of typing comfort compounded over time. Prior to 2001, I was a dedicated 2-4 finger typist, capable of achieving over 30-40wpm using what amounted to “hunt and peck” without the hunting; it was essentially a successive offsetting solution using memorized relative positions to guide my hands. Then, in 2001, I built my beloved thevoid and got a Microsoft Natural Keyboard Pro because it looked cool, had a USB hub and some neat programmable function buttons. The Natural keyboard has the fairly standard split keyboard layout, which completely broke my relative position scheme–the gap in the middle prevented cross-overs, which were integral to the scheme. At that point I slowly began learning how to touch type but later in the year, I discovered The Typing of the Dead and that changed everything; in addition to making speed typing a game, it also included a very useful typing tutor.

Having learned proper touch typing, I had divorced myself from cross-overs and was able to enjoy the comfort provided by a split keyboard. Additionally, at this time, I was living in a dormitory with my good friend, Riad, who swears by Kinesis ergonomic keyboards, which I must agree are really comfortable. The Kinesis keyboard is probably the most comfortable and ergonomic keyboard solution that I had encountered prior to the jerry-rigged solution that I’ve just devised (see below). The Kinesis keyboards, however, have the huge disadvantage of being really expensive.

From there, my keyboard experiments languished for a number of years until one day, when I was bored, I put lettered stickers on thevoid’s keyboard keys and switched the layout to a Dvorak layout. Learning Dvorak was not entirely painless and I eventually gave it up because the positions of the ‘[/{' and ']/}’ keys made C/C++ programming inconvenient–this later turned out to be because I didn’t full learn to touch-type Dvorak. I have switched to Dvorak and back probably half a dozen times since, getting better each time; sometimes using Dvorak and QWERTY concurrently on different machines. At this point, I can switch between Dvorak and QWERTY with ease and I can say, without reservation, that Dvorak is much easier, faster and more comfortable than QWERTY. At present, I am using QWERTY because some of my keyboards are not suited to Dvorak layouts and it makes my new configuration more practical.

Recently, I’ve started to notice more so than before, how very uncomfortable it is to touch-type on an unsplit keyboard; the arm and wrist contortion is terrible. I was thinking that I might do well to ask the IT department at work if I could get a split keyboard but I’m much more the type to improvise an elaborate solution than walk 100 feet and ask someone for something. I asked myself what the ideal layout would be and decided that a split keyboard solves the wrist contortion but it still requires the arms to be uncomfortably tight in to the body. The solution: two keyboards, one 45° left, one 45° right, mouse in the center; each hand uses half a keyboard and it turns out to be really comfortable. If I want to adjust how one hand rests, I only need to adjust that one keyboard. Sure it takes a lot of desk space but I have that in spades right now and it really complements my multi-monitor setup. This is my akimbo solution and I really like it; if you know how to touch-type, have the desk space and a spare keyboard, I highly recommend giving it a try. Having just checked with a small online test, I am averaging about 60wpm and 96% accuracy with my keyboards akimbo layout.

Also, just so we’re clear, I do know that akimbo is etymologically incorrect but it is a linguistic mutation that I approve of.

I am–and have for quite a while been–a huge proponent of GNU Screen for the many-fold improvements that it provides to terminal and SSH sessions. One of the things about screen is that it runs in two processes, one is a headless process that redirects terminal output of applications to it (server process) and the other is a process which connects to the server process allowing interaction with and the viewing of output from applications in the server process (client process). The advantage to this two process approach is that you can run screen from an SSH connection, disconnect the client process, leave and then later reconnect a new client process to the same server process you started earlier, thus allowing session persistence. It’s a wonderful application with many other features that make my life easier.

In addition to being fantastically useful, screen appears to have been written by someone with a sense of humor as it seems to contain rather a few Easter Eggs. One particular Easter Egg that I recently came across is that if the server process dies while the client process is still connected, you meet the error message:

Suddenly the Dungeon collapses!! – You die…

It’s a cryptic and ominous error message that might put you off a little if you don’t know what’s going on. A quick googling will show that some have accidentally misinterpreted the meaning; thankfully I could guess what it was and check google for confirmation.