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Month: August 2012

Scientific Linux, ThinkPad, and WiFi

It's no secret that Linux doesn't have the same level of hardware support as Windows. In some cases, Linux systems can be run where Windows wouldn't dream of being installed. On the other hand, Windows has great support for many recent devices that Linux doesn't support (either in full or in part). The wireless device on my ThinkPad is:

[Doug@FLASHMAN-SL ~]$ lspci -nn | grep -i real
03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter [10ec:8176] (rev 01)

The appropriate driver for this (found from ELRepo.org) is kmod-r8192ce. I followed the instructions on the website to add ELRepo as a repository and then had it install kmod-r8192ce. After a restart, things seem to be looking good:

[Doug@FLASHMAN-SL ~]$ lsmod | grep 8192
rtl8192ce 51681 0
rtl8192c_common 45957 1 rtl8192ce
rtlwifi 71279 1 rtl8192ce
mac80211 423615 3 rtl8192ce,rtl8192c_common,rtlwifi

While this got the basic wireless working, things were not perfect. After connecting to any network, either secured or unsecured, I would be able to surf the web for a few minutes.... followed by nothing. The connection would just die after a few minutes (or seconds). When the connection would drop, my computer would still think I was connected, and disabling and re-enabling the network or disconnecting and reconnecting would not solve the problem. I had read that IPv6 sometimes can interfere with the network connectivity if it isn't being used (I am still on IPv4), so I appended ipv6.disable=1 to the kernel in my /etc/grub.conf file. Still not working great, but marginally better. Eventually, I began using a kernel from the 3.5 branch as opposed to the Scientific Linux 2.6 kernel. Together with the ipv6.disable=1, this seems to result in a solid connection.

Future goals

  • Whenever I update my kernel (and thus grub.conf file), a new kernel becomes the default... which is sometimes a 2.6 branch kernel. When I don't interfere with the start up, it can be frustrating when my internet dies again. I would like to have grub not change the kernel that I am running from 3.5 to 2.6. [Edit 2: For the time being, I am manually updating grub.conf after each kernel update.]
  • I need to check if ipv6.disable really offers benefits when used with the kernel version 3.5.
  • I'd like to figure out a way to display code snippets on wordpress. [Edit: It seems that this functionality is possible through wordpress plugins, but as my blog is currently hosted on wordpress.com it is not possible to use any. A medium-term goal of mine is to create a new website that includes this blog as a feature, so when that happens I'll re-edit this post to add in code snippets.] [Edit 3: I installed the SyntaxHighlighter Evolved plugin after moving to WordPress.org. Apparently, though, this feature is available on WordPress.com, though I didn't figure that out at the time. Of course, one could just use <pre> tags, which I had forgotten about.]
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My ThinkPad specs

One of the primary focuses of this blog is going to be the technology (software/hardware/devices/etc.) that I use to be productive. The first few posts I assume will relate to software on my laptop (and fixing issues). Now, because laptop configurations vary considerably, I'm going to post everything I can about my computer so that if others experience similar issues there is a greater likelihood of finding the solution. I have more than one computer, so posts that are primarily concerned with this computer will be tagged with "ThinkPad T420i".

Lenovo ThinkPad T420i Hardware (Model 4177-CTO)

  • Processor: Intel Core i5-2430M processor (dual-core, 2.40GHz, 3MB Cache)
  • Memory: 8GB PC3-10600 1333MHz DDR3, non-parity, dual-channel capable (two 204-pin SO-DIMM sockets) (It may be possible to upgrade this to 16GB based on some things I've read (sources later), but it is currently listed as 8GB as the maximum memory.)
  • Chipset: Mobile Intel QM67 Express Chipset
  • Screen: 14" screen supporting 1600x900 resolution
  • Graphics: Intel HD Graphics 3000 (integrated)
  • Wireless: 1x1 11b/g/n, Wireless LAN PCI Express Half Mini Card, Intel Centrino Wireless-N 1000

Lenovo ThinkPad T420i Software

  • Microsoft Windows 7 Professional (64-bit)
  • Scientific Linux 6.2 (64-bit) (SL is a Red Hat Enterprise Linux clone)

I'm currently trying to switch to Scientific Linux as my primary operating system, so there will certainly be some posts about overcoming issues I've experienced with this (slow) transition. I'll keep this list updated with changes or additional information (or corrections) as I find them.

Below are a few documents I've found on the Lenovo support website which list detailed information about this computer (and related ones). I've posted them here because locating them wasn't obvious on the Lenovo website and, as products age and are no longer supported, the supporting documentation has a habit of disappearing.

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Orientation 2

The second orientation was much the same as the first: the emphasis was on a doctoral degree as more than the accumulation of credit hours (networking, work outside of the classroom, etc.). Nothing new, but it does bear repeating. There was a little bit more information on the rules and regulations of the Graduate School and the department, but from my time at UF these are old hat.

There were many specializations represented by the students at the orientation, and the department seems to really try to make a cohesive group of them all.

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Orientation 1

This morning was the first of two orientations in my new department. This one was a small meet and greet with the graduate coordinator Dr. Terzian, but it was really emphasized that the department wants the on-campus Ph.D. students to be a community of scholars, a pleasant change from my old department. My old department was also in favor of the community of scholars feel, but did little to cultivate it. It was also emphasized that after the breadth of the first few years of graduate school, we need to come up with a question that is "original, important, and answerable", resulting in a narrowing of focus marking the beginning of the dissertation phase. Again, this is not a new realization or unexpected, but the department's forthrightness and attention they (hopefully continue to) give students is welcome.

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Begin first blog entry #17.

I'm not even sure that was hyperbole. I've tried and failed at starting blogs before, but this time something has changed: I actually have something about which I wish to blog.

Tomorrow is orientation for the School of Teaching and Learning in the College of Education at UF. My new home. In less than a week I formally begin the pursuit of a Ph.D., and I would like to document it. The first two years of grad school were extremely challenging, and I partially regret having no documentation of the journey. Moreover, I've been noticing discernible changes in my attitude toward life and key aspects thereof. For lack of a better term, I think I'm really growing up in a substantive way. Eventually, I would like to have this blog transform into more of a statistics education blog, but that's down the road.

To recap, this blog will include:

  • Graduate school things (anecdotes, key events, milestones, etc.)
  • My professional progress
  • Things which I find relevant to my academic life (software workarounds, fixes, etc. - more for my future reference than anything)
  • Experiences with growing up (but in a fact driven way)
  • Statistics education postings (examples, data, etc.)

This blog will NOT include:

  • Pictures of my food
  • Where I am 24/7
  • Political/religious ideology/rants
  • Things of a solely personal nature
  • What pleasure books I'm reading

If I stick with this blog (I will! I will!) the creation of another blog for the aforementioned exclusions might be in order.

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