debian

When Linux won’t boot off DVD or USB

Dave Farquhar Linux , , ,

I went to install Linux (Debian) on an old Asus socket 775 motherboard (a P5LD2) and had a litany of problems getting my installation media to boot. Here’s how I finally got it installed.

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I fought the white screen, and I won!

Dave Farquhar Linux ,

WordPress occasionally suffers from the dreaded “white screen of death,” where you visit an admin page and, instead of being able to do what you want to do, you get a blank white screen. Meanwhile, the blog continues to function. If you have scheduled posts, they keep going. But with no admin access, the blog essentially becomes a ghost ship.

Several of the causes are pretty well documented, so I’ll talk about mine instead of rehashing old advice you can easily find elsewhere. Read more

Bash is worse than heartbleed! Oh noes!

Dave Farquhar security , , , , , , , , , ,

A really bad remote code execution bug surfaced yesterday, in Bash–the GNU replacement for the Unix shell. If you have a webserver running, or possibly just SSH, it can be used to execute arbitrary code. It affects anything Unixy–Linux, BSD, Mac OS X, and likely many proprietary Unix flavors, since many of them have adopted the GNU toolchain.

This could be really bad. Some people are calling it potentially worse than Heartbleed. Maybe. I’m thinking it’s more along the lines of MS08-067. But there’s an important lesson we must learn from this. Read more

When Linux is easier than Windows

Dave Farquhar Software , , , , , ,

A few months ago I bought a Gigabyte GA-Z77M-D3H to learn computer forensics on, because at the time I thought that was the direction my career was going. I dropped it into a neglected Compaq case and installed Linux on it, since most of the free forensics tools run on Linux. The current version of Debian loaded effortlessly and ran nicely, as you would expect on a dual-core CPU with 16 gigs of RAM.

Then my career went another direction. Today I analyze Windows threats and vulnerabilities for a living. That’s a better match for my experience and the pay is the same, so I’m perfectly fine with that. But my mind turned to that hotrod computer in the basement. I suppose I could still use it to learn forensics, but I probably won’t, so why not see how Windows runs on it and bring it upstairs? Read more

Not your father’s Celeron

Dave Farquhar Hardware, Linux , , , , , , , , , ,

I picked up a Celeron G1610 CPU last week and I’m using it to build a Linux box. Yeah, it’s a Celeron. But it performs like a 2011-vintage Core i3 or a 2010-vintage Core i5, consumes less power than either, and costs less than $50. It’s hard to go wrong with that. Read more

How to build bootable Debian installation USB media from Windows

Dave Farquhar Linux, Windows , , , , ,
How to build bootable Debian installation USB media from Windows

Debian 7.0 (Wheezy) came out this weekend, and I want to mess with it. Here’s how I wrote the installation media to a USB thumb drive for it using a Windows box. Because sometimes that’s all you have available to work with. If you prefer another Linux distribution, like Ubuntu or CentOS or Fedora, the same trick will work for them too.

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Here’s a nice Linux tool: checkrestart

Dave Farquhar security , , , , ,

Tom Gatermann told me about a nice tool for Debian (and presumably Ubuntu) called checkrestart. Sometimes, even though you did an apt-get update and apt-get upgrade to bring your system up to date, you can still be running the out-of-date version of something. That’s the problem checkrestart helps you solve.

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Another easy Apache tweak

Dave Farquhar Apache , , ,

I ran my site through Google Page Speed on Tuesday, and scored a surprising 88 out of 100–higher than I expected. Getting above 90 is going to take some optimizations on files that WordPress updates may change, so I’m hesitant to do that, but one thing it told me to do was to cache more aggressively. That’s pretty easy, as it turns out, and I could definitely feel a difference afterward.

Here’s the trick. Read more

Use Apachebench to test your webserver optimizations

Dave Farquhar Apache , , , , ,

If your web server is slow and you want to fix it, it’s nice to be able to quantify what you got. Enter Apachebench, which is part of Apache and probably already on your server. Read more

How to start over with MySQL in Debian

Dave Farquhar Linux , , , , , ,

I got my new 64-bit web server up and running today. Now the main task that remains is to get my data moved over to it. I talked myself into going with an Apache setup, since one program I want to run (Webtrees) is designed for Apache and its search engine optimization seems to work better under Apache than Nginx. It’s fast anyway; displaying the 17-person family of Andrew Davis McQueen of Leesville, Mo., briefly consumes 2% of the available CPU time in Webtrees with the APC PHP cache installed and enabled. And that should get better, seeing as newer, faster, better versions of both Apache and PHP were released in the last month.

As I built my new 64-bit web server, I messed up MySQL a couple of times. When you break MySQL beyond repair, here’s how to start over with a fresh MySQL install and a fresh /var/lib/mysql without doing a Windows-like reformat and reinstall of the entire operating system:
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