Squid Tip

Saturday, 25 July 2009 22:04

So I've been updating my Joomla! version to the latest version and adding some new components/plugin's to this website - I can into a problem where I couldn't get TinyMCE to run due to some weird errors.

Turns out, it was a cache issue, but not at the browser level. I'm a geek, everyone knows that - and as a geek, I like my websites to be fast, so I have a 75Gig proxy server - sigh, alas, the proxy server was caching the TinyMCE js files - I had todo a little digging to find out how to expire that.

I didn't want to expire the whole cache - that would just be dumb - but found lots of websites that describes howto do that.
I also couldn't find a way to expire it via the cachemgr program - weird, I know.. but alas, you can't do it from there.

I did finally find the way todo it, and I figured I'd better at least mention it here for you.

To force cache clearing of a specific item you can use the squidclient command line tool as shown below.

squidclient -m PURGE 'URL'

Simple no?
Enjoy

Wii MythTV Update

Monday, 20 July 2009 21:45

I went to pick up a USB->Ethernet net adapter for $9, but I wasn't sure it would work - Unfortunately, they didn't have any - So i'm delayed at this point.

My end goal is:

Have a LiveCD type boot from the SD Card so that No partitioning is required - problem with this is that the configuration would need to be saved - at this point, it appears as tho, the only config I would need to keep is the database connection details stored in /etc/mythtv/mysql.txt and /etc/mythtv/config.xml (which may not be correct).

So - Using the Homebrew Channel, you'll be able to load up the .elf file, which boots a LiveCD, the LiveCD will mount and check for a config on the SD Card which will then create the required config files. All this, while looking pretty.

Another thing I need todo is strip out all the things we won't be using from the Linux Distro I'm basing this off of - thus making it as small as possible.

A quick reminder, that you will need a USB Network adapter, because, at this point the linux kernel does not support the internal wifi adapter. Secondly, it should be noted that the Wii will only run in USB 1.1 mode - Thus, limitting to 12MB/s.

Mythtv... Wiiiiiiiii

Saturday, 18 July 2009 23:34

Ok - So, I've been waiting around for someone else to build a working mythtv front end for the wii, using home brew.

To say the least, I have up waiting and did it myself ;)

I took a basic Linux stack for the wii, found OOC deb packages and manually installed them into my SD card, tracked down and install all the required libs and well - to say the least - WIIIIIIII I have a mythtv front end, almost.

Unfortunatly, all the USB ethernet addaptors I have don't seem to work on the wii with linux - so I'll need to go pick up one of those to confirm that this is working. Once I get to confirm it's working, I'll preatty and clean it up build some tgz's of it and provide some details on how to install it.

Keep checking back here to see my progress!

Sorry for the lack of updates

Sunday, 22 March 2009 19:33

And thanks for all the fish? No, wait.. wrong book ;)

Xen and the Art of QCows

Wednesday, 07 January 2009 21:51

I've been working on a special project.. one that requires the building of multiple virtual machines on the fly. My VM of choice (as seen in previous entries) is Xen.

Part of my requirements is the ability to have a base image of a root drive, then have each of the dynamic VMs have their own dynamic image based on the original. One, if they wanted to, and had the space - could just copy the drive image multiple times. And this would work.

Fortunately, there is a better way. Copy-on-write disks are disks that write changes from a base image to a separate file. Thus, reducing the overall usage. This is what I want.

Xen wiki has multiple solutions to doing this, however, I wanted something simple, and supported at the xen level. This left me with qcow files.

In order to save some people some time. I wanted to describe how I went about getting the images to work -- pain for me, means less pain for you in the long run.

To make a long story short:

1. Created a image with dd (see previous posts)
2. Made my changes to the image
3. used "qemu-img convert -O qcow2 (base-img) (qcow-img)" to convert the image to a base qcow format
4. built the actual qcow files with "create-qcow (image-size) (container-qcow) (qcow-img)"

Some notes:

• When building your base image with dd - it CAN NOT be a spare file (meaning using the seek) it must be a full img
• img2qcow does not work! (or at least it didn't for me)

Some errors you might see

• Failed to write new L1 table  (Usually after: Converting image to big endian L1 table)
  
  • Your using qcow files, not qcow2 - probably because you used img2qcow or -O qcow with qemu-img
• QCOW Open failed
  • You may have used qcow-create, but referenced a raw image - not a qcow image.
• XENBUS: Waiting for devices to initialise
  • One of your devices didn't init in dom0 - look at /var/log/syslog to find the error in your ways