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SciPy 2008 - Software & Tools STATUS: Day 1 - Thursday: Concluded. Day 2 - Friday: In progress. Astronomy: Enzo [ home ] yt (related to Enzo) [ home | scipy ] Books: Computational Modeling and Complexity Science...


An example of checking out a git tag using Qt 4.6.0... Clone the Qt repository: $ git clone git://gitorious.org/qt/qt.git Show available tags: $ git tag -l output: v4.5.1 v4.5.2 v4.5.3 v4.6.0 v4.6.0-beta1 v4.6.0-rc1 v4.6.0-tp1 Checkout v4.6.0: $...


Building 64-bit/32-bit Debug&Release Universal Build... See my directions on checking out Qt 4.6.0 from the git repository if you do not already have the source code. Launch a Terminal and cd to the source directory. Run configure w/ 64-bit & 32-bit...


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NX> 147 Server capacity: reached for user: – FIX

Posted on : 31-05-2012 | By : Brandon W. King | In : Computers/IT, Error Fixes, Linux, Mac OS X, Systems Administration



If you get this wonderful NX error message and are looking to fix things, I believe I have the solution:

NX> 203 NXSSH running with pid: 19955

NX> 285 Enabling check on switch command
NX> 285 Enabling skip of SSH config files
NX> 285 Setting the preferred NX options
NX> 200 Connected to address: <ip address> on port: 22
NX> 202 Authenticating user: nx
NX> 208 Using auth method: publickey
HELLO NXSERVER – Version 3.2.0-73 OS (GPL, using backend: not detected)
NX> 105 hello NXCLIENT – Version 3.2.0
NX> 134 Accepted protocol: 3.2.0
NX> 105 login
NX> 101 User: <user>
NX> 102 Password:
NX> 103 Welcome to: <host> user: <user>
NX> 105 listsession –user=”<user>” –status=”suspended,running” –geometry=”2560x1024x24+render” –type=”unix-kde”
NX> 127 Sessions list of user ‘<user>’ for reconnect:
Display Type             Session ID                       Options  Depth Screen         Status      Session Name

——- —————- ——————————– ——– —– ————– ———– ——————————

NX> 147 Server capacity: reached for user: <user>
NX> 105 startsession  –link=”adsl” –backingstore=”1″ –encryption=”1″ –cache=”128M” –images=”512M” –shmem=”1″ –shpix=”1″ –strict=”0″ –composite=”1″ –media=”0″ –session=”<session>” –type=”unix-kde” –geometry=”2560×976″ –client=”linux” –keyboard=”pc105/us” –screeninfo=”2560x976x24+render”

NX> 599 Server capacity: reached for user: <user>
NX> 500 ERROR: Last operation failed.
NX> 105 NX> 280 Exiting on signal: 15


  1. ssh onto the system
  2. use top or ps to find nxagent (and maybe nx*) for your user
  3. kill those processes
  4. log in with nx

Dell Vostro 400 – Ubuntu/Kubuntu Linux

Posted on : 22-02-2008 | By : Brandon W. King | In : Computers/IT, Error Fixes, Linux, Systems Administration

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I was able to get a Dell Vostro 400 to work with Kubuntu 8.4 Alpha 4 LiveCD. I used the installer and it resized the Windows XP partition just fine… What I did to get this to work is written below:

Okay, SATA cdroms and Linux don’t seem to be mixing very well… at least not with Ubuntu/Kubuntu 7.10. If you pop in one of the live cds, it will likely give you an IO Error when you select any item on the live cd boot menu.

As it turns out, that problem is fixed in Ubuntu/Kubuntu 8.4… but it’s not out yet being Feb 22nd (Release date scheduled for April). But, the live cd works with 8.4 Alpha 4 (looks like Alpha 5 came out today), which can be found here: https://wiki.kubuntu.org/HardyHeron/.

When I booted the live cd, the screen went blank… The next time I booted off the live cd, I choose F6, and removed “quiet splash” from the kernel arguments.

At some point you might run into an error like:

Feb 22 21:55:19 localhost ata2: failed to recover some devices, retrying in 5 secs

If this happens add the kernel argument irqpoll and it should bypass/fix the problem (not sure which; it just worked).

To add the irqpoll option in the live cd:

  1. Select F6
  2. Remove “quite splash”
  3. Add “irqpoll”

To add the irqpoll option to grub (once installed):

  1. Replace # defoptions=quiet splash with # defoptions=irqpoll

I am in a bit of a hurry during this post today, so if you have any questions or would like me to expand on something, just post a comment.

Evil Spammers

Posted on : 28-08-2007 | By : Brandon W. King | In : Computers/IT, Linux, Systems Administration

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Those evil spammers figured out I had misconfigured my postfix smtp configuration before I did and they started using my server to forward spam! The configuration has now been fixed, but I wanted to point out a useful link on setting up postfix smtp authentication using sasl:

How to force SMTP authentication in postfix by Kevin Bailey

Dell Inspiron 9400 Ubuntu 7.04 (Fiesty) X won’t start & bcm43xx_microcode5.fw missing!

Posted on : 13-06-2007 | By : Brandon W. King | In : Computers/IT, Linux, Systems Administration

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If you have Dell Inspiron 9400 and are having trouble with Ubuntu or Kubuntu 7.04 (Fiesty) and you are getting the following errors or behavior, then you have come to the right place (Note: End of post has details of the hardware in this Dell Inspiron 9400):

bcm43xx: Error: Microcode “bcm43xx_microcode5.fw” not available or load failed


Failed to start the X server:
Fatal server error: no screens found

Failed to start the X server problem:
Even if you manage to get the Ubuntu installed without getting X to start from the Ubuntu live cd, you will still need to fix the problem once it is installed. Here is how to you can get the Ubuntu live cd to work (assuming you have the ATI X1400 graphics card):

  1. Boot from the Ubuntu 7.04 live CD and wait for the message saying X could not start. Get through the error messages until it drops you into a bash shell.
  2. Use your favorite text editor (or nano if you can’t find yours) to uncomment the universe line from /etc/apt/sources.list: sudo nano /etc/apt/sources.list
  3. sudo apt-get update
  4. sudo apt-get install xorg-driver-fglrx #Install the ati 3d accelerated driver
  5. sudo aticonfig –initial #creates a new xorg.conf setup for ati cards
  6. sudo modprobe fglrx #loads the ati fglrx driver
  7. sudo /etc/init.d/gdm restart #(for ubuntu) or sudo /etc/init.d/kdm restart #(for kubuntu)
  8. X should now start. Once you install you can repeat the same steps to get it working for the installed copy.

bcm43xx: Error: Microcode “bcm43xx_microcode5.fw” not available or load failed problem:
This is the error with the wireless card driver which requires firmware that is not installed by default. There is an easy way to install the firmware. Just install the bcm43xx-fwcutter package. It will ask you if you want it to automatically download install the firmware you need. Just say yes and it will do all the work.

  1. Follow step 2 from the previous section.
  2. sudo apt-get install bcm43xx-fwcutter #Make sure to tell it to download and install the firmware.

This Dell Inspiron 9400 Specs:

  • Intel Core 2 Duo T7200
  • 17 in UltraSharp TrueLife Wide-screen WUXGA (1920×1200 max resolution)
  • 2GB DRR2 533MHz RAM
  • 256MB Ati Mobility Radeon X1400 graphics card
  • 120 GB 5400RPM SATA HD
  • Integrated 10/100 Network Card (Broadcom BCM4401-B0 100Base-TX (from lspci))
  • Dell Wireless 1390 802.11g Mini-card (Broadcom Dell Wireless 1390 WLAN (from lspci))
  • 8X DVD+/-RW Drive
  • Integrated High Def. Audio (Intel 82801G High Def. Audio Controller (from lspci); works great by the way.

** (beryl-manager:6606): CRITICAL **: can’t execute beryl-xgl: Success

Posted on : 25-05-2007 | By : Brandon W. King | In : Computers/IT, Error Fixes, Linux, Systems Administration



If you get the following error when trying to launch beryl-manager with KDE on Kbuntu 7.04 (Feisty) (likely with an ATI card from what I am reading):

** (beryl-manager:6606): CRITICAL **: can’t execute beryl-xgl: Success

The problem most likely has to do with this bug:


Which basically states that beryl-xgl was removed from beryl-core package due to how it is built.

xen + routed network (shorewall) + qemu

Posted on : 09-02-2007 | By : Brandon W. King | In : Computers/IT, Error Fixes, Linux, Systems Administration, Virtual Machines

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After setting up xen and configuring buildbot on a xen guest domain, I decided it was time to bite the bullet and setup shorewall to hide the xen guest domains behind a private network.

By the way, there are some nice guides on setting up shorewall with xen:

In the process I had to reconfigure Xen to use routed networking rather then bridged:

Changed (/etc/xen/xend-config.sxp) from:

(network-script network-bridge)
(vif-script vif-bridge)


(network-script network-route)
(vif-script vif-route)

After setting up shorewall properly and being able to log into two different Debian etch guest domains, I noticed that my previously working WinXP hvm was not starting up properly. When I looked into it further I found the following in /var/log/xen/qemu-dm.11384.log

domid: 20
qemu: the number of cpus is 1
/etc/xen/scripts/qemu-ifup: could not launch network script
Could not initialize device ‘tap’

Tap device cure (found here):

tunctl -t tap0

The final piece of the puzzle (since I’m using the routed script with xen)…

Comment out “brctl addif $2 $” from /etc/xen/scripts/qemu-ifup as mentioned by George in this mailing list thread.

UPDATE (2007Feb12): By doing the above two tasks, I was able to launch WinXP under Xen, but I did not have shorewall setup properly. To save time and money, I’m going with the simpler route of buying a hardware firewall/router. I will leave the information above incase it is useful to anyone (including myself) in the future.

Rescuing a Linux installation

Posted on : 30-01-2007 | By : Brandon W. King | In : Computers/IT, Error Fixes, Linux, Systems Administration

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In an attempt to save a system without doing a fresh reinstall by copying the contents from dying hard drive to new hard drive using external hard drive enclosure. This method seems to have worked well for me. I’m posting it as reference so others have a guide to work from and improve upon. I have only used this method once so make sure you know what you are doing if you follow the guide.

WARNING: Use the following formation at your own risk. Make sure you make proper backups. The following information may have errors or may not work properly and could possibly damage your system or cause the loss of data. Once again, use the following at your own risk. Research how to use each individual command so you know what you are doing.

Guide to moving a Debian or Ubuntu Linux installation from an old hard drive to a new hard drive without re-installing.

  1. Attach external hard drive
  2. Reboot computer into single user mode (i.e. rescue mode)
  3. Find the new device of the external hard drive (probably sda or sdb) dmesg | grep hd; dmesg | grep sd
  4. create new partions on new drive: fdisk /dev/sd(a,b, etc.)
    1. create swap partition
    2. create linux partition(s)
  5. initialize swap: mkswap
  6. create filesystem (I’m using ext3): mkfs.ext3
  7. Mount the new hard drive (referred to as /dev/sda2 from now on): mount -t ext3 /dev/sda2 /mnt
  8. Use debootstrap to get base install (ubuntu edgy example): debootstrap edgy /mnt http://us.archive.ubuntu.com/ubuntu
  9. Now the copy command: rsync -av –exclude=/dev –exclude=/sys –exclude=/mnt –exclude=/proc –exclude=/media / /mnt
  10. Make partition bootable: fdisk /dev/sda2 # use the ‘a’ option
  11. Shutdown system and put in the new drive.
  12. Get Grub working again:
    1. Insert Ubuntu or other Debian based live CD (Knoppix is a good choice too).
    2. Mount the new drive: mount -t ext3 /dev/hda2 /mnt
    3. Install grub: install-grub –root-directory=/mnt /dev/hda2
    4. chroot into new drive: chroot /mnt
    5. edit /boot/grub/menu.lst
      1. Update groot(hd0,) #if bootable partition changed (i.e. Was /dev/hda5 is now /dev/hda2… Old: groot(hd0,4) New: groot(hd0,1)
      2. Update kopt=root #if bootable partition changed (i.e. Was /dev/hda5 is now /dev/hda2… Old: kopt=root=UUID= or kopt=root=/dev/hda5 New: kopt=root=/dev/hda2 (NOTE: There is probably a way of getting the new UUID of the new partition, in which case you can just update the UUID option, but I don’t know enough about this yet to offer advice… Feel free to post a comment if you know more.)
    6. type: update-grub
  13. Reboot and hope everything works properly.

xen error: Error: Device 0 (vif) could not be connected. Backend device not found.

Posted on : 17-01-2007 | By : Brandon W. King | In : Computers/IT, Linux, Systems Administration, Virtual Machines

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Currently, I’m working on setting up Xen 3.0.3 on Debian Etch 64-bit. I installed the debian packages rebooted and used xen-tools to create a Debian etch guest domain. When I used xm create -c debian_etch_guest.cfg vmid=1 I got the following error:

Error: Device 0 (vif) could not be connected. Backend device not found.

I googled for the error and didn’t immediately find a solution to the problem (it may still be there in the search results), but as it turned out, the only thing I needed to do was install bridge-utils:

apt-get install bridge-utils

That’s it, now the guest domain boots without a problem.

CD Burning on Linux

Posted on : 20-12-2006 | By : Brandon W. King | In : Computers/IT, Linux, Software Endorsements

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Below is a screenshot I took from my setup for burning a copy of Debian Etch using K3b.

If anyone out there is looking for CD burning software for Linux, I would recommend K3b (k3b.org), which worked right out of the box (that being the apt-get box), auto-detected cd burner and write speed.


  • Used K3b in Ubuntu Edgy on an HP zd8000 Laptop.
  • Burned a copy of Debian Etch RC1 successfully.

Custom Debian Linux Kernel Debian package w/ initrd

Posted on : 06-12-2006 | By : Brandon W. King | In : Computers/IT, Error Fixes, Linux

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My attempt to build a new Debian Linux Kernel was thwarted by initrd! Thanks to Diane Trout mentioning that when using make-kpkg, to build a kernel image, doesn’t automatically make an initrd image. I investigated further and found out if you use –initrd, it will automatically generate the initrd image.

Below are the instructions for building a custom Debian Linux Kernel Debian package:

1) Install the following Debian packages (Need access to Universe repository for Ubuntu):

  • kernel-package
  • initrd-tools

2) Get the kernel source (choose version, I used 2.6.17):

apt-get install linux-source-2.6.17

3) Decompress /usr/src/linux-source-2.6.17.tar.bz2

4) cd /usr/src/linux-source-2.6.17

5) Switch to root if you haven’t done so already (sudo -s)

6) type ‘make menuconfig’ to configure your kernel

It may require installing libncurses5 and libcurses5-dev.

7) type ‘make-kpkg –revision 1.0 –append-to-version -custom –initrd kernel_image’

Feel free to change the revision number or and use something other than custom (or omit –revision and –append-to-version to use defaults).

8) type ‘cd ..’

9) dpkg –install linux-image-2.6.17-custom_1.0_amd64.deb

Except using the .deb package name which was generated on your computer.

10) Reboot and enjoy!