Ubuntu on technocracy

Improving VirtualBox performance

Fri, 14 Aug 2009 00:00:00 +0000

I run VirtualBox on an Ubuntu 64-bit Host with a 32-bit Windows XP guest. I was searching for a way to boost performance and came across this post related to configuring a SATA controller for drive access. Matt includes some great info there, but the step-by-step left something to be desired IMHO. Here are my revised instructions for configuring SATA support on your Win XP guest:

Start VirtualBox, but do not boot your guest.
Open Settings for your Win XP guest and select "Hard Disks"
Check "Enable Additional Controller" and choose "SATA (AHCI)"
Save your Settings changes and boot your guest
Inside your guest, download the appropriate SATA controller software from Intel
Install the Intel software
Shutdown your guest
Go back into VirtualBox Settings for your guest. Select Harddrives again.
Now change the slot associated with your Windows XP attachments/harddisk(s) from IDE to "SATA Port 0"
Save your settings
Start your guest and enjoy the performance boost!

Malfunctioning mouse after upgrade to Ubuntu 8.10

Sat, 18 Jul 2009 00:00:00 +0000

I experienced some intermittent and infuriating mouse malfunctions after my upgrade to Ubuntu 8.10. Single-clicks were interpreted as double-clicks, hilighted selections would lose focus, etc...

Connecting to Netscreen Series (NetScreen-5) VPN with Ubuntu 9.04 (Jaunty - AMD64)

Wed, 13 May 2009 00:00:00 +0000

I recently struggled through the details of establishing a VPN connection from my Ubuntu 64 desktop to a Juniper Networks Netscreen-5. There are a number of ways to skin the VPN cat in linux and I'm not going to detail them all here. I'll just tell you how I solved it.

Resolving Synergy mouse issues with Firefox after upgrade to Ubuntu 8.04

Fri, 03 Apr 2009 00:00:00 +0000

My desktop runs Ubuntu (64-bit) and I use Synergy to drive its keyboard and mouse over to various clients like my MacBook Pro.After my upgrade to Ubuntu 8.04 my Synergy-driven mouse exhibited truly bizarre behavior while interacting with Firefox on my Mac. DHTML didn't function normally, dropdown menus were inaccessible, flash interactions were also hit-or-miss...

At first I blamed Firefox since Safari exhibited no such issues, but after a bit of trial and error I decided to compile Synergy server from source on my Ubuntu box. I killed the Ubuntu packaged Synergy server and launched my self-compiled binary. The new server resolved all the issues.

Another win for open source software...

Removing duplicate music files with different names from a large directory free

Tue, 28 Oct 2008 00:00:00 +0000

During a recent Mac migration, I hosed my iTunes library and unintentionally generated hundreds of duplicate songs (the actual media files). The problem was exacerbated by the fact that a numeric was generally appended to the duplicate filenames so that I had directories full of files like the following:

/artist/album/song.mp3/artist/album/song 1.mp3/artist/album/song 2.mp3

Apple wasn't doing me any favors by injecting a space in the new names either....what a mess!

I stole a few ideas from this excellent forum thread and cobbled together a script to remove files based on exact byte counts and md5sum signatures. Here's the good stuff:

avahi-daemon blocks nfsd on Ubuntu

Fri, 06 Jun 2008 00:00:00 +0000

I just spent a morning attempting to fix a NFS mounting configuration that had been working flawlessly for over 6 months. My daemon log was showing this:

nfssvc: writing fds to kernel failed: errno 98 (Address already in use)

After much angst, I finally stumbled upon this posting that mentioned a conflict between avahi-daemon and NFSd. After a quick "apt-get remove avahi-daemon", all is well with the world.

Java webbrowser plugin for AMD64 Ubuntu

Mon, 29 Oct 2007 00:00:00 +0000

There is now (finally) a fix for Java applet support on AMD64 Ubuntu. Try the following:

sudo apt-get build-dep icedtea-java7-pluginsudo apt-get -b source icedtea-java7-plugin icedtea-java7-bin icedtea-java7-jre icedtea-java7-jdksudo dpkg -i icedtea-java7-*deb

Thanks to Fabien Lusseau for the tip in his comment here

Mounting an Ubuntu NFS share on RedHat Enterprise with firewalls on both

Sat, 20 Oct 2007 00:00:00 +0000

It can be tough making NFS play nice amongst different distros and firewalls. I'm sharing my Eclipse workspace on my Ubuntu (Debian) desktop with my CentOS (Redhat Enterprise) server. (That's not a mistake, my server is actually my NFS client in this scenario. You could easily swap these roles if you wish)

DEBIAN:I used port numbers and config instructions at http://wiki.debian.org/?SecuringNFSFollow those instructions exactly and you'll have a NFS server configuration that uses static ports (instead of random assignements)REDHAT:1. Create the file "/etc/sysconfig/nfs" and add the following contents:STATD_PORT=32765STATD_OUTGOING_PORT=32766LOCKD_TCPPORT=32768LOCKD_UDPPORT=32768MOUNTD_PORT=327672. (Probably not necessary for most, but here for completeness) Append the following to the file "/etc/services":rquotad 32769/tcp # rpc.rquotad tcp portrquotad 32769/udp # rpc.rquotad udp port3. Restart the nfslock service:/etc/init.d/nfslock restart4. Run /usr/sbin/rpcinfo -p and make sure all the ports above have changed and match their ubuntu numbers. (/usr/bin/rpcinfo on ubuntu)5. I run firestarter on Ubuntu which is exporting my NFS share. I added the following policy rules for inbound traffic:Allow 32767 (from my client machine's IP)Allow 2049 (from my client machine's IP)Allow 111 (from my client machine's IP)

Assuming you allow all outbound traffic on your client (I recommend this excellent iptables config file rc.firewall_023.txt), you should now be able to mount the NFS share on the Redhat box.