When doing matrix calcualtions it’s handy to do a comparison with a calculator. I’ve made two guides showing the basic steps for Casio and Texas Instruments calculators.
The guides are in Norwegian and I actually got it published for the MA-109 course at UiA. They might be useful for others too.
The new Android based device, called Droid, has just been announced. And it has a cool sound when a SMS is received.
To use the sound as a text message-tone on an iPhone, you need a jailbroken device and a AIFF version of the file. Download the already converted and corretly named file:
Or convert it yourself. In iTunes change the Import settings in Preferences to AIFF, add the droid sound to the iTunes library and right-click it, pick Convert to AIFF, drag the new AIFF file to the desktop, rename it to sms-received6.caf.
Connect to the iPhone via SCP and go to /System/Library/Audio/UISounds/. Rename the existing sms-received6.caf to sms-received6-org.caf, and upload the new droid sms-received6.caf. Go into Settings, Sounds, New Text Message, and pick Electronic as the SMS sound. Voila!
To use it as a ringtone, just sync this droid-alert.m4r with the iPhone in iTunes.
I’m trying out new filesystems for the drives going into the file-server. After relaying on ext3 for the last years, I’ve always wanted to figure out of there’s a better FS more suitable for storing large files.
The alternatives are XFS, ReiserFS, JFS, Ext3, and Ext4. Ext3 is excellent is an excellent system boot FS and for lots of smal files, but not as efficient for larger files.
Drive: Hitachi 7K1000.B 1TB via Promise SATA300 TX2plus PCI card (I know)
Software: Bonnie++ 1.03d harddrive benchmark, executed by bonnie++ -u 500:500
hdparm – for reference, shows the cache and disk read speeds
Test done using: hdparm -tT /dev/sda
The test will first create then rewrite a 1GB file.
Ext3
Formatted using: mkfs.ext3 -j -c 1 /dev/sda1
XFS
Formatted using: mkfs.xfs -f /dev/sda1
XFS tuned
Formatted using: mkfs.xfs -f -l size=128m,lazy-count=1 /dev/sda1
ReiserFS3
Formatted using: mkfs.reiserfs /dev/sda1
JFS
Formatted using: mkfs.jfs /dev/sda1
The benchmarks look good, but they only tell a small part of the puzzle. It’s important to not to forget the stability and reliability record for each FS. How it will behave in a power failure and unexpected situations? From experience will ext3/4 perform great in these scenarios, XFS, ReiseFS, and JFS not so much according to forum reports.
More testing and experience is needed to figure out how these filesystems stack up.