Benchmark is a simple ‘dd’ sequential read and write.

write: dd if=/dev/zero of=/dev/md2 bs=1M
read: dd if=/dev/md2 of=/dev/null bs=1M

mdadm –create /dev/md2 –verbose –level=10 –layout=n2 –raid-devices=4 /dev/sd[ftlm]1

mdadm –create /dev/md2 –verbose –level=10 –layout=f2 –raid-devices=4 /dev/sd[ftlm]1

mdadm –create /dev/md2 –verbose –level=10 –layout=o2 –raid-devices=4 /dev/sd[ftlm]1

And more comparisons:

RAID1 (PCI)

write: 38.9 MB/s
read: 64.8 MB/s

Single Disk (PCI)

write: 59.4 MB/s
read: 71.9 MB/s

1. Install Tripwire. Say Yes to everything, and create some passwords.

% sudo apt-get install tripwire
% sudo tripwire -m i

2. Fix the policy. I was getting many errors that looked like:

### Warning: File system error.
### Filename: /root/.Xauthority
### No such file or directory

I removed the non-existent files from the policy file with the following commands:

% sudo cp /etc/tripwire/twpol.txt /etc/tripwire/twpol.txt.bak
% sudo vim /etc/tripwire/twpol.txt
% sudo tripwire --update-policy -Z low /etc/tripwire/twpol.txt

Later, when you need to update the database, such as after running updates (adjust the date and number from then end of the file, or sometimes you can just drop the whole -r flag):

% sudo tripwire -m u -r /var/lib/tripwire/report/closetbox64-20071223-133927.twr

By default, Tripwire will be set to email whenever it sees changes. To quickly check the status, run:

% sudo tripwire --check

Edit /etc/rc.local, add your command, make sure it doesn’t create any output. This is my command:

su rt -c “fetchmail -d 300″ > /dev/null 2>&1

It starts a background fetchmail process as the “rt” user, just as the Request Tracker documentation states.

# cat /proc/mdstat

md0 : active raid5 sdf1[7] sdb1[0] sde1[5] sdg1[4] sdh1[3] sdd1[2] sdc1[1]
1465175424 blocks level 5, 64k chunk, algorithm 2 [7/6] [UUUUUU_]
[>....................] recovery = 1.3% (3331200/244195904) finish=2357.0min speed=1700K/sec

Ouch. Two files are used to control the speed of rebuilding RAID arrays in Linux.

/proc/sys/dev/raid/speed_limit_min
/proc/sys/dev/raid/speed_limit_max

Even though my _max file is set to 200,000K/sec and my system is not doing anything, my RAID 5 rebuild process is hovering around the _min rebuild speed, of 1,000K/sec. With my setup this will take approximately 40 hours to complete, which is too long for me to wait. So, I pushed the _min speed up to 10,000K/sec, which will now take 6 hours to finish, and use slightly more of my system’s idle resources.

root# echo “10000″ > /proc/sys/dev/raid/speed_limit_min

Later I set _min to 50,000K/sec, and the rebuild speed topped out at 25,000K/sec.

#cat /proc/mdstat

Personalities : [raid5]
md0 : active raid5 sdf1[7] sdb1[0] sde1[5] sdg1[4] sdh1[3] sdd1[2] sdc1[1]
1465175424 blocks level 5, 64k chunk, algorithm 2 [7/6] [UUUUUU_]
[=>...................] recovery = 5.1% (12661840/244195904) finish=149.9min speed=25726K/sec

The rebuild took less than 3 hours, down from the original 40.

1. sudo apt-get install libapache2-mod-python python-mysqldb python-docutils
2. wget http://www.djangoproject.com/download/0.95/tarball/
3. tar xfz Django-0.95.tar.gz
4. cd Django-0.95
5. sudo python ez_setup.py
   
6. sudo python setup.py install
7. start creating a Django app
   

Other notes:

• python-setuptools included with Dapper is not recent enough for Django 0.95

NETDEV WATCHDOG: eth0: transmit timed out
NETDEV WATCHDOG: eth0: transmit timed out
NETDEV WATCHDOG: eth0: transmit timed out

I’m not yet sure why my network card stopped working, Google or the Ubuntu forums should help, or I could just refer back to my pre-rma’d motherboard and remember that the Marvell skge network controller died on that motherboard completely, and move to other built in network card on the mobo, by NVIDIA. If all that fails, dropping some money on a quality Intel NIC will solve the problem. Unless the problem exists in my switch.

Update: Switching the the integrated NVIDIA network interface appears to have fixed this issue. Hooray for workarounds.

1. On Typo, go into the admin section, set rss feeds to 1000 or something high.
2. On your computer, download your RSS feed to a text file (I used wget).
3. On WordPress, go to import, choose RSS, and find the file you downloaded.

That’s it.

• Rails 1.1.2
• Lighttpd 1.4.11
• MySQL 5.0.21 or 4.1.15
• Ruby 1.8.4
• Ruby-FCGI 0.8.6
• Ruby-MySQL 2.7

This means that after a 10 minute server install of Ubuntu, one can uncomment the universe repo in /etc/apt/sources.list and issue the following command to setup at capable and competent Rails server environment:

sudo apt-get install ruby1.8 mysql-server rails lighttpd libmysql-ruby1.8 libfcgi-ruby1.8

Then copy your Rails app over and configure it in Lightty you’re off. Now to find a hosting company which supports Ubuntu…

Update: Rubygems can be useful, but it isn’t in the standard repos. Instead, I downloaded and compiled rubygems-0.9.0.tgz.

Update2: I removed the Ubuntu-supplied rails and instead used rails from rubygems.