!!! Raspberry Pi


A new gadget, see [http://www.raspberrypi.org].

[{TableOfContents }]



!! Installation , operation.

Make sure you have a micro USB power supply that offers enough current (at least 700 mA) and good voltage. Use a voltmeter in case of doubt.\\
I had a 2 GB SD Card (the absolute minimum), and installed the default __Raspbian “wheezy”__ on it, see [http://www.raspberrypi.org/downloads].
\\
After downloading and verifying the SHA1, you can unzip it and also check the partitions in it :
{{{
metskem@athena ~/Downloads $ ls -l 2012-12-16-wheezy-raspbian.img 
-rw-r--r-- 1 metskem metskem 1939865600 Jan  4 20:52 2012-12-16-wheezy-raspbian.img
metskem@athena ~/Downloads $ file 2012-12-16-wheezy-raspbian.img 
metskem@athena ~/Downloads $ sudo dd if=2012-12-16-wheezy-raspbian.img of=/dev/sdb bs=4M
462+1 records in
462+1 records out
1939865600 bytes (1.9 GB) copied, 243.748 s, 8.0 MB/s
metskem@athena ~/Downloads $
}}}

Stick the network cable in, and stick the power cable in.\\
You should see the red LED (PWR) lighting up, and also after a few seconds all (4) other green and yellow LEDs.\\
If not, either your power supply is insufficient or your SD card is not properly formatted with the right 2 partitions (that was the case with me the first time).

After booting up the first challenge is to find out the IP address it got (DHCP), so I wrote a small shell script the iterates over all 25 addresses in the range and tries to ''ssh pi@${address} ''.

After first login (user pi password raspberry), you are advised to run the __''sudo raspi-config''__ script. 
I did that to 
* Expand root partition to fill SD card
* set the Timezone
* set the Locale
* run an update (apt-get)

!! Network config

Because pi is running as a server, it needs a static IP address, so change ''/etc/network/interfaces'' and edited the line for ''eth0'':
{{{
#iface eth0 inet dhcp
iface eth0 inet static
address 10.0.0.186
netmask 255.255.255.0
gateway 10.0.0.138
}}}

!! Some "screenshots"

{{{
metskem@athena ~/Downloads $ ssh pi@10.0.0.171
Linux raspberrypi 3.2.27+ #250 PREEMPT Thu Oct 18 19:03:02 BST 2012 armv6l

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Sat Jan  5 14:59:34 2013 from 10.0.0.164
}}}
{{{
pi@raspberrypi ~ $ df -h
Filesystem      Size  Used Avail Use% Mounted on
rootfs          1.8G  1.5G  238M  86% /
/dev/root       1.8G  1.5G  238M  86% /
devtmpfs        220M     0  220M   0% /dev
tmpfs            44M  200K   44M   1% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            88M     0   88M   0% /run/shm
/dev/mmcblk0p1   56M   17M   40M  30% /boot
}}}
{{{
pi@raspberrypi ~ $ sudo fdisk -l

Disk /dev/mmcblk0: 1967 MB, 1967128576 bytes
4 heads, 16 sectors/track, 60032 cylinders, total 3842048 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00017b69

        Device Boot      Start         End      Blocks   Id  System
/dev/mmcblk0p1            8192      122879       57344    c  W95 FAT32 (LBA)
/dev/mmcblk0p2          122880     3842047     1859584   83  Linux
}}}
{{{
pi@raspberrypi ~ $ cat /proc/cpuinfo
Processor	: ARMv6-compatible processor rev 7 (v6l)
BogoMIPS	: 697.95
Features	: swp half thumb fastmult vfp edsp java tls 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xb76
CPU revision	: 7

Hardware	: BCM2708
Revision	: 000e
Serial		: 0000000095619558
}}}
{{{
pi@raspberrypi ~ $ uname -a
Linux raspberrypi 3.2.27+ #250 PREEMPT Thu Oct 18 19:03:02 BST 2012 armv6l GNU/Linux
pi@raspberrypi ~ $ 
}}}
 
!! Reboot after plugging in USB stick

Because I only had a 2GB SD Card (I already ordered a 16GB class 10 card, next week in) and want to put more stuff on it, I inserted an extra USB stick in, this immediately made 4 of 5 LEDs go out. I suspect this required a short peak of current making the voltage reduce too much. It did automatically reboot and was back up in about 30 seconds.

!! Performance

The performance of the thing is (as expected) not as we are used to with our Intel boxes. Also having a slow SD card makes the thing even slower. If you use ''top'' you see a lot of IOWAIT.

!! Installed stuff

* locate
* vim
* default-jre-headless  (and that just fitted on the SD card, only 88MB free)


!! JSPWiki

The goal is to see how JSPWiki runs on it.\\
We need a container first, so unzipped the latest tomcat (7.0.34) to /mnt/sda1/apache-tomcat-7.0.34.\\
The created the webapps/wiki directory and unzipped the latest (2.9.1-svn-11) and tweaked jspwiki.properties (baseURL and pageDir and attachmentDIR).

Firing up the stuff, takes a loooong time, see attached [jspwiki.log], but it just works (as expected :-) )

Created an extra DNS alias for my domain and added some proxy statements to my main host, the wiki is now accessible at  [http://raspberrypi.computerhok.nl/wiki] 

! Performance tomcat / JSPWiki

See for details the [logfile|jspwiki.log], but some performance related messages:
%%small
{{{
INFO: Server startup in 103644 ms

2013-01-05 16:48:29,964 [JSPWiki Lucene Indexer] INFO org.apache.wiki.search.LuceneSearchProvider  - Full Lucene index finished in 10067 milliseconds.

2013-01-05 16:54:50,841 [WatchDog for 'JSPWiki'] INFO org.apache.wiki.util.WatchDog  - Watchable 'http-bio-8080-exec-1' exceeded timeout in state 'Generating VIEW response for WikiPage [JSPWiki:Main,ver=-1,mod=Sat Jan 05 14:31:16 CET 2013]' by 17 secondsEnable DEBUG-level logging to see stack traces.

}}}
%%
You also notice the first time you get to the wiki and all JSP's have to be compiled, that takes several minutes !