22 July 2005

Sound Config on Linux

This has to be the easiest thing I've had to do to configure my linux box. Using Slackware 10.1, I logged in as root and ran the alsaconf utility. This auto-detected the sound card and even modified the startup files. I ran it from a terminal window under KDE and straight after, it was able to play a couple of .wav files on the desktop. :)

Unfortunately gnome-meeting is still not working properly yet :(

21 July 2005

Project Week?

So far this week I seem to have spent quite a lot of time doing 1-2-1 tutorials with students who are about to submit their dissertations for comments. The problems have been very varied in terms of content and complexity.

Monday
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I spent some time helping out Jermaine with his web-streaming project (again). He seems to have taken notice about having to have his project on one of our servers here for marking so I had to set up some space for him and check it was serving jsp pages.

I spent the rest of the day evaluating web-cam software (for surveillance use)and reading up about wi-fi antenna. There appears to be a lot of web-cam software available so I set out specific criteria for selection.

I wanted:
1) A program that could take timed pictures and upload them to a remote ftp site
2) Some sort of motion detection
3) Have the ability to number uploaded pictures
4) Be cheap or relatively low cost.
5) Be easy to use

There were quite a few programs which passed the selection process although there were many which didn't. The ones which seemed like they might be useful are:


Conquer Cam
ChillCam
Web-cam Control Centre
Crime Catcher


Of these I think ConquerCam is the winner at $10 USD (about £5.70). At this point I should also mention CatSpy. This is currently freeware and stores video clips instead of single frames. It also has motion detection and is easy to set-up.


Tuesday
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Today I got a wi-fi card working on linux by downloading and compiling the driver and configuring it. While I did this for an old 802.11b card I brought in from home, the principles are the same for any card so I will now be able to support Bob if he decides to integrate wireless into his linux modules.

I got the netgear MA-101 (rev. B) amtel based card running on Slackware by using this site, which proved to be incredibly useful. I followed the sites instuctions to compile and install the driver. The configuration was then just a few conmmands which I added into my /etc/rc.d/rc.local file to get the wifi card to power up after booting:


ifconfig atml0 192.168.10.1 netmask 255.255.255.0 broadcast 192.168.10.254
ifconfig atml0 up

iwconfig atml0 essid "Office"
iwconfig atml0 channel 4
iwconfig atml0 mode ad-hoc

/usr/sbin/dhcpd atml0


The ifconfig commands set up the wi-fi cards IP settings and bring the interface UP. The iwconfig commands access the wi-fi extensions in linux and set up the station id, channel and in this case set the card to ad-hoc (ie connects to any other wi-fi link without requiring an access point). The usr/sbin/dhcpd command sets up a DHCP service on the card so connecting machines can obtain their own IP settings from this machine. This is not very secure but the machine is not connected to the network so it's ok. The addresses given can be changed by altering the etc/dhcpd.conf file. I changed this to give out addresses in the range 192.168.10.32 to 192.168.10.128.

In this case the slackware box was acting as a fixed point in the network. I could have made it a client machine by using dhcpcd atml0 which tells the interface to get it's IP address from another dhcp server. Using this with another network card (PCI or onboard) would be the starting point of a home linux router/firewall system. Using dhcpcd eth0 for example would get the linux machines IP address (and other info) from the service providers dhcp server.

Wednesday
=========

Today I did a 1-2-1 tutorial with a Mr Abubaker (an MSc student from the Stafford campus) on how to embed an MS project Gantt chart into word as an imported object. MS really don't make it easy to format the object so I finally suggested he use printkey to grab screen-dumps which could be inserted into his document.

I also prepared a ghost bootup disk with drivers for a Dlink 530Tx network card which I set up on Lynn's machine to create a backup copy of her hard-drive (problem diagnosed on Tuesday 12th. Replacement drive from Pheonix computers would not arrive for three weeks so Mel has found a replacement 10GB drive for now). I set the ghost session up after 5pm so as not to inconvenience Lynn during the day.

I also helped out another student who didn't know how to backup his project onto CD. We could create a hand-out for this but I suspect the students actually find it reassuring to have us there at the time. If they get it wrong it is easy to ruin the CD.

Thursday
========

Today Mr Abubaker has been back and needed a quick refresher on certain functions of MS word. He asked for help with borders around pictures amongst other things. He left seeming both happy and grateful for the assistance.

Lynns replacement hard-drive has been created using one of the open machines from the hardware lab and will be swapped over later on this afternoon.

14 July 2005

Win Tomcat & Slaxx

I spent most of this morning helping a student with his project. J has a tendancy to go off at a tangent at the earliest opportunity. He's also had some problems with his PC lately and brought it in again.

To start with I went through windows media encoder with him using my own (recently purchased) webcam. It didn't take long to set up as the wizard did most of the work. I just had to specify to pull the stream from the encoder rather than a windows server. J seemed confident enough to know how this works and he did have some video clips on his PC suggesting that he had actually used it to capture some video of his own.

Earlier in the year I spent some time setting up the Tomcat JSP server on his machine and it looks like somewhere along the lines it got trashed. Luckily I kept my install instructions so I backed up his files, uninstalled what was left of the original server and reinstalled it all from the beginning (complete with Jonathans demo site).

J then showed me his media streaming page which had a slight error on it. He had somehow (or maybe Dreamweaver had) missed a closing ">" after the embed section. It took a while to find but eventually we got his page displaying the video stream from my machine and then I copied his page and showed him the part where a filename can be specified to view a file rather than a live stream. He seemed quite pleased with the progress and inquired about a user/password database system. I told him I couldn't do that for him and referred him to the JSP module web-pages.

After lunch I started looking at Slaxx. In particular one aspect of Slaxx seems to be causing me some irritation at the moment. I have been trying to connect to an external server but I just couldn't get it to work properly.

I found lots of articles about setting up network cards and routing tables (the best of which is here). I still couldn't get it to connect to the local gateway though and it kept coming back with a SIOCADDRT error. I tried everything listed in the article but Slaxx refuses to connect. I finally gave up and tried my Ubuntu live CD instead and was impressed when it managed to set up the gateway without any problems at all. Strange that Slaxx would let me ping any machines on the local subnet but nothing outside it.

12 July 2005

Why computers and heatwaves don't mix

Today I ended up reinstalling a video driver on a machine which has suffered some corruption on the hard-drive. The fault seems to have occured because the screen display driver was located on the part of the disk-drive which failed. The usual sign of a dying drive is lots of found.00* files created by MS's fixdisk utility trying to recover damaged sectors (chunks of data) on the drive.

Normally I would have said "Yep... dying drive" and found/ordered a replacement but then I thought "Could this be the effect of heat?". Our office for example is currently 30.8°C. This is because we are opposite an air-conditioned lab with two fans near the door, another in the corridor and then two smaller fans blowing into our office. Although it feels cooler to me, the articles I've read on the topic suggest the fans are just evaporating moisture on my skin. Since computers don't generate this moisture, they don't lose heat from its evaporation.

So I fired up the intel system monitor. My cpu (P4 3Ghz) is running at 44°C. My motherboard has two other temp sensors onboard which are reading 39°C and 43°C. My system has a couple of extra fans which I fitted myself to improve the airflow. My maxtor hard-drive specifications say it will run up to 55°. The question is, how close to that would this machine be if I hadn't put extra fans in? Even then is the drive rock-solid at 54° and then it suddenly dies at 55° or is there a sliding scale (performance declines from 50° onwards?)

The other problem is... how do you monitor a hard-drives temperature? For home systems it's easy; you go out spend £30 on a fan controller with temperature sensors but that's not practical or economical for 200 machines. It's also not necessary for 3 labs which have air conditioning. However the machine having the problem is a staff machine in an office. The windows are open but there's very little wind. I'm 99.9% certain the machine won't have rounded IDE cables inside which would have helped. Although it's a lower spec machine I suspect it's internal temperature is probably higher than mine.

The best resource I've found on this subject yet is on the Antec web-site.
Some of it is common sense, some of it is too expensive to implement but some of it is really useful

11 July 2005

Wireless & Warchalking

After a long weekend (and an extra day off on friday) it was straight back into the wireless networking arena today as me & Bob attempted to set up an example of a secure (sic) network.

The problem is that all the wifi devices we have are different. My SanDisk 256mb+wifi card seems to be the most restrictive as it doesn't seem to support wpa-psk properly. We finally got it to work with wep (64-bit) although it didn't seem to work with the newer more secure protocols. It looks like we will need to set-up a radius server to use either WPA or 802.1X protocols. Of course we don't just have radius servers propping doors open so it means installing one from scratch.

Bob is slightly more security conscious now suggesting he may have read the article I sent him about why the WEP protocol isn't very secure. In the interests of security I have also tracked down a couple of articles on wardriving, specifically so we can keep an eye out for the appearance of chalk symbols appearing on our buildings. I think this is unlikely as the wireless equipment is not used for any length of time but better to be informed about these things.

The article with the symbols can be found here.

I was also reminded of a utility which detects wifi networks called net-stumbler. It's been a long time since I last looked at this but it seems they now have a PDA version so I hope to try it out very soon.

Another site which I think may become useful is Wi-Fi Zonefinder. Although we should not really be encouraging our students to frequent the local bars, it turns out that the Roebuck (approx 100 yards from the front door) is listed as a wi-fi hotspot.

5 July 2005

MySQL revisited

Today the big issue in our office is software and our lab images for this September. Being public sector we always need more than we can afford. As a result the excellent but no-longer-free MySQL-front has had to go. Adrian was not impressed to hear the license was about 14 items below the cut-off point in the priorities list.

All is not lost though. A while back I was looking at alternative front-ends and this seemed like a good day to have another look at sqlyog. It's been a while since I looked at it, but since this is what I recommended Helen should use last month I thought it would be useful to try some basic functions.

Despite not using mysql for a while I didn't have any problems performing basic functions in yog. I managed to create tables, add data, export it as a sql dump file, delete it and then re-import it again. If anything yog is possibly slightly easier than front imho.

The interesting bit occured when I tried to access an external server. It looks like port 3306 (mysql default) is blocked at the firewall or at some point along the route. I could login using SSH and tried changing the default port in the my.cnf file to a 5-digit number. Sadly this port was also blocked which lead to me investigating other methods of remote admin on mysql servers.

The first method I attempted is actually built into yog. Html tunnelling uses a php web-page which you copy to your user area on the mysql server (I think this assumes the mysql and php are hosted on the same machine). It looked like an interesting idea until I discovered this feature is only available on the retail version (so back to square one).

Yog's big mistake was to mention another system on their web-site called PHPmyAdmin. This is a php web-site which you put into a directory on the host (again will need to check if this works when the sql and php hosts differ). All I needed to do was edit the config.inc.php file and enter the host name and mysql credentials and it just worked.

The interface may be a little slower than using yog locally, but I managed to dump an external database to my local machine without too much fuss. It is worth remembering I did this as admin so we'll need to check if students could use this remotely.

4 July 2005

Airwaves and Technoreps

Friday was a fairly busy day. Our radio station friends finally moved into the building so there was an initial process of moving them in which involved me helping to shift boxes and equipment, sorting out keys and access codes, checking network port connectivity (for which a linux laptop was incredibly useful) and chasing up a problem with the phone lines which I then discovered was actually a problem with a telephone.

In the afternoon I was in an informal meeting with Mick and Paul Bossons to discuss machines and lab equipment with Rob Crowther from Pheonix Computers (our new equipment supplier?). We discussed the demo machine we had to try out and pointed them towards what we would really like to have here. It will be interesting to see what they come back to us with next.

1 July 2005

Open days are great

After my day off on wednesday I returned yesterday and was told we were having an open day. It would have been a total surprise had my wife not pointed out the AA signs on the way in to work.

So I spent the morning creating & printing signs to direct people towards the labs (using publisher) and supporting the staff by enabling the open day user account in active directory and starting up the sip server (which I set up during last semester)for a VOIP demo in the network lab.

In the afternoon I spent some time trying out the Ubuntu linux live CD and noticed a program called gnome-meeting (similar to net-meeting). I thought this might be useful for the VOIP demos/modules so I experimented with it until I got it working and then I mentioned it to Jonathan and Michael.

I also came across a strange problem with XP's firewall in SP2 yesterday. Some spyware appeared to cripple it even after the spyware was removed. Every time I tried to start up the firewall in security centre it would crash with a 10047 error and prompt me to start the firewall service manually from control panel. This also failed to fix it. I found an article on google explaining that the spyware had added a layer service and although MS-antispy had removed the spyware it doesn't fix the service issue. The fix is fairly simple though. From a dos prompt, type in 'netsh winsock reset' and the service can be restarted.