Archive for category Linux
I have been revising my file server/firewall/ZoneMinder system that I described in some of my first blog posts and it has all gone pretty smoothly. I bought a new motherboard and CPU, mostly to get gigabit Ethernet support, but in the hope that ZoneMinder would work better with my IP camera (another story for later post). The new board is an Asus G41-based M-ATX part with a 2.9GHz Pentium Dual-Core E6500 on it. The bump in CPU power from a 1.2GHz Pentium 3 is substantial. I was able to reuse the old HP box and power supply, and power consumption has only gone up from 45W to ~53W, which is pretty good. Its running Ubuntu Lucid Lynx (10.04) and installation and setup went very smoothly apart from some confusion with shorewall, whose default two-interface setup assumes that the local net is eth1 and the Internet is on eth0. I have it the other way around and you need to change all the config files.
This post, however, is about a new idea I wanted to try, which was to install my old Telecom CDMA phone in the server cupboard and use it to send and receive text messages to and from the server.
On the face of it this didn’t look difficult. There is a Linux/Windows/MacOS package called gnokii that does practically everything with a phone, provided that the phone supports Bluetooth or has a data cable, that you could possibly want. My Nokia 6165i has Bluetooth, so the first step was to buy a cheap Bluetooth adapter (Dick Smith, $20), plug it in, and fire up Bluetooth support:
sudo apt-get install bluez
Once I had that, I turned on the phone, told it to be discoverable on Bluetooth (down in Settings/Connectivity/Bluetooth/Bluetooth Settings) and told Bluetooth to look for it:
00:12:D1:3F:00:8F Michael H 6165i
It found it! Now to get gnokii:
sudo apt-get install gnokii
The version of gnokii that comes with Ubuntu 10.04 is 0.6.28, which has its preferences in ~/.gnokiirc or /etc/gnokiirc. Later versions change this, but for the moment it was enough to edit the heavily commented /etc/gnokiirc and use the Bluetooth ID given by hcitool so that the following lines were active:
port = 00:12:d1:3f:00:8f
model = series40
connection = bluetooth
debug = on
Debug is useful if you run into problems, as I did…
should then talk to the phone, whereupon we run into our first problem. The phone needs to pair to the Bluetooth transceiver on the PC, and if we were running desktop Ubuntu a nice dialog would come up on the desktop as well as the phone, we enter the same PIN into each dialog and all would be well. But this is running on a file server and I can’t do that. Some Googling eventually found a solution, which is to use one of the bluez examples to get the PIN code handshake done:
sudo /usr/share/doc/bluez/examples/simple-agent hci0 00:12:d1:3f:00:8f
This prompts for the PIN code, you enter it, the phone prompts, you enter the same number, all is well.
Now sending a text message should be as simple as:
echo “This is a text message from the file server” | gnokii –sendsms number -r
But life isn’t that simple. It seems to work, but the text messages simply don’t go. It took a good deal of debugging, updating, and fiddling about before I discovered the simple truth:
gnokii doesn’t support CDMA phones. CDMA is an older technology and the commands to send text messages are there — but subtly different. The only thing that might have worked was using gnokii AT mode, which I could get at by changing model = series40 to model = AT in the preferences. But the answer to that is short and final:
PDU mode is not supported by the phone. This mobile supports only TEXT mode
while gnokii supports only PDU mode.
SMS Send failed (Unknown error – well better than nothing!!)
So there we are, it isn’t going to work. It wasn’t going to work for long anyway, as the old CDMA network is going to be turned off next year, so the next step is to buy a GSM Bluetooth phone and try again (ones with cracked but otherwise functional screens can be had very cheap on Trademe, I see…). I hope to extend this post with better news at some point in the future.
I have recently acquired one of the newly popular netbook machines, an Asus Eee 1000HA. This is one of a startling variety of Asus Eee models which seem to be being turned out as quickly as Asus can come up with new arrangements of netbook components. This particular version has a 10″ screen, 1G of RAM and a 160G hard drive. It comes with Windows XP.
Windows XP is all very well, but I wanted to try running Linux on the Eee as well. 160G of hard drive is more than enough to run two different operating systems, so why not? There are several Linux distributions specifically designed for the Eee, so this should be easy, you might think. As it turns out, its not completely straightforward. Hence this post.
The first hurdle you encounter is that the Eee doesn’t have an optical drive, so there is no way to burn a CD and boot from it, which is the usual way to install Linux. The 1000HA does however have USB ports and an SD card slot. It turns out it is capable of booting from either a USB flash drive or an SD card; I happened to have an 4Gbyte SDHC card which I acquired for backup already in the SD slot. I decided to install the aptly-named Eeebuntu 2.0 Standard distribution via this card.
So, under Windows, it was simply a matter of downloading the eebuntu-2.0-standard.iso file (880Mbyte). The .iso file is an archive file containing a bootable disk image, so you can’t just copy it onto the SD card and expect it to boot. An application called UNetbootin is needed to unpack it onto the SD card correctly; I downloaded unetbootin-windows-312.exe and ran it. UNetbootin presents a single window where you can select Diskimage format, and browse to select the eebuntu .iso file. The SD card appears as a USB drive at letter I:\ (UNetbootin is clever enough to preselect this for you). Clicking on OK sets UNetbootin running copying the .iso across to the SD card, which takes several minutes and may appear to hang at the extra-large filesystem.squashfs file.
Once this process completes, click on the ‘Reboot Now’ option that UNetbootin conveniently presents and as soon as Windows has shut down, hold down the ESC key. As the Eee starts up it should bring up the boot device menu. The SD card is described rather misleadingly as “USB:Single Flash Reader”. Select this and the UNetbootin menu will follow. Select ‘Default’, or wait for it select itself for you, and the Eeebuntu splash screen should follow. After a moment or so the Eeebuntu desktop comes up with the ‘Install’ icon at the top left. Opening this starts the installer. This asks some straightforward questions up to the point where it asks how to partition the disk.
Here we need to be a bit careful, because the disk layout is not quite what the installer expects. Asus for some reason divides the disk into three usable partitions; the first 80Gbyte partition contains Windows XP and all its associated files. The second is also formatted for Windows, but is empty and appears under XP as the D: drive. The third is a recovery partition for booting from when Windows borks itself as it sometimes does. The installer will default to resizing the first Windows partition to 17.5Gbyte and installing Eeebuntu in the remaining space. This is workable, but not very even-handed. I prefer to install Eeebuntu over the unused second Windows partition. To do this — assuming that your D: drive under XP is empty — select the Manual option and click Forward.
In the next dialog, select the second partition (/dev/sda2, about 65711Mbyte) and click on ‘Delete partition’. This is necessary because the partition is formatted for NTFS, which Ubuntu can’t install to. You will also need a swap partition, and we must make space for that. Select the resulting free space and click ‘New partition’. Make a logical swap area partition that is larger than your RAM size (1024Mbyte in my case) I used a rather arbitrary 3000 Mbyte. Then make a logical ext3 partition with a mount point of ‘/’ covering the remaining 62709 Mbytes. These should be /dev/sda5 and /dev/sda6. Select the format checkbox for the ext3 partition. Click Forward only after checking the above carefully as a mistake here could ruin your Windows install.
After answering a few more questions the install should run smoothly. On restarting (you can ignore the instruction to remove the nonexistent disc and close the nonexistent tray and just hit Enter) the Eee should display the Grub boot menu that allows you to select Ubuntu (or just wait and it will default to Ubuntu itself)
All is not completely plain sailing with Eeebuntu from the start, however.
Your first stop should be to plug into a wired LAN with Internet access and run the Update Manager. This will offer to do a bunch of updates (151 when I tried). For some reason it will complain that these can’t be authenticated when you click on Apply; you have to ignore this and apply anyway. Restart.
Under Applications/System Tools you will find an application called Eeebuntu Config. You should run it. It doesn’t have a setting for the Eee 1000HA (or it didn’t when I tried, you might get an updated version) I selected the 1000H, clicked on ALL and Execute. This runs a bunch of scripts that should customise Ubuntu better for the Eee.
If you start Firefox you may be startled by a license agreement for an add-on called DownThemAll, which you have to accept as it comes up again and again if you try to decline it. This was mistakenly added to Eeebuntu when it was built. You can remove it by accepting the license agreement, then clicking Disable and Restart Firefox in the Add-ons window that comes up when you do so.
The grub boot menu can be made friendlier (and you can pick what it defaults to and when) by editing /boot/grub/menu.lst. This needs to be done with supervisor privileges; I started a terminal session and entered ‘sudo gedit /boot/grub/menu.lst’ which gives you a nice visual editor. The file is reasonable self-explanatory.
The mouse pointer when busy is for some reason a rather ugly monochrome wristwatch instead of the normal Ubuntu rotating pattern. I haven’t been able to figure out why so far.
Wireless performance is, irritatingly enough, not very good. Signal strengths are lower and performance is spottier than Windows XP, by a considerable margin. You might wonder how such a thing is possible. It turns out to be because the open-source ath5k drivers for the onboard 802.11 wireless card don’t work very well – Atheros, who make the wireless chip, don’t distribute detailed information about it, or driver source code. So the open-source driver has been written in the dark, as it were, and its a wonder that it works at all. There is actually an end-user solution to this which involves using a tool called ndiswrapper to run the XP drivers inside Linux. But getting that working is another story…
Apt makes adding things to an Ubuntu install very easy. Almost too easy. Read the rest of this entry »
We have a fairly standard home networking setup – a DSL modem, a wireless router, and a hub distributing 100BaseT to some RJ-45 sockets scattered about the house. The modem and the router both have firewalls and web interfaces to them, but neither of them are very versatile. For example, one thing they can’t do is log traffic on a per-IP basis, so when we start using 500Mbytes/day they can’t tell me which machine in the house it is coming from. We have a bandwidth cap, above which our ISP chops us back to 64Kbits up and down, so that can be important. Nor can the DSL modem firewall send mail to me logging firewall rejects, so sometimes when something doesn’t work it can be difficult to tell whether its the PC, the firewall, or something broken in the outside world. A proper firewall can do all these things and a lot more, as I know from running an OpenBSD-based firewall for my employer for the last ten years. And the firewalls in DSL modems don’t have such a great reputation for security. Holes have been found in some. Our modem has an additional peculiarity; it insists on running a DNS cache and providing its own address as a DNS server to local machines. Unfortunately the cache isn’t all that great and falls over every two or three days. The only solution is to turn the modem off and on, which is a bit vexing.
So that was one reason to look at installing a separate stand-alone machine to act as a firewall. Read the rest of this entry »