Change the front disc brake pads on the VFR

Changing the front brakes pads on the VFR is an easy task which should not take more than a copule of minutes.

First locate the front brakes, which should hopefully be fairly obvious. Once you are situated, remove the rubber cap and unscrew the pad pin. Be sure to catch the brake pads when you pull the pin out, or they may damage the rims. A towel or something similar beneath could be a life-saver if you happen to drop one of the pads.

Once the brake pads are removed, just remove the metal clip on the back and attach it to the new ones before installing them.

To easier set the new pads, be sure to push in the pistons without damaging them. There is not much else to it. Just remember to pump on the brake until you have pressure back.

I am not going to write about how to break in the brakes properly, since there are lots of different schools. Be sure to do this in some form however, or the pad surface may become glazed.

Enable 1Password in Safari 4 beta

Apple just released a beta version of Safari 4 with lots of new features. Users of 1Password might notice that it doesn’t work in the new version. To fix this, close Safari and 1Password and edit the following file:

/Applications/1Password.app/Contents/Resources/SupportedBrowsers.plist

Find the Key named Safari and look for MaxBundleVersion underneath. You will see 5528.1 as the maximum version. Change that to 5528.16, save and quit. Now you can reenable Safari from the 1Password preferences and then start Safari 4 and add the button to the toolbar. Voila!

How to cancel your Audible.com subscription

I recently got the offer to try out Audible. They have a huge library with audiobooks of all kinds with great quality and an enjoyable experience. That is until you want to cancel your account.

At the beginning, there is in fact a cancel link available, which of course makes users feel at ease with the service. After a while however, the link disappears and cancelling the account becomes practically impossible without spending an enormous amount of time on the phone talking to the customer support. I did email the customer support about this a while ago, but still haven’t received a response.

I really liked their audiobook service but after pulling this stunt, I just can’t stick around anymore until they remove this redicilous “feature”.

So, you might ask: Is there an easy way to cancel my account? Yes, there is! Just make sure that you are logged in to your Audible account and then click the following link, answer some questions, and presto!

Cancel Audible account

Automate system administration tasks using Nagios

As a system administrator, one often have to do repetitive tasks such as checking for free disk space, check mail queues and monitor critical services. If there are only a handful of servers, this task may not be very intimidating, but there are many times when there are many servers to monitor, or just for the sake of automation. This is where Nagios comes in.

Nagios is a host and service monitor designed to inform you of network problems before your clients, end-users or managers do.

This is exactly what we need to make an automated system for monitoring! I will not go into details on how to set this up, since there is an excellent quick start guide available on the website. Instead I will focus on how Nagios has eased the burden of managing a large number of servers.

I have ready made templates for servers and when a new server is added, I just create a copy of the template and add or remove the services needed to monitor the server.

Public services are easy to monitor directly from Nagios, but private data such as disk space and CPU load demands a local service running on each of the servers. This is where NRPE comes into play. NRPE is a daemon which listens on the network and will respond to Nagios queries, using standard Nagios plugins. In Debian and Ubuntu, just install the nagios-nrpe-server package, and in Windows NSClient is very usable and easy to configure.

The last thing is alerts management. All servers that someone else manages, or is in charge of, should receive the Nagios alerts for that server. It will dramatically lighten the administration burden if it is possible to delegate as much as the server / service responsibility to other people. For extremely critical services, there should be an SMS gateway, which sends a message to the administrator or someone in charge of the server. This ensures that attention is immediately brought to the problem.

Create a fixed size network storage for Time Machine

Time Machine is a backup program built into Mac OS 10.5, Leopard. It saves all files on the computer on a USB  or network drive, which can be used for restoration of individual files or the whole computer.

The normal behavior of Time Machine is to keep

  • hourly backups for the past 24 hours
  • daily backups for the past month
  • weekly backups until your backup disk is full

It is the last point that might cause some trouble for some people, since many people might share the drive with other type of data. There has to be some way to limit the size of the backup volume. This is my approach.

Preparing an image

The first step is to create an image to hold the backup filesystem. If you want this filesystem encrypted, have a look at Mounting encrypted volumes, otherwise just follow the following steps. The image will be created as /ext/timemeachine.img and it will be mounted in /ext/timemachine.mnt.

dd if=/dev/zero of=/ext/timemachine.bin bs=1G seek=250 count=1
losetup /dev/loop1 /ext/timemachine.bin
mkfs.ext3 /dev/loop1
tune2fs -c0 -i0 /dev/loop1
losetup -d /dev/loop1
mkdir /ext/timemachine.mnt

The first thing is to create an image file, and using the dd command we create an empty 250GB file, which will contain the backups. The next step is to setup the image as a loop device, which makes it possible to mount it as usual. loop1 is currently used, but if you know that it is occupied, feel free to choose another device.

The next step is to edit /etc/fstab and add a line which will automatically mount the filesystem when the computer boots.

/ext/timemachine.bin /ext/timemachine.mnt ext3 loop=/dev/loop1 0 0

Then we will mount all filesystems and verify that it has indeed been mounted.

df -h
/ext/timemachine.bin  248G  188M  235G   1% /ext/timemachine.mnt

There should be a line like the above if everything is working correctly. The last step is to set the correct permissions for the directory for your user.

chown -R joch /ext/timemachine.mnt/

Setting up the Samba share

To connect to the server, it is necessary to setup the Samba server. Create a share like the following in /etc/samba/smb.conf.

[tmbup]
comment = Time machine backups
path = /ext/timemachine.mnt
browseable = yes
read only = No
inherit permissions = no
guest ok = no
printable = no

Now just reload Samba and add a user if you have not done so before.

invoke-rc.d samba reload
smbpasswd -a joch

Setting up Time Machine

Connect to the share in Finder as usual.

Finder window

Open up the Time Machine preferences and click Change Disk. It should give you a dialog like this, and Time Machine should then be enabled.

Time Machine setupTime Machine enabled

If you get the error “Time Machine Error: The backup disk image could not be created.”, you will need to do some magic on the server.

Time Machine error

You need to start the backup once again, but this time you will have to be quick and copy the directory it creates on the server. Once Time Machine has finished, the original directory will be deleted, so just copy the saved directory back to the same place.

cp -rp Johnnys\ MacBook\ Pro_001ec2123456.sparsebundle/ ..
# Wait until Time Machine has finished
cp -rp Johnnys\ MacBook\ Pro_001ec2123456.sparsebundle/ timemachine.mnt/

Now run the backup again, and it should complete successfully!

Time Machine run

This behaviour is very strange, but the above trick always solves the problem.

Merge your Google talk and MSN Messenger accounts

If you are using Google Chat or any Jabber account, you have probably noticed that you can connect to the same account from multiple places simultaneously. Now image that you could do the same with MSN Messenger – well now you can!

Use Gajim or another Jabber client with transport support and just add an MSN transport at a Jabber server. Just use a public Jabber server with support for MSN transports if you don’t have your own.

Gajim transports

Just select the MSN transport and enter your username and password, and your Messenger contact list should start entering the Jabber list. If you now look at the chat in Gmail or another Jabber client such as iChat, all your contacts should be there.

There are some downsides to this setup though. User pictures are not always updated as they should, as well as set usernames.

Run virtual servers using XEN

Running virtual servers may save you a bundle on server costs, but in the same time create a more secure environment by separating services into logical hosts. This guide will show you how to setup a XEN virtual server using Debian, but it may also be used on Ubuntu if that it preferred.

Installation

The first task is to install all required software packages. Installing the virtual xen package will in turn install all required programs like a new libc6, kernel with virtual support and the xen hypervisor. Installing xen-tools makes it very easy to create new virtual servers.

# aptitude install xen-linux-system-2.6.18-6-xen-vserver-686 xen-tools

After installing the new kernel and libs, you will need to reboot the computer to use it.

Configuration

The virtual hosts need some way to access the network, so we have to create a network bridge for them to use. Open the file /etc/network/interfaces and create a section like the following. Be sure to change the network settings to reflect your own network.

iface xenbr0 inet static
address 10.10.10.100
netmask 255.255.255.0
network 10.10.10.0
broadcast 10.10.10.255
gateway 10.10.10.1
bridge_ports eth0

Open up the xen configuration file /etc/xen/xend-config.sxp in your favorite editor and make the following changes.

(network-script network-bridge)
(vif-script vif-bridge)
(dom0-min-mem 196)
(dom0-cpus 0)

The configuration file contains lots of comments, so I will not go into detail about every change.

The last configuration is for the xen-tools package /etc/xen-tools/xen-tools.conf, which we will use to create the virtual machines. Be sure to change the network settings and home directory to match your envionment.

dir = /home/xen
dist   = etch
gateway   = 10.10.10.1
netmask   = 255.255.255.0
cache = no
passwd = 1
mirror = http://ftp.se.debian.org/debian/

The rest of the values can probably be left alone, but do take a look at them to see if you need to custmize anything.

Now to create a new virtual host, just write the following and debootstrap should start installing a fresh Debian system.

xen-create-image –ip=10.10.10.101 –hostname=host1.chadda.se

When the installation part is finished, just start the host (or create in xen speak), using the following command.

xm create /home/xen/domains/host1.chadda.se/host1.chadda.se.cfg

If you add the -c option, you will attach to the virtual console and you will see all output from the guest.

Enjoy

Now enjoy your new virtualized server!

How I get things done on the Mac

Having moved from a Linux desktop to a Mac, I have been forced to find new applications to help me read email, manage tasks and projects, take notes very easily and everything else work related. After investigating the options, I have found some applications which does their job very well. Read on to find out which applications are on the top of the game.

Email

For reading email, I now use the built-in Apple Mail client. It does its job very well indeed, but it does lack some features. It is for instance not possible to use client certificates for IMAP and SMTP yet for some strange reason, but it was a breeze setting upp stunnel to listen for unencrypted connections on localhost, and forward these to the mail server, encrypted using my client certificate.

I also have problems with my todos, especially when trying to attach them to email messages. The following message appears in the log:

WebKit discarded an uncaught exception in the webView:didFinishLoadForFrame: delegate: trying to set a non-ToDo MailboxUid for a ToDo. The MailboxUid for a ToDo must be a ToDosMailboxUid

Hopefully Apple will have a solution to this problem soon.

For some pointers on how to keep the mailbox sorted out, have a look at 43 Folder’s Inbox Zero series, or one of the many Lifehacker posts.

Taking notes

Even though it is quite possible to store notes in Apple Mail, there is definitely a use for a more powerful application such as Evernote. If you are a Lifehacker reader, you will probably have it downloaded for free. With it, it is possible to take notes on just about anything, and if there is something interesting on a website, it is just a matter of selecting the text and select “Paste to Evernote” in the menu. Brilliant!

evernote.png evernote-attributes.png evernote-menu.png

Evernote has a built-in syncing facility, which makes it possible to browse all notes directly on the web from any computer! There is also a Windows client, but I have not had the chance to try that one out.

Managing tasks

To manage tasks, the popular Things is the perfect choice. Although it is just a beta, it does what it’s supposed to do – and it does it very well! It also seems to match up well with other popular project management applications. For instance, read the iGTD2 vs Inbox vs OmniFocus vs Things comparison (Thanks Maria).

I fell head-over-heels in love with this application. Right from visiting the excellent website and then firing up the application for the first time, I knew Things was something special.

A pictures says more than a thousand words, so here is one (but with the words censored out though).

things.png

It displays the task in true GTD style, which will hopefully make it fairly easy to actually manage everything. For a more in-depth introduction, have a look at the screencast on the Things website.

Calendar

Most people would assume that using iCal would be the optimal choice. Perhaps. But most people I work with are using Google Calendar, which basically forces me to use it as well. There are some tools such as Spanning Sync for syncing iCal with Google calendar, but they all seem to have some problems. It works very well syncing to the phone using GooSync and subscribing to it in iCal.

I am quite happy with this setup, and it seems to be working really well. The only thing I can complain about is that Evernote does not save all formatting from websites, like for instance Apple Mail does with its notes feature. Not a big issue of course, since the text iself often is the important part, but still an annoyance.

Using SIP with the Nokia E61i and Gizmo

I usually have no use for a normal landline, but it does have its benefits. Since I will be moving to a new place soon with a 100/100 Mbit Internet connection, why not use it to the max? So I am trying SIP with my phone using Gizmo and their SIP service.

Setting things up could be a bit confusing, but the following settings works fine for me (for Gizmo):

  • Profile name: Gizmo
  • Service profile: IETF
  • Default access point: “my access point”
  • Public user name: sip:[email protected]
  • Use compression: No
  • Registration: Always on
  • Use security: No
  • Proxy server: Do not fill in anything here
  • Registrar server address: sip:proxy01.sipphone.com
  • Realm: proxy01.sipphone.com
  • User name: 17472xxxxx
  • Password: “your password”
  • Transport type: UDP
  • Port: 5060

Now when ever I stumble upon an access point I have configured, the phone will connect the SIP phone automatically! The call quality seems to be really good after a first try, but we will see if it holds up.

Nokia has really managed to get a good SIP phone working in a simple yet effective way, and it is even possible to decide whether the calls should be routed over SIP by default or not.

I could definitely see this working in a corporate setting with an Asterisk server for VOIP and WLAN for connecting the phones to the networks. It is even possible to store a SIP number in the phone book for each contact, which makes this solution ideal.

Speed up your Synaptics touchpad in Ubuntu

The synaptics touchpad found in many Dell machines and others is extremely slow in the default Ubuntu installation. Manipulating the mouse settings in the preferences doesn’t help either, so what to do? Using it when this slow becomes really frustrating in the long run.

Luckily I came across a post by aboe on the Ubuntu forums, which suggested some additional options in the synaptics section of xorg.conf. After trying this out, the touchpad immediately felt snappier and is finally useful!

I have copied the configuration here for reference, if the original post ever disappears.

Section “InputDevice”
Identifier “Synaptics Touchpad”
Driver “synaptics”
Option “AlwaysCore”
Option “SendCoreEvents” “true”
Option “Device” “/dev/psaux”
Option “Protocol” “auto-dev”
Option “LeftEdge” “130”
Option “RightEdge” “840”
Option “TopEdge” “130”
Option “BottomEdge” “640”
Option “FingerLow” “7”
Option “FingerHigh” “8”
Option “MaxTapTime” “180”
Option “MaxTapMove” “110”
Option “ClickTime” “0”
Option “EmulateMidButtonTime” “75”
Option “VertScrollDelta” “20”
Option “HorizScrollDelta” “20”
Option “MinSpeed” “0.60”
Option “MaxSpeed” “1.10”
Option “AccelFactor” “0.030”
Option “EdgeMotionMinSpeed” “200”
Option “EdgeMotionMaxSpeed” “200”
Option “UpDownScrolling” “1”
Option “CircularScrolling” “1”
Option “CircScrollDelta” “0.1”
Option “CircScrollTrigger” “2”
Option “SHMConfig” “on”
Option “Emulate3Buttons” “on”
EndSection

Yes I know, the quotes are converted by WordPress. Sorry about that.