Saturday, November 29, 2008

Mounting usb-drives with a NTFS lock on it.

Everybody has come across it, your in a hurry and unplug the usb drive before Windows releases the disk. This is how to solve it when you have a linux (or a bootable linux cd) machine.

First you make a directory on which you will mount the disk. For people new to linux this is just a simple directory to which you will attach the disk.

Open yourself a shell prompt and type the following:
mkdir ~/mydisk

This will make your directory in your home directory.

The type the following:
mount -t ntfs-3g /dev/sdg1 ~/mydisk -o force

This will mount the disk presented at the device /dev/sdg1 and attach it to the folder ~/mydisk. For people new to linux I recommend to do some further reading about devices.

My system answers me with :
$LogFile indicates unclean shutdown (0, 0)
WARNING: Forced mount, reset $LogFile.

And I find the disk mounted under ~/mydisk

FOSDEM 2009 and HAR2009

I want to tell you about 2 upcoming events: fosdem and HAR2009.

Fosdem is according to their website a free and non-commercial event organized by the community, for the community. Its goal is to provide Free and Open Source developers a place to meet. (http://www.fosdem.org/2009/). Fosdem will take place the 7th and 8th of February 2009 in Brussels. There are every year people comming from all over the world. One of the things I like is the open idea. If you want to talk to somebody and exchange ideas, you just walk up to that person and start a conversation. If you go back to the previous years you'll see that they managed to get some important speakers in the open source community.

HAR is totally something else. HAR's website is http://har2009.org/. It is an international technology & security conference. It will take place in August 2009 from the 13th till 16th near Vierhouten, NL. It is something like Rock Wechter but for people who are into technology and security.

I plan to go to fosdem to a couple of talks and I would like to go to HAR if it is possible.

Enter at own risk ... don't go eat there!

This week when I went to a customer with my colleague and we went out for lunch. Since we were in the Matongé area (a part of Brussels where a lot of African people live) we went to an exotic restaurant.

The name of the place is KAZI Surprise and it is located at the Chaussée de Wavre 46 in 1050 Brussels. We asked what the day special was it was goat with saka-saka or tilapia (fish) with fried bananas. We ordered the fish.

The fish had an odd tasted, clearly it was not fresh. Everybody knows that all fresh fish has a taste that is distinguishable from the not so fresh one.

Luckely in the hours that followed the experience my colleague and me didn't get the signs of food poison (although our stomachs were making some noises). I spoke to a doctor that evening and he told me that you would see the effect of food poisoning within the 4 hours.

I filed a complaint at the Federal Agency for Food Safety.

So my dear blog readers, don't go out to eat there.

Database mirroring on SQL 2005 SP2

Howdy folks,

This week I went together with a colleague to a customer where there were some troubles with the database mirroring on SQL 2005. It a high available mirror and the problem was it didn't work 100% of the time. Some times something like a split brain occurs. The database is recovering as well on the mirror as on the principal.

The thing we noticed was in the mirroring monitor that the server who had the principal role didn't have a successful connection to the witness server.

First thing we checked was the network. The situation goes as follows. The servers are in workgroup mode and there is a dedicated Gigabit connection between those server to sent the transactions to both servers. All servers were also defined in the host file so even when the DNS goes down it should work.

After crusing down the Internet I found a post in a forum of somebody with the same problem. The problem was solved for this guy by rebooting the system. So we restarted the SQL service of the witness server and it worked.

So that needed some further investigation. We created a new database, made it mirror and the same scenario ... no witness on the principal, only for that database. We restarted the SQL service on the witness and it worked :-)

Then we did the ultimate test, we stopped the endpoint on the server for which the server was mirror for the databases in production and principal for our test database. (So there was no impact for production). First time we tested it, everything went fine and the test database failed over (and we wrote a record in it). The second time we tried it, it failed and a split brain like situation occured. Okay, there was no problem to bring the test database online and since it is in sync mode no transaction could have been written to one side and not to the other.

The odd thing is that the production server had to be turned off that evening and the automatic fail over worked without any problems.

So some further investigations will be required. Currently we are thinking in the direction of cummulative updates. When we find it I'll make a post about it.

Monday, November 24, 2008

Converting a disk from FAT32 to NTFS

Today I had to convert my external disk form FAT32 to NTFS. I was confronted with the problem that an ISO file was 9GB and FAT32 couldn't handle that.


Convert is a tool that is part of your Windows OS.


Here is the syntax to convert the disk:

>convert diskletter: /fs:NTFS [enter]


After starting the convert tool you'll have to enter the disk label and the conversion starts. First it checks the disk for errors and than the actual conversion starts.