Sometimes I have to check drives under their native operating system. Recently I wanted to access a ntfs partition directly under Windows running inside a virtual machine. Here’s how to (easily) do it:

#>VBoxManage internalcommands createrawvmdk -filename ./ntfs_test.vmdk -rawdisk /dev/sdb -register

VirtualBox Command Line Management Interface Version 1.5.4

(C) 2005-2007 innotek GmbH
All rights reserved.

RAW host disk access VMDK file ./ntfs_test.vmdk created successfully.

What this means? Well:

We create a virtual machine disk (vmdk) pointing to you physical drive. /dev/sdb in our case, be sure to point to yours. -register if set will tell VirtualBox to already register the drive inside your Virtual Media Manager.

DANGER: the disk will be fully available to the guest operating system. This means full access – so any command you use is definitive. Should you delete, partition or format the drive this will happen exactly as if you have booted the guest operating sytem directly.

I wanted to play a bit with the Mozilla Firefox 4.0 beta. Well, if you go to the download site there’s no apparent way to download the 64 bit version of Firefox. This is where I got it:

ftp://ftp.mozilla.org/pub/firefox/releases/4.0b1

God a fancy new drive? SSD maybe? TRIM support advertised?

Well, here’s how you can check if TRIM support is actually enabled and working in your windows installation:

Start a command prompt window (WIN+R, type cmd and press enter)

In the command prompt window type the following:

fsutil behavior query disabledeletenotify

You will get one of the following:

DisableDeleteNotify = 1 (Means that Windows TRIM commands are disabled)
DisableDeleteNotify = 0 (Means that Windows TRIM commands are enabled)

What is TRIM and why do you need it

In computing, a TRIM command allows an operating system to inform a solid-state drive (or “SSD”) which data blocks, such as those belonging to a deleted file or affected by a format command, are no longer considered in use and can be wiped internally.

TRIM was introduced soon after SSDs started to become an affordable alternative for traditional hard disks as permanent storage in PCs. Because low-level operation of SSDs differs significantly from traditional hard disks (see details below), the typical way in which operating systems handle operations like deletes and formats (not communicating the involved sectors/pages to the storage medium) resulted in unanticipated progressive performance degradation of write operations on SSDs. TRIM enables the SSD to handle garbage collection overhead, that would otherwise significantly slow down future write operations to the involved blocks, in advance.

[from wikipedia.org]

I recently found out that the power management inside the new I5 and I7 Intel processors is much more inteligent than what the older core2 has. For example a core2 would throtle back based on temperature only just before the critical point.

The newer I5s and I7s would turn cores on/off or independently slow down depending on load, power consumption and temperature.

Basicly this means that you might get less from your cpu if it runs hot – either because of the weather or because of inapropriate cooling,

Also overclockers should be careful. You might be happy that your machine is stable at the new speed but it coukd be that it’s only throttling down all the time.

Posted by Wordmobi

Let’s say you run a headless server and you want to fsck the main partition. The easy solution in this case is (if possible) to force fsck to run on the next boot.

If you run slackware than all you really need is to create an empty file in /etc called forcefsck

You could do this by running:

touch /etc/forcefsck

Other linux distributions might check for this file elsewhere, for example in the root directory so the command would be

touch /forcefsck

Checking the documentation will always help.

I recently had to set values of a set of values from a column from lowercase to Firstuppercase. Nothing easier, run the following code on the database:

UPDATE `affected_table` SET
`field_in_question` = CONCAT(UPPER(LEFT(`field_in_question`, 1)),
SUBSTRING(`field_in_question`, 2))

One of my clients called be mecause every now and then his was bugged by Windows XP to change his password. This seemed weird as XP doesn’t do this by default. Probably it was set to expire by someone or by some friendly security suite.

Fortunately the solution for this expiring password problem is easy. You just need to tell Windows that you want your password to never expire. This is not necessarily a good practice, nevertheless if you want to, here is how you do it.

• Go to START->RUN or WIN+R.
• Type control userpasswords2 and hit ENTER

You’ll get a window like this one showing up:

• You have to click the Advanced tab

• Unsurprisingly, on the Advanced tab you have to click the Advanced button. (Who designs this kind of interfaces?)

• In the window that opens you can see your local users and groups.
• Click on Users and double click in the right panel the user you want to set the password not to expire.

• Finally in the new window that opens check Password never expires.
• Apply or OK your way back!

Done. Still it’s a good ideea to change all your passwords from time to time, just to be on the safe side.

Like I said some time ago I had to move my websites from a shared host (bluehost) to a dedicated sollution. Well, the websites I host (for clients, friends and myself) don’t account for the need of a dedicated server so I searched for a virtual sollution.

I finally came to the conclusion that unmanaged is the way for me. I’m working on the old premise “give me a machine, an IP, a net pipe and some power” and I’ll manage from there.

Finally after some research I was left with two: Slicehost and Linode. From the features listed and user testimonials I found on various forums they are equally good. Simply when I needed to sign up Linode offered more space and RAM for the same amount of money, so the choice was easy.

What I like:

• recently awarded more RAM as a 7 year Linode anniversary.
• broad choice of operating systems
• root access including console (if you borke your ssh daemon you can still login)
• disk image tools
• custom warnings on cpu, memory and bandwith  increasing over certain limits you get to define(not that you are penalised but it simply means you probabbly have something hanging)
• you can choose the datacenter and move your machine from one to another
• you can easily buy more resources (ram, disk, bandwith)
• It was never down for me
• DNS manager
• Statistics and everything

What I don’t like:

• no symbian application or mobile admin website (only iphone and maybe android) – not a big deal, I still have an ssh client on my phone and the regular website works decent on my nokia’s browser

So, if you’re in the market for a virtual host I can recommend Linode from all my heart.

I have some albums that were ripped in wma form (yes a shame I know). I wanted them converted into mp3 so my collection remains consistent.

So this would be a command to run in a folder filled with .wma files. This keeps the names but not the tags so be sure to use something like easytag to fill them after.

for i in *.wma ; do mplayer -vo null -vc dummy -af resample=44100 -ao pcm:waveheader "$i" && lame -m j -h --vbr-new -b 320 audiodump.wav -o "`basename "$i" .wma`.mp3"; done; rm -f audiodump.wav

If you, like many of my clients regularly receive files from partners that have already upgraded to microsoft office 2007 have the annoyance that the files are always saved in the docx format (because people don’t go to the trouble to Save as office 2003) then you probably think that it’s time to upgrade. Right? Wrong! There is an easier sollution – not to mention a lot cheaper. Go to the microsoft website and download the

Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats

This pack will allow your existing Office 2003 installation to open files in the newer formats. Problem solved !

Well there is another sollution, but this one is a bit more complicated but better on the long run. Just migrate to Open Office! It’s free, it’s open and can read the new formats introduced by Office 2007.