Installation

Surprise! If you are using a modern Ubuntu distribution you should find Baobab pre-installed and located in Applications > Accessories > Disk Usage Analyzer. If you do not find it installed on your machine, you will find it in your standard repository, so just follow these steps:

1. Open up Ubuntu Software Center.
2. Search for “baobab” (No quotes).
3. Click Install.
4. Let the installation finish.

Features

• Scan entire file system.
• Scan specific directories.
• Scan remote server.
• View as Ring Chart or Treemap.

Usage

Figure 1

When you fire up Baobab you can immediately initiate a scan by clicking the button associated with the scan you want to run (see Figure 1). If you want to just scan your ~/ (HOME) directory click the Scan Home button. To scan the entire file system click the disk button (second button from left).

Figure 1 shows the results of a full file system scan displaying in a Ring Chart view. If you hover your cursor over a specific ring the details of that ring will appear (really, it only gives you the location associated with that ring). If you hover your cursor over the center circle you will see the details of each ring.

Figure 2

But let’s say you want to take a peek at a specific directory on that file system. To do this you can navigate to that directory in the left pane and then select the specific directory you want to view. Figure 2 illustrates the details shown when you hover your mouse over the center circle.

Instead of navigating from the left pane, you can also navigate your file system hierarchy by clicking on the various rings. When you click on a ring you will dive deeper into that ring to reveal sub folders. Once you have reached the deepest child directory the only graphic displayed will be the gray circle.

Scanning a remote folder

To scan a remote folder you click the remote folder button (the up and down arrows) and then walk through a wizard that should be familiar (It’s the same wizard you use in GNOME to connect to a server from within the Places menu). Once connected, the scanning process is exactly the same as it is when you run a local scan.

Final thoughts

If you are looking for a tool to help you keep track of how your file systems are filling up, Baobab is an outstanding tool to fill this need. It’s simple to use, flexible, interactive, and works well locally and remotely.

Bleachbit easily clears out free space, removes junk, and helps to guard your privacy. Bleachbit goes beyond just deleting files. You can set this tool up to shred your files as well…so when they are gone, they are really GONE! It’s not just for Linux though. Bleachbit is available for Windows as well – and both versions are open source. In this article I will show you how to install and use Bleachbit.

Installation

Installing Bleachbit is simple. Go to the download page and download the version that is right for your distribution.  There are binary files available for Ubuntu, Fedora, CentOS, Mandriva, Debian, OpenSuSE, RHEL, and SLED. Let’s take a look at installing in either a Ubuntu or Debian environment. The file you will download will be a .deb package. Save that file to familiar directory and follow these steps:

1. Open up a terminal window.
2. Change to the directory where the Bleachbit binary is stored.
3. Issue the command sudo dpkg -i bleachbit-XXX.deb Where XXX is the release number.

That’s it. Bleachbit is now installed.

Usage

Figure 1

When you first fire up Bleachbit the Preferences window will open up along with the main window (see Figure 1). As you can see there are three tabs to configure:

General: If you are really concerned about privacy you can check the box for Overwrite files to hide contents. What this will do is overwrite deleted files so their contents can not be viewed.

Drives: Add a drive (directory) to be included in the overwriting of free space.

Languages: All languages will be deleted except for those checked.

Figure 2

Now let’s take a look at the main window. Bleachbit is really quite simple to use. Scroll down to the section you want to set up (see Figure 2), make your selections, and click either Preview (to see what will be done) or Delete (to run the actions).

You may notice, depending upon the sections you mark, that you will get either information or warnings. For example, in the System section if you click Memory you will be warned that this section is experimental and it could cause system problems. If you’re working on a production machine you might want to avoid selection this option. Another warning you might see is the Free Disk Space will alert you that the option is slow. So if you’re going to opt to clean the free disk space (this is overwriting deleted files) your system might become a bit sluggish or the cleaning might take more time than expected.

Once you have made your selections click Preview which will then give you a report detailing all of the files it will delete. If you’re happy with the report, click Delete and Bleachbit will do it’s business.

Final thoughts

If used with caution, Bleachbit will keep your system free of junk and your deleted files free from prying eyes. Just make sure you do use this with caution – especially on production machines, where data loss is tantamount to you losing your sanity or your job.

The way Microsoft has implemented file compression in the operating system makes it difficulty to manage. That’s where the free software NTFS Ratio steps in.

NTFS Ratio can be used to analyse a folder structure on a hard drive that has been formatted with the NTFS file system. The program displays all files and folders in that structure as well as their compression status and ratio. The application will also display total stats for all files and folder in the file structure.

The list can be printed or copied to the clipboard. The reporting feature can be interesting for users who want to analyse the file compression on their computer system, especially its effectiveness. A right-click on a folder or file provides a Windows Explorer like context menu with options to compress and decompress folders.

The results of these actions are directly displayed in the program’s interface. NTFS Ratio is a niche software for users who use NTFS file compression. The program is compatible with most Windows operating systems including Windows 7. It can be downloaded from the developer’s website (German but should not pose a problem for non-German speakers).

The main advantages of exFAT in comparison to FAT32 are the removal of the 4 GB file size limit and support for hard drives with large capacities (recommended maximum sizes for both are 512 TB). The exFAT file system driver will add the option to format removable media with the exFAT file system to take advantage of it. The file system is using a smaller disk space overhead than the NTFS file system. Users reported a disk space overhead of only 96 Kilobytes on a 4 Gigabyte flash drive after formattting it with the exFAT file system. The NTFS file system used more than 47 Megabytes of space for overhead.

Interested users can download the exFAT file system driver update directly from Microsoft to add exFAT file system support to their operating system.

The exFAT file system driver incorporates the following advanced structures to improve performance:

* A cluster bitmap for fast allocation
* A per-file contiguous bit for fast file access
* Better contiguous on-disk layout (useful for recording movies)
* Support for Universal Coordinated Time (UTC) time stamps

The exFAT file system driver is designed for extensibility to enable the file system to keep pace with innovations in storage and changes in usage and to enable OEMs and ISVs to add extensions seamlessly. Specifically, exFAT adds the following features:

* Adds template-based metadata structures to enable custom extensions
* Enables implementations to persist these extensions without having to know their format

The exFAT file system driver adds increased compatibility with flash media. This includes the following capabilities:

* Alignment of file system metadata on optimal write boundaries of the device
* Alignment of the cluster heap on optimal write boundaries of the device

The prerequisites for the update are an installation of Windows XP Service Pack 2 or Service Pack 3.

What fstab does

As said earlier, the /etc/fstab file is a means to map devices to locations so the devices can be used. Typically when you plug in an external device that device will show up as a device in the special directory /dev. Most externally connected usb devices will show up as a variation of /dev/sda. But if you try to access that device through the /dev directory you’ll have no luck. Instead you have to map the device to a regular, mountable directory so the device can be used. Without the fstab file only the root user would be able to do the mounting and the mount command would always be something like “mount /dev/sda2 /media/mp3″. When the root user mounts a device in this way only the root user will have write access to the device. In the case of an mp3 player that means only the root user will be able to add music to the device. That’s where fstab helps out. You can create an fstab entry that will allow standard users to mount and unmount devices as well as write to those mounted devices.

Typical fstab entry

The structure of an fstab entry is:

device   mounting_directory      filesystem_type     options    0 0

The device will always be assigned once you have plugged in what it is you are going to mount. The easiest way to find out what has been assigned is to open up a command terminal and enter the command dmesg. Using dmesg will require you to keep issuing the command until the kernel has recognized the device. Or you could enter the command tail -f /var/log/messages (must be run as root). Using the tail command will keep follow the output of the messages log file which will give you all the information you need.

With the understanding of where you get the device location in hand let’s move on to the mounting_directory entry. This is quite simple: Create a directory, as a sub directory under /media named after the device you want to mount. For instance, if you are going to mount a USB thumbdrive you can create a directory called /media/thumb or if you need to mount your iPod you can create a directory called /media/ipod. This directory is where you will be mounting your device. When the device is mounted there you will go to that directory to manage the devices’ data.

The next section, filesystem_type, describes the type of file system you wanting to mount. Linux supports quite a large selection of file systems such as: cramfs, efs, ext2, ext3, vfat, fat, nfs, udf, sysv, smbfs, minix, msdos, reiserfs, hpfs, hfs, iso9660, and many more.  There is also the auto file system type which means the kernel will discover the type.

The options section of fstab is where things start to grow a bit more complex. I will explain the more common options:

• auto/noauto: The auto option is default and means the device will be mounted automatically. The noauto options means the device will not be mounted automatically. By “automatically” I mean either at boot or when the command mount -a is issued.
• user/nouser: The user option allows all standard (and root) users to mount the device. The nouser options only allows the root user to mount the device.
• ro: Mount the device in read only mode.
• rw: Mount the device in read/write mode.
• sync/async: The sync options writes data to the device on the fly (as soon as a command is issued) whereas the async option writes data later.
• suid: This allos suid and sgid bits to be effective on the mounted file system.
• defaults: Use all default options (rw, suid, dev, exec, auto, nouser, and async)

The final section is actually the dump/fsck section. Basically if you set these bits to 0 (off) the mounted devices will not be checked by either dump or fsck. You will rarely, if ever, need anything but zeros here.

Final Thoughts

So there it is. The basics of the oft-confusing fstab file. Later we will get into some sticker fstab issues, but for now you should have a pretty sound understanding of how fstab works.

Basically anything can be added to an existing file (and directory) which brings up an interesting method of hiding important data on the system. Say you want to keep your passwords on the computer but do not want to use a text document to have them in the open. Using Alternate Data Streams to hide them from prying eyes could be a relative secure method of storing the password list on the computer.

They are detectable if the right software is being used. Windows Vista users can also use the dir *.txt /R which is further explained at Bart De Smet’s on-line blog.

To add textual information to any file in Windows you could use the command notepad filename:name for example notepad image.jpg:secret. This would open up Notepad and a blank text file at the first run. Any text that is added and saved during that session will the shown if the user opens the text document with the same command at a later time.

Executable files or other binary files can be added with the type command like this: type c:\text.exe > hello.txt:text.exe which can be executed with the start command start .\hello.txt:text.exe.

If it states Fat32 you should consider changing this to NTFS. Let me explain why it might be advantageous to do that. Generally speaking one could say that NTFS improves performance, reliability (Fat32 are more susceptible to disk errors), security and disk space usage if you have been using FAT32 file systems previously.

There are some exceptions to this rule which should be noted here. First, if the size of your hard drive is below 8 Gigabytes Fat32 might be the better choice disk space wise. It is definitely the better choice if you have a dual boot system with an older Microsoft operating system such as Windows 98.

It is possible to convert a FAT32 to NTFS without data loss. I would still advise to make backups of the important data before starting the conversion in case something goes wrong. (Power failure anyone ?) Please note that this is a one way process, you can’t convert the file system back to FAT32 easily.

Press Windows R, write cmd and hit enter. You only need to write down one command: convert c: /fs:ntfs where c: is the drive that you want to convert. Just change c to whatever drive you want to convert. The conversion will start after rebooting the machine. All data on that drive will still be available after the conversion from FAT32 to NTFS.