Electronic Design

Carrying A Corsair: A Trip With A Memory Stick

It seemed like a good idea at the time: Hit the road with Corsair’s 16-Gbyte Voyager flash memory drive (Fig. 1); load up a bootable copy of Linux; find a machine and plug it in. The results, however, were mixed.

Essentially there are four ways to provide a mobile environment short of a laptop. The first is to boot an operating system and environment from an external device like a USB flash memory stick. The second method is to run an operating system from the device that works in conjunction with the host environment, typically a Windows PC. The third option runs the applications from the removable media. Finally, it may be possible to install a new operating system (OS) or applications from the memory stick.

The growing USB flash memory stick capacity continues to grow and has certainly past the size where it is easy to install a full copy of Linux complete with applications. The same could be said for Windows except that the last version of Windows 2000 was the last version of the OS that this could even be attempted. Since then, Windows has been tied to the hardware and not easily moved from machine to machine and that was the purpose of this exercise.

As with an external hard disk, it is possible to partition the flash drive into four partitions. I started by installing a 32-bit version of Ubuntu, a Linux distribution in the first partition and a DOS partition as the second. The latter allows data to be exchanged with most operating systems including Windows and Apple’s Mac.

I decided to drop a 64-bit version of Ubuntu in the third partition along with a version of Xen, a virtual machine manager. The latter will allow multiple operating systems to be run including Windows. Ubuntu installs the grub boot loader that can handle multiple operating system copies.

I won’t go into the details of installing Ubuntu on a flash drive. There are plenty of “How To’s” online. The chore is significantly easier with a large flash drive since it is essentially a standard installation. In fact, the hard part is typically making sure that content is installed properly on the flash drive.

The Quirks, The Kinks
If everything works properly, it is just a matter of plugging the Voyager into a PC and rebooting the PC. Unfortunately, there are a number of problems that can arise. For instance, older machines do not support booting from a USB 2.0 flash drive. Also, some systems are configured to boot only from the hard drive—or at least not from the USB port. Fortunately, my system did boot up Ubuntu and I had access to all the applications I normally use.

Another big problem I run into on many systems deals with network access. With wireless networks, I often had to get the SSID and passwords to access the system—assuming I have the proper wireless adapter driver—which tends to be the major problem. Ethernet adapters have been known to put up a fight as well, but there tends to be less variance there. Finally, in some instances the network adapter’s IP and/or MAC address had to be replicated. That’s not too hard to do for experts like myself, but probably a royal pain for anyone else.

Overall, booting Ubuntu from a memory stick works occasionally simply because of the variety of machines available. Newer machines, especially laptops, tend to work well (assuming the network administrator has not locked down the system). This is often the case when trying to use computers found in hotels, trade shows, or other public venues. Likewise, better organizations at least restrict non-employees from doing this with company systems.

Sharing The Hardware
Another alternative to using your own environment is to install it on another PC. This does not work well if the PC is locked down, but in many cases you may have a PC that you own or control and want to have an environment that is your own. In this case, our 16-Gbyte Voyager comes in quite handy since it has enough space to contain the operating system installation program.

There are at least two Linux platforms that work with Windows. These are Colinux and Topologi Linux. They essentially hook Linux device drivers into Windows so Linux is running atop Windows. The installation process is essentially the same as installing an application, but administrative rights will be required making this a non-starter on many machines.

The advantage is the ability to configure the Linux environment to your needs. I find this useful on machines that I will be using often but where dual booting is not a desirable option. It also works better with machines where novices will be using the existing applications since the Linux environment will not be running by default.

Going Virtual
Virtual machines are one of the best alternatives since the virtual machine image can be contained on the flash drive. It is also possible to keep the VM installation software on the flash drive but, like the prior option, installation requires administrative rights. The downside is that appropriate hardware and software is needed. This is where cost can come into play. There are a couple VM options such as those from VMware that are reasonably priced or even free in some cases. Likewise, Linux hosts can run VM platforms like KVM and Xen.

Like the dual boot systems, the VM approach can stay out of the way of normal users while providing an execution platform for advanced users. Installation of the VM software can be a small challenge but once in place it is a relatively trivial exercise to run another operating system. The number of client operating systems depends upon the performance and capabilities of the host and the needs of the user. Some systems can run a range of operating systems including ones like Microsoft Windows XP. This can be done regardless of the host platform since the client operating system is linked to the virtual machine, not the physical machine. Check your licensing because your liability may vary. For example, Windows Vista Ultimate is often the choice for a client where as the Home version is not.

Just The Mail
A less intrusive approach forgoes a new OS and simply runs applications on the host. This used to be the conventional approach, especially when configuration files were the norm and licensing was often less restrictive. The current problem is with most Windows applications that now use the Windows registry to store information as well as requiring various runtime modules to be installed on the host machine. This is easy with a dedicated machine but a royal pain if the application is to move with an external device.

Luckily there are many applications, often open course, that can run from a flash memory disk without any or minimal interaction with the Windows registry, etc. For example, Mozilla Thunderbird, an open source email program, can be configured to run off a memory stick. It is not the default configuration but there are enough instructions online to make this a relatively easy option.

Unfortunately, this approach to application mobility can be a challenge since not every application will perform in this fashion and there is not always a support group or company that can provide this type of support. Still, in many cases, mobile users require only a small number of applications and can take time to get them to work. As with OS installation, it is possible to install the applications on the host and then use the data from the flash drive but users should be careful to determine what information is contained on the host or its Windows registry. In some cases, names, passwords and other critical or identifiable information will be retained even when the flash memory drive is removed. This may not be a desirable alternative. Recommendations
The unit I used with this exercise was the 16-Gbyte Flash Voyager. It is also available in 4 Gbyte, 8 Gbyte and 32 Gbyte versions. Its rubber exterior is water resistant but not waterproof—so don’t take it swimming or diving. It will survive falls, liquids, and other nasties that can take down conventional flash memory drives though, which is always nice.

There is sufficient space on the larger versions to take all the approaches presented. The smaller versions will require a more selective approach to the options foregoing some to allow others to fit on the flash drive.

Go with the Flash Voyager GT if you can afford it. It is faster than the regular version although it is only available in the 16 Gbyte version at this time. Of course, the USB interface will need to be able to keep up with its performance. This was an issue with older PCs and the standard Flash Voyager but hopefully newer machines will be available should you go on the road with a Voyager.

Overall, I’ll keep the Flash Voyager around. If works often enough to be quite useful but you will still need to keep a laptop or mobile device with you for those instances where a compatible system is not available.



Topologi Linux




TAGS: Mobile
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