MozillaQuest the on-line computer magazine

11 January, 2006

Office and Productivity Software

SCO IP, SCO v Linux, & Caldera v IBM

Live Knoppix Is Very Nice Desktop Linux

Cheat Knoppix 4 to Improve Performance

Part 2. Knoppix Performance Improvement Cheats

A side benefit of moving the CD image to a USB Flash drive (USB Key) is that it also frees the CD/DVD drive in which you placed the Live Knoppix CD or DVD.

Mike Angelo -- 11 Janaury 2006 (C) -- Page 1

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Editor's Note: This article is entirely too long. So, we broke it down into a four-part series. Each of the four parts seems somewhat independent of the other parts. However, the knowledge and skills you pick up in each part are necessary for all, but the advanced reader, to fully understand the other parts.

You might be able to jump into a specific part and understand it completely. If not, you can start at the beginning of the series and read through to the end -- your choice.

Please check the Article Index below to see how the parts are laid out and what is covered in each part. Links will be activated as each part is published. Ed.

Article Index

[Part 1. Cheat Code Basics and the ALSA Cheat Code]

[Part 2. Performance Improvement Cheats]

[Part 3. Advanced Cheating]

[Part 4. Computer on a Disc and a USB Key]

Persistent Knoppix
Conclusion

Resources

Books

"What is KNOPPIX?"

"KNOPPIX is a bootable CD or DVD with a collection of GNU/Linux software, automatic hardware detection, and support for many graphics cards, sound cards, SCSI and USB devices and other peripherals. KNOPPIX can be used as a productive Linux desktop, educational CD, rescue system, or adapted and used as a platform for commercial software product demos. It is not necessary to install anything on a hard disk. Due to on-the-fly decompression, the CD can have up to 2 GB of executable software installed on it. (over 8 GB on the DVD "Maxi" edition)." Knoppix Information (Link in the Resources section on Page 3.)

Knoppix is based on the Debian Linux distribution.

To learn why Linux is so much a better choice than is Microsoft Windows, please see our article Gaël Duval Tells Why Mandrake Linux Is Better Than MS Windows

Office on the Linux Desktop

A Glimpse of OpenOffice 2.0 -- Now Available for Free Public Downloading

OpenOffice 1.1 -- A Complete Office/Productivity Software Suite for GNU-Linux, FreeBSD, MAC, MS-Windows, Unix, and more

Creating a Simple Newsletter with OpenOffice/StarOffice Writer - a free word processor

Creating a Simple Contact or Personal Information Manager with OpenOffice/StarOffice Calc - a free spreadsheet

Creating a Personal or Company Budget with OpenOffice/StarOffice Calc - Part 1: Basics

USB Flash Drive (USB key) Caution:

USB keys use flash memory for their storage media. "Both types of flash memory and EEPROM wear out after many erase operations, due to wear on the insulating oxide layer around the charge storage mechanism used to store data. A typical NOR flash memory unit wears out after 10,000-100,000 erase/write operations, a typical NAND flash memory after 1,000,000." (Flash memory from Wikipedia, the free encyclopedia. Link in the Resources section at the end of this article.)

"When compared to a hard disk drive, a further limitation is the fact that flash memory has a finite number of erase-write cycles, so that care has to be taken when moving hard-drive based applications, such as operating systems, to flash-memory based devices". (Ibid)

This would seem to suggest that using a USB flash drive for heavy-duty reading and writing, might not be such a good idea. That's because there would be lots of erase operations, which could wear down the insulating oxide layer.

The persistent Knoppix trick could result in lots of write operations to the USB flash drive (USB key) discussed in the Persistent Knoppix section of this article. Thus, the Wikipedia discussion would suggest that one should not use a USB flash drive (USB key) for the persistent Knoppix trick. That notwithstanding, we used a USB key for the persistent Knoppix trick anyway.

It's your choice. You can abide by the Wikipedia caution and not use a USB key or any other flash memory device for that matter for the persistent Knoppix trick. Or, you can throw caution to the wind as we did and use a USB key anyway. If you do so, you are proceeding at your own risk.

On the other hand, using a USB flash drive (USB Key) to hold the Knoppix live CD image for read-only use as discussed for the performance cheat ought to be OK. It seems likely the read-only performance cheat would not affect the insulating, oxide layer around the charge-storage mechanism used to store data. However, this is speculation. We have not tested the effect on the insulating, oxide layer when using a USB key for holding the live CD image.

Two important problems with live Linux distributions are (1) they are slow and (2) they tie up a CD/DVD drive. Today, in Part 2, this Knoppix tutorial shows you how to use Knoppix cheats to speed up Live Knoppix. And it shows you how to free the CD drive or DVD drive that you use to run Live Knoppix too.

Today's tutorial builds on what you learned in Part 1. Cheat Code Basics and the ALSA Cheat Code. In Part 1, we covered Knoppix cheat code basics and applied those basics to forcing Knoppix to use the ALSA sound drivers rather than the default OSS sound drivers.

Coming after Part 2, are Part 3. Advanced Cheating and Part 4. Computer on a Disc and a USB Key. You will learn about more Knoppix cheat codes and how to chain several cheat codes together in Part 3. And then in Part 4, you will learn how to put together all the stuff you learned in Parts 1 through 4 to make a very portable Live Knoppix setup. It's really very slick.

If you already have not done so, please read Part 1. Cheat Code Basics and the ALSA Cheat Code. Doing so will get you up to speed on the basics of using Knoppix cheat codes.

Preview

The performance problem was addressed by using two Knoppix cheat codes. The first performance cheat, tohd=/dev/sda1, let's you copy the Knoppix live Linux CD onto a USB key. We used a 4-GB Kingston DataTraveler Elite Flash drive (USB key) for that.

The second performance cheat, fromhd=/dev/sda1, let's you use that USB key when running the Knoppix live Linux CD. Interestingly, this cheat also releases the CD drive too. So, you might want to do this performance cheat just to free the CD drive.

The details of using these performance cheats are discussed further on in this article.

Incidentally, if you like you can chain several cheats at the boot: prompt. For example you can direct Knoppix to do both the ASLA cheat and the performance cheat. That's covered in Part 3. Advanced Cheating.

You can setup the USB key you use for the performance cheats to store your configuration files, data files, and so forth. Doing that makes your Live Knoppix Linux very portable. Make sure you read that section. It's covered in Part 4. Computer on a Disc and a USB Key.

The Performance Cheats

By default, the live CD/DVD Knoppix system uses its files on the CD/DVD to install the Linux kernel in a ram disk. It also uses the live CD/DVD for other files needed to run the Knoppix version of the Linux operating system. And Knoppix uses the live CD/DVD for the applications you use to do your work or to play.

That also locks the CD/DVD drive in which the Knoppix live CD/DVD is placed. If you have only one CD/DVD drive on your computer you are not able use other CDs or DVDs during Live Knoppix sessions.

If you have a computer system with a fast CPU, lots of RAM (hard memory), and a fast CD/DVD drive, you might not notice how much time it takes for the system to repeatedly look to the Knoppix live CD/DVD. The system looks to the live CD/DVD in order to grab OS and application files, as it needs them -- in order to execute them or to use their data.

If you run the live CD/DVD version of Knoppix on a less well-endowed system, you likely will experience and notice slow performance. Even on a faster machine where you might not notice slower performance, those relatively slow CD/DVD reads are affecting system performance. That's because Knoppix is frequently grabbing files and information from the relatively slow CD/DVD drive.

One way to perk the performance of your live CD/DVD version of Knoppix Linux is to move the CD image to a USB Flash drive (USB Key). Luckily, there are some nice Knoppix cheats to do that.

A side benefit of moving the CD image to a USB Flash drive (USB Key) is that it also frees the CD/DVD drive in which you placed the Live Knoppix CD or DVD.

You might be able to copy the live CD/DVD image to your hard drive or to RAM instead of a USB key. However, the focus of this tutorial is on using a USB key (USB Flash drive). Nevertheless, the general methodology is the same whether you copy the live Linux CD or DVD to a USB key, to a hard drive, or to RAM. There are special cheat codes copying the live Linux CD or DVD to a hard drive and to RAM.

Use a USB Flash Drive (USB Key) to Improve Performance

The USB Key, performance-cheat discussion is constrained to the live CD only. That's because the Knoppix live DVD has about 4 gigabytes of files -- too much for a USB key at this time. If you have ample room on your hard drive or enough RAM, you could do a similar cheat to copy the live CD or DVD image to a hard drive or to RAM. However, you would use different cheat-code strings for the hard drive or RAM cheats.

You might be able to squeeze the Knoppix live DVD files onto a 4-GB USB key. However, even if you can do that you likely would not have enough free space left on the USB key for your configuration and data files too. Thus, this USB Key, performance-cheat discussion is constrained to the live CD only.

One reason for copying the live CD files to a USB key is that access to files is much faster with a USB Key than it is with a CD drive. Kingston rates its 4-GB DataTraveler Elite USB key at a read speed of up to 24-MB/second and a write speed of up to 14-MB/second.

Compare that to a 40X CD drive, which has a maximum read speed of only 6-MB/second. That makes the DataTraveler Elite read speed about 4 times faster than a 40X CD drive.

The performance advantage is even more pronounced with the old HP OmniBook laptop. Its CD drive has only a 6X read speed -- 0.9-MB/second. That makes the DataTraveler Elite about 26 times faster than the CD drive on the OmniBook.

What if you have a more powerful and better-endowed computer? You still might want to use a performance cheat such as the one discussed here to copy the CD/DVD image to RAM, a hard drive, or a USB key. You might not be able to notice the performance improvement under a light load. But, when the load gets heavy, the performance improvements gained by copying the live CD Knoppix to the USB key will make a difference.

Copying the live CD files to RAM provides even faster access to the files. However, you need at least a 1-GB RAM to do that. So, copying the live CD files to RAM is not an option with our HP OmniBook 6000 laptop, which has only a 128-MB RAM.

Another reason for copying the Knoppix live CD files to a USB Key is that our HP OmniBook 6000 laptop has only a 10-GB hard drive -- and there is not enough free disk space to copy the live CD files to the hard drive.

Also, the main reason for using a live CD is that you do not want to install Knoppix and/or Linux on your computer. Nor do you want to put anything on your hard drive while you are using live CD Linux. By using a USB key for this performance cheat you do not have to put anything on your hard drive. However, please see the Hard Drive Use Note in the right sidebar on Page 2.

Yet another reason for choosing a USB Key for the performance cheat is so that you can use the Knoppix live CD on several different computers -- and have the same configuration on whatever computer is being used with the Knoppix live CD. For more about that, please see the Knoppix is a portable computer on a disc and USB key section in our article Give the Gift of Knoppix Linux and a Book for Less Than $30 and also the Persistent Knoppix section later on in this article.

There is a nice section about performance cheats in Knoppix Hacks under Hack #5. If you go to the Knoppix Hacks Web site, you will find that Hack #5 is the online sample chapter. (Link in the Resources section at the end of this article.