Knoppix on USB flash memory

**robbika** · 06-04-2003, 05:30 PM

I have noticed that now it is possible to get USB flash memory up to 1 Gb.

Although it would be very very expensive at the moment, is it technically feasible to boot Knoppix from an external USB flash memory?

Is USB 2.0 flash memory speed fast enough, and would it be faster than from CD-ROM?

**garyng** · 06-05-2003, 01:14 AM

1x CD is 150KB/s so 50x would be 7.5MB/s, USB 2.0 is 480(?) Mb/s or 60MB/s. Putting overhead aside and assume the flash can reach that speed, yes. However, none of the off-the-shelf flash can have that speed. It would be at best comparable but I guess in general slower if the claim of 48x CD is real(that I have no idea).

BTW, I am thinking along the same line but instead of 1GB, I am aiming at the 256M CF which is very cheap nowadays. A trim down KNOPPIX can fit into it and there would still be some space for persistent home. The only problem is machine supporting USB booting is still not the majority.

**aay** · 06-05-2003, 05:08 AM

Here are a few links to consider the speed of cf as well as mmc and sd cards.

http://www.dpreview.com/articles/mediacompare/
http://www.davespda.com/hardware/expansion/cfmmcsd.htm
http://www.amazon.com/exec/obidos/tg...952374-5295339

The general concensus seems to be that cf is the fastest of these three media, but that even it is not as fast as a cd.

Getting Knoppix to run off of this media should be possible as long as your bios supports booting from usb. However as some of the posts at knoppix.net indicate you will have to tweak things because Knoppix is set up by defalut to expect to see itself mounted on a cd.

What's interesting about this approach is not so much the speed of CD's vs the speed of CF cards but rather the fact that you can write to a CF card.

If you do intend to write to it then you will either need to shrink Knoppix, or get a really big CF card (3GB is the largest I've seen) since Knoppix is compressed.

**reub2000** · 06-06-2003, 12:32 AM

It would be at best comparable but I guess in general slower if the claim of 48x CD is real(that I have no idea).

48X claim is only on the edge of the disc. Also, at less than a dollor, a cd is a lot cheaper than flash ram.

You could look at some of the lighter remasters, copy the cloop compressed file, then boot via a bootfloppy (if the floppy searches the flashram, I don't know), and see if it works.

**elgaard** · 07-18-2003, 10:56 AM

[quote="aay"]
> However as some of the posts at knoppix.net indicate you >will have to tweak things because Knoppix is set up by >defalut to expect to see itself mounted on a cd.

I dont think so. Knoppix tries to boot any /KNOPPIX directoty on a SCSI mountable drive.

--
Niels

**zhrinze** · 08-06-2003, 08:25 AM

Originally Posted by reub2000

It would be at best comparable but I guess in general slower if the claim of 48x CD is real(that I have no idea).

48X claim is only on the edge of the disc. Also, at less than a dollor, a cd is a lot cheaper than flash ram.

You could look at some of the lighter remasters, copy the cloop compressed file, then boot via a bootfloppy (if the floppy searches the flashram, I don't know), and see if it works.

While it's true that a CD is cheaper, I can build a computer with *no* moving parts once the CD is transferred to compact flash. Further, the power consumption of a laser is higher.

There's a $600 computer complete with case that is Linux friendly and for $30 you can purchase a CF reader that plugs into the IDE adapter on the motherboard. You only cost then is the CF itself. While expensive, I can run it all day with very little power. Of course I can do this with any version of Linux. An install version of Knoppix would be great for this.

**drboo** · 08-13-2003, 04:53 PM

I have had this dream for a while myself. Has anyone been able to find substancial data on how many bios's these days support USB booting? I'd love to have a 256Mb keychain drive with a bootloader and some small versions of livecds for different hardware (x86/PPC/Sparc)

**Pjotr** · 08-17-2003, 05:17 PM

Originally Posted by garyng

1x CD is 150KB/s so 50x would be 7.5MB/s, USB 2.0 is 480(?) Mb/s or 60MB/s. Putting overhead aside and assume the flash can reach that speed, yes. However, none of the off-the-shelf flash can have that speed. It would be at best comparable but I guess in general slower if the claim of 48x CD is real(that I have no idea).

BTW, I am thinking along the same line but instead of 1GB, I am aiming at the 256M CF which is very cheap nowadays. A trim down KNOPPIX can fit into it and there would still be some space for persistent home. The only problem is machine supporting USB booting is still not the majority.

A typical Flash disk speed is about 2-3x USB 1.1. So you are talking about 1 MB/s for USB 1.1 flash disks and no more than 2-3 MB/s for USB 2.0 flash disks.

However, many people have already made USB flash disk bootable Linuxes, from 16 MB and up. Devices above 256 MB costs more than the size increase.

**Pjotr** · 08-17-2003, 05:20 PM

Originally Posted by drboo

I have had this dream for a while myself. Has anyone been able to find substancial data on how many bios's these days support USB booting? I'd love to have a 256Mb keychain drive with a bootloader and some small versions of livecds for different hardware (x86/PPC/Sparc)

Only the modern motherboards supports this. If you take an average hobbyist computer, I'd bet it doesn't support it. If you want to build computers with this function, you can easily find motherboards today.

Don't build a distribution that uses the USB disk for frequent writing. Flash devices supports about 1 000 000 write cycles during their lifetime. This may sound much but in reality is very little. If your OS runs from the USB like a HD, you will burn out the USB flash disk quickly. So stick to only writing few times, like saving configs etc. Use RAM disks for runtime info.

**reub2000** · 08-18-2003, 09:59 AM

Originally Posted by zhrinze

Originally Posted by reub2000

It would be at best comparable but I guess in general slower if the claim of 48x CD is real(that I have no idea).

48X claim is only on the edge of the disc. Also, at less than a dollor, a cd is a lot cheaper than flash ram.

You could look at some of the lighter remasters, copy the cloop compressed file, then boot via a bootfloppy (if the floppy searches the flashram, I don't know), and see if it works.

While it's true that a CD is cheaper, I can build a computer with *no* moving parts once the CD is transferred to compact flash. Further, the power consumption of a laser is higher.

There's a $600 computer complete with case that is Linux friendly and for $30 you can purchase a CF reader that plugs into the IDE adapter on the motherboard. You only cost then is the CF itself. While expensive, I can run it all day with very little power. Of course I can do this with any version of Linux. An install version of Knoppix would be great for this.

No moving parts? What about a cpu and psu fan? And maybe a northbridge fab?