AboutPuppy

Flash memory has only about 100,000 write cycles. After that the particular cell cannot be overwritten reliably. At least some devices (CF) have automagical management of errors and remapping, and "wear leveling" features to keep one spot from burning out from overuse.

Standard Linux makes frequent write to log files such as /var/adm/log /usr/log and others.

Any Linux suitable for flash memory sticks (called "flash puppy" or Linux-on-a-stick) must therefore reduce writes to the mem-stick by:

* using ram-disk
* using ram-disk and union-fs (as in puppy 1.0.1)
* allowing for read-only switchable mem-sticks (with a little mechanical switch on the case of the stick)
* using swap partitions

flash-puppy once started up leaves the USB stick totally alone, preserving its lifetime, so you can even pull it out, e.g. for security concerns. On shutdown it wants to write all new and downloaded files in the home dir (/root , as you are the user "root" typically) back to the stick - if it is not plugged in, changed data from /usr ( /root/.usr/) and homedir is lost. In some cases this might even be desirable (virus or whatever).

flash-puppy uses ram-disk only and does not write log-files or stuff to flash-mem like hard-drive based linuxes or other live CD's, given enough RAM e.g. 256 RAM with 128 stick, 512 MB RAM w/ 256 MB USB pendrive.

It is possible to write to the stick manually, though, which would typically be infrequent.

This is why it is not advisable to just remaster KNOPPIX onto a flash-stick, because the stick would soon be rendered unusable. Some computer magazines in print seemingly are unaware of the fact that there are these special solutions to the linux-on-a-stick problem - worked out already.

See also

CF-IDE Adapters

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CategoryHardware