fedora on a flash drive

[Tyler Larson]

Florin Andrei wrote:
> Why Flash? The OS must survive power crashes and other nasty events
> without ever failing. If the data storage (which is on a regular HDD)
> fails, the OS will simply rebuild it, but in order to do that it must
> not fail itself.

There's certainly nothing unusual about running Linux from Flash 
ROM--Linksys does it :)--but doing so to increase reliability only makes 
sense if the dangers you're worried about can be solved by switching 
storage media.

A perfect reason to use flash media instead of hard disks is the moving 
parts issue. If your installation is subject to shock or vibration, hard 
disks are disasters waiting to happen. If you can eliminate the cooling 
fans too, you can have a zero-moving-parts computer, which can can be 
wonderful.

I can't come up with any possible reason why storing your data on a 
flash drive would make you any safer against a power failure. Journaling 
(and disabling hw cache) does that for you. If you lose power in the 
middle of a write with a journaled fs, you may lose your data (nothing 
can protect you there), but at least your filesystem will be in a 
consistent state. Remember, "consistent" doesn't mean "what you wanted", 
it means "safe to use". If you're writing to an SQL database when you 
lose power, your tables may not be in a consistent state, but at least 
the OS will boot. Certain RDBMS makers take great pride in their ability 
to maintain consistent state even after a power failure--but not all can 
do it.

If you're worried about storage device failure, RAID might be for you. 
If you're worried about power failure, a UPS may be in your future--get 
the kind that can signal the computer to shut down. If you're worried 
about damage to/by moving parts, Flash media is perfect.

Choose the fix that bests suits your problem. That's what I say.

Unless, of course, your fix is to use one of those gumstix computers. 
You're allowed to use those to fix anything. I've been searching for a 
year for a valid excuse ..er.. problem to solve with one of those.