Gentoo Archives: gentoo-embedded

From: Peter Stuge <peter@×××××.se>
To: gentoo-embedded@l.g.o
Subject: Re: [gentoo-embedded] crash proofing a system from power cutoffs
Date: Mon, 23 Jan 2012 19:04:00
Message-Id: 20120123185540.927.qmail@stuge.se
In Reply to: [gentoo-embedded] crash proofing a system from power cutoffs by Kfir Lavi
Kfir Lavi wrote:
> I'll need to crash proof a Gentoo system from electricity cutoffs.
Then you need backup power. There is no other solution.
> I have a system with 8GB of flash drive.
As others have indicated, the particular type of flash "drive" is very significant, because the electronics between CPU and flash chip is obviously in control of writing and caching. If you are using anything other than an mtd interface then you have much worse odds of being able to survive power loss.
> I created a small system ~100mb as the target system. > I thought of creating 5 200mb paratitions of raid1. So 5 will be > mirrored. What do you think of this solution?
RAID does nothing.
> Do you have more ideas how to keep the system intact ?
See above.
> I'm creating ext4 partitions, but would like to hear some opinions > on that fileystem.
Without mtd you are in such a bad situation that it almost doesn't matter what you do on top of the block device as long as it's journalled. Of course if all partitions are mounted ro then there is no problem. If you need write then make sure to use mtd hardware and jffs2 or such. //Peter