choice of flash file system for large read-only volume
ricard.wanderlof at axis.com
Thu May 17 17:06:40 EDT 2007
On Thu, 17 May 2007, Hamish Moffatt wrote:
> What would be a good choice of file system for this application? Does it
> come down to JFFS2 versus YAFFS, or are there other alternatives?
> I understand that JFFS2 mount times are proportional to the size; mount
> time isn't critical to me but I would like the system to boot as quickly
> as possible. Is YAFFS better in this regard?
One option you might consider if you have enough ram, is simply to make a
copy of a read-only file system such as cramfs in the flash, and upon
boot, copy it from flash to ram (skipping bad blocks of course), and
running it from there. Of course, you cannot write to cramfs, so that
would not be a good idea during development.
Since a straight copy from flash to ram can be reasonably fast, and
accessing cramfs in ram is quite fast, boot time is shorter to or
comparable to having the root partition directly in the flash as a jffs2
partition, in my experience.
Ricard Wolf Wanderlöf ricardw(at)axis.com
Axis Communications AB, Lund, Sweden www.axis.com
Phone +46 46 272 2016 Fax +46 46 13 61 30
More information about the linux-mtd