[Cerowrt-devel] Is there a particular reason cerowrt isn't using UBIFS?

Theodore Ts'o tytso at mit.edu
Sun Aug 31 12:45:31 EDT 2014


On Sun, Aug 31, 2014 at 12:05:52AM -0700, David Lang wrote:
> 
> One other place this sort of thing is likely to be useful is for Raspberry
> Pi and other small (embedded by some defintions) systems that use SD cards
> for their OS system. The I/O to the storage is so slow that the saved I/O
> time is likely to more than cover the cost of the decompression.

Yeah, that's the main argument I've heard for wanting to do
decompression; it's to speed up I/O when using HDD's and cheap flash
that has a minimal number of flash channels.

> Raspberry Pi systems have had to move to 4G cards as their base because it's
> just not possible to have the standard install do more than boot on a 2G
> card.

2G SD cards --  $42.95 for a 10-pack
4G SD cards --  $53.95 for a 10-pack

I have a design for adding compression, but except as a hobby effort,
I've had a lot of trouble finding a company who would be willing to
support an engineer to actually do the effort.  :-( 

Unless the company is making a truly vast number of devices, and are
very sensitive to the BOM cost, it might not make sense from an
engineering / business plan point of view.

So it will probably be something I do "for fun", when I can find the
time.... and there are a lot of other projects where companies are
willing to sponsor engineers to add new features, such as encryption,
reflink support, data checksums, etc., where if I can help them land
those features, it's unfortunately going to be higher priority than my
personally working on compression support for ext4.

But if someone is interested in working on it, they should talk to me;
I'd be happy to work with someone interested in working on the
project.

							- Ted



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