[Arm-netbook] Must watch video of GK802

[Gordan Bobic]

 On Fri, 11 Jan 2013 13:47:27 +0000, jm <joem at martindale-electric.co.uk> 
 wrote:

>> > This kind of thing should now be possible for all
>> > these matchbox computers because of f2fs.
>>
>> As you can see this was possible long before, despite some new FS.
>>
>> > F2fs keeps writing files to new locations and then cycle
>> > back to the beginning allowing even wear levelling.
>>
>> SD cards already do this on the h/w level.
>
> I know ssds do it, I wasn't aware sdcards can do it which is why
> they have a wear problem.

 They do it at the hardware level, but nowhere nearly as cleverly
 as a full fat SSD.

 Similar applies to most USB sticks and CF cards, although
 there are exceptions among those (some USB sticks contain
 proper SSD flash controllers, e.g. SuperTalent RC8 - they
 are essentially SATA SSDs with USB->SATA bridges.

 For example, see:
 http://www.altechnative.net/2012/02/07/morebetter-internal-storage-on-the-toshiba-ac100-part-2/

 IIRC my RC8 even has full SMART functionality I can access using
 smartctl.

>> > The great thing is that you can now yank out the OS
>> > and put a new OS in seconds. No way to brick a device.
>>
>> So it's just like any Allwinner A10-based device, while very nice, 
>> not any
>> super new achievement either.
>
> I was generally under the impression uSD cards are not reliable,
> but if they got over those problems by fitting it with Android,
> then its a smart move. With f2fs support, I think any Linux will now 
> do
> it properly.

 As I said before, I'm not all that concerned with reliability and
 wear leveling, but random-write performance is an issue. For
 this reason I've been using nilfs2 since it effectively turns
 all writes into sequential writes, but the garbage collection
 is a bit nasty the way it's implemented - it causes unnecessary
 wear by moving data blocks from tail to head even when the block
 is 100% clean. If it could handle garbage collection in
 non-contiguous way and do it in order of dirtyness, it would
 be much, much better. Having read up on f2fs since you
 mentioned it, it seems to be a decent compromise between
 nilfs2's total linearity and reasonably efficient garbage
 collection.

 Gordan