>> SD cards are not hard drives. From what I have heard/read, they have
>> limits on the number of times data can be written to them before you
>> will wear them out. Writing to an SD card will usually require the
>> need to update the directory information so that portion of the
>> device can wear out faster. If the directory area gets worn out, you
>> will run in to all kinds of problems accessing your data.
>
> This is correct. You might only get 100,000 to 250,000 erase cycles on
> each block (2048 bytes?) and any update withing that block requires an
> erase and rewrite.
>
> I don't think you should be using Ext2/3 on Flash, you should be using
> a Flash File System, because these file systems do wear leveling so
> that erases are spread evenly across all the blocks.
>
SD cards, CFdisk cards etc all contain hardware that wearlevels!
So the myth that directory areas will wear out is just wrong.
There are plenty of web pages that explain what happens - google is your
friend. Start at the wikipedia article....
http://en.wikipedia.org/wiki/Flash_memory
Anyone who uses flash devices without attempting to truly understand what is
going on is asking for trouble.
For instance it is usually not possible to do flash file system on SD cards
because you need access to the flash memory devices - which you don't have.
The interface to the card is to the controller.
Ext2 is perfectly ok as a file system to these cards.
Any non-FFS journalling file system, like ext3, does carry a write penalty -
that is inherent in the concept of jounralling, and therefore be careful when
using ext3.
The advice to mount flash filesystems with noatime is good. Indeed it can give
performance improvements on standard Hard drive based file systems too.
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