[Lazarus] Using Lazarus on Embedded Linux?
henry.vermaak at gmail.com
Tue Sep 28 11:56:45 CEST 2010
On 28/09/10 10:18, Michael Schnell wrote:
> Independent from the kind of the hardware interface to the card, the
> problem is that
> - in Linux you think you are safe if you unmount the file system before
> powering off
> - when using a journaling file system you are sure that you always can
> power off the system and when restarting the file system will restart
> after the latest completed written transaction, with all previous data
> being safe and a clean file system structure.
No. If you have a disk that does out of order write caching, you will
have to enable barriers (which are not enabled on ext3 by default, for
example). Then you may still have the problem of some disks not
implementing the flushing correctly, at which point you will have to
disable the write caching, which will have a big performance impact.
My point is that you are always at the mercy of your device (not just
with sd/mmc). A good sd/mmc will implement a log structured file system
in the translation layer that won't be prone to data loss.
These are corner cases, though, and I fear that we're very far off topic
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