measuring the flash usage

[Brian Norris]

Hi,

On Tue, Sep 20, 2011 at 4:22 AM, Folkert van Heusden
<folkert.van.heusden at gmail.com> wrote:
> For an embedded system I'm working on I'd like to monitor the health
> of the flash memory.
> On regular Linux systems one can look at /proc/diskstats to see how
> often the system writes to a disk. It seems though that (at least
> kernel 2.6.19) for flash these counters are not updated.

I don't have much experience with the /proc/diskstats but for me, it
at least lists the mtdblockX devices I have on my system (which I
don't use). If you use those (for instance, for JFFS2?), then I would
imagine that Linux will track stats as with other block devices. Is
this not your experience?

> So I was wondering: are there any other ways?
> E.g. will the kernel log a message when it has problems writing
> to/reading from the flash memory? Are there any other counters
> anywhere?

Generally, MTD is pretty good at printing important messages, which
should get logged by your system. Also, bitflips/ECC errors can be
tracked with ioctl(ECCGETSTATS). This info is retrieved, for example,
by nanddump.

Others can probably comment better on other methods for tracking
health. Hope this helps.

Brian