[time-nuts] 5370 processor boards available

Hal Murray hmurray at megapathdsl.net
Thu Feb 27 03:26:13 EST 2014


> I think a better solution would be to find a very large "super cap" and
> power the BBB from that while giving it a power fail interrupt to quickly
> sync the file system.

The advantage of something like the BBB is that it runs Linux so you have a 
nice environment in which to run your code.  The disadvantage of Linux is 
that it's complicated and you have things like file systems that can get 
trashed.  Now, in addition of being the sysadmin for your PC(s), you have to 
be an admin for your lab gear.  That may be more "interesting" that you were 
expecting.  A friend reports that his scope caught a virus...

The Linux ext4 file system is pretty robust.  There are lots of PCs out there 
that mostly survive power failures.

If I was worried about the file system getting trashed on power off, I'd work 
on the software long before I added a super-cap.  I think my first try would 
be to run the file system read-only until I figured out that I needed to 
write a file.  Then I would know something about how much data I wanted to 
write and the usage patterns.

You can help a lot with flush() in the right places in your code.  That may 
cost performance if you are writing a lot of data.

--------

Another approach is to make sure you can put the "disk" back together easily 
and quickly.  Then it's not such a big deal if/when the disk gets trashed.  
That's probably a good idea anyway.  Power fail isn't the only thing that can 
trash a disk.

It shouldn't take much more than a simple script to format the disk and copy 
over all the bits from a backup place on a PC.  Maybe it's install the 
standard distro package and then add your bits.  (That's assuming you can 
take the disk out of the BBB and plug it into a PC.)







-- 
These are my opinions.  I hate spam.





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