Strange Observation & One Question

This first one is more of an 'FYI' than an actual appeal for help :) My Debian Pogoplug is humming along just fine -- though I do run into the occasional weird behavior where strange things occur e.g. in one of my bash scripts, I have a line that contains a 'degree' symbol -- using 'vi' to edit that line goes crazy on my Pogoplug -- but on a normal Linux system it (of course) has no trouble. I had to edit the script externally and copy it to my Pogoplug in order to deal with this -- even the editor built into 'mc' did not work. Weird!

Next, I have some cron scripts running and doing work every minute -- and I have been trying to make sure that all the files that my own scripts create/change do so on the '/tmp' directory -- which is mapped to the 'tmpfs' file system (internal memory rather than storage). Can I be certain that NOT seeing the 'activity' light flash on my USB stick means that I am no long 'writing' to it -- and causing it to slowly wear out?

With regards to your first comment, I suspect your Pogoplug is using the wrong character set. (What exactly does "go crazy" mean?) Try echoing $LANG on both your desktop system and your Plug. I bet the Plug is set to "C" and the desktop to something like "en_US.utf8". If you need to edit files with special characters (those not in the ASCII character set) on your Plug, you might try loading the "vim" package. It provides a lot more flexibility over the base "vi".

I think you are correct with regard to your second point -- the flashing activity light on your USB stick -- although this is ultimately a function of the individual stick. Another thing you might try is

$ grep sda1 /proc/diskstats

(substituting the mounted partitions from your USB stick for "sda1". The output is:

Field 1 -- # of reads issued
Field 2 -- # of reads merged
Field 3 -- # of sectors read
Field 4 -- # of milliseconds spent reading
Field 5 -- # of writes completed
field 6 -- # of writes merged
Field 7 -- # of sectors written
Field 8 -- # of milliseconds spent writing
Field 9 -- # of I/Os currently in progress
Field 10 -- # of milliseconds spent doing I/Os
Field 11 -- weighted # of milliseconds spent doing I/Os

By comparing field 5 and field 7 from several invocations of the command, you can get an idea of how much write activity is occuring to that partition.

Thanks restamp! You are 100% correct on both points!

Ah, another strange behavior that I got caught on is due to my own sloppiness and laziness: some shell scripts that I had written worked fine when *I* ran them, but failed when *cron* did...

It turns out that the 'sh' shell (dash?) was being used by cron, but my own foreground sessions were using 'bash' (which is normal for me). I had to make sure that I added the typical '#!/bin/bash' at the top of my scripts to keep things consistent.

It's wise to always specify the shell in the script itself, as darethehair suggests, but if you want to always use a particular shell in cron, you can do this by specifying

SHELL=/bin/bash

as the first line of your crontab. (You can also specify "PATH=...", and/or other environment variables, at this point.)