I had a system running a 128MB live CD image with 2.8 gigs of available RAM and the OOM kernel killer went crazy when using dd for more than 8 minutes and kept killing everything. I've read that this is due to a low-memory issue and paging in the kernel and 32-bit systems with lots of RAM.
I even enabled swapspace on my LiveCD and the issue happened 25 minutes into dd rather than 8 minutes, so what gives?
Also no swap space was ever used!
cat /proc/s........
This made me nervous but it's clearly a cronjob based on the messages log that happens every Sunday at about 4:22.
I actually can't find any evidence of it in cron.d cron.daily but it is there somewhere obviously.
What I don't get is why doesn't this cronjob do a datacheck like Ubuntu's cronscript does? When you unnecessarily rebuild the array you lose your redundancy during that point which makes your data extremely vulnerable.
*Update I did a grep of &q........
This really made me nervous but notice the mdstat says "check". This is because in Ubuntu there is a scheduled mdadm cronscript that runs everyday on Sunday at 00:57 that checks your entire array. This is a good way because it prevents gradual but unnoticed data corruption which Inever thought of.
As long as the check completes properly you have peace of mind knowing that your data integretiy is assured and that your hard drives are functioning properly (I'........