On: Why RAID 5 stops working in 2009 (2007)

[ars]

> I should have set a cronjob to recursively md5sum my / every week or so

If you use Debian then install the debsums program which will do that for you for non-user data and report any errors.

You should also install mdadm and set it to check the array every month.

And finally install smartmontools and have it do a short self check every day and a long one (i.e. a full disk read) every week.