We have half a dozen questions asking about a boot-time SMART warning:

* https://superuser.com/questions/512695/on-booting-my-laptop-warns-me-about-failure-of-hard-disk-is-imminent-can-it-be
* https://superuser.com/questions/129094/is-there-a-script-to-disable-a-smart-hard-drive-failure-is-imminent-message
* https://superuser.com/questions/443287/warnings-on-hdd-failure
* https://superuser.com/questions/341779/how-to-fix-failure-predicted-on-primary-slave-wdc
* https://superuser.com/questions/531972/s-m-a-r-t-failure-predicted-in-harddisk
* https://superuser.com/questions/576197/what-are-reasons-for-smart-failure-predicted-on-hard-disk-error

Should we have a canonical question dealing with this? Or just collect the existing ones under one question? Some answers are effectively duplicates cross-question, so plain merging may not be appropriate.