Diskutil

• List all the disk that are plugged to the machine
  diskutil list

• Force a disk to mount
  mount disk1

• Check smart status if available

http://hints.macworld.com/article.php?story=20031122041138373

diskutil info disk0 | grep SMART

Check the smart status on external drive Install https://github.com/kasbert/OS-X-SAT-SMART-Driver#readme

http://apple.stackexchange.com/questions/52604/can-i-get-s-m-a-r-t-support-on-external-hard-drives

Disabling spothlight (indexing by mac)

http://osxdaily.com/2009/09/20/disable-spotlight-in-mac-os-x-10-6-snow-leopard/
sudo mdutil -a -i off

This tells the Spotlight manager to disable all indexing on all volumes, the command will require your administrative password to execute.

Re-enabling Spotlight in Mac OS X 10.6 Snow Leopard is just as easy, just reverse the command to:

sudo mdutil -a -i on

Now Spotlight indexing will be back on and work as usual.