ZPool & SMART status report with FreeNAS config backup

Original script by joeschmuck, modified by Bidelu0hm, then by melp

Preview of the output here: http://i.imgur.com/t9Mtqyt.png

At a minimum, you will need to enter your email address in user-definable parameter section. Feel free to edit other user parameters as needed.

Version: v1.3

Changelog:

v1.3:

• Added scrub duration column
• Fixed for FreeNAS 11.1 (thanks reven!)
• Fixed fields parsed out of zpool status
• Buffered zpool status to reduce calls to script

v1.2:

• Added switch for power-on time format
• Slimmed down table columns
• Fixed some shellcheck errors & other misc stuff
• Added .tar.gz to backup file attached to email
• (Still coming) Better SSD SMART support

v1.1:

• Config backup now attached to report email
• Added option to turn off config backup
• Added option to save backup configs in a specified directory
• Power-on hours in SMART summary table now listed as YY-MM-DD-HH
• Changed filename of config backup to exclude timestamp (just uses datestamp now)
• Config backup and checksum files now zipped (was just .tar before; now .tar.gz)
• Fixed degrees symbol in SMART table (rendered weird for a lot of people); replaced with a *
• Added switch to enable or disable SSDs in SMART table (SSD reporting still needs work)
• Added most recent Extended & Short SMART tests in drive details section (only listed one before, whichever was more recent)
• Reformatted user-definable parameters section
• Added more general comments to code

v1.0:

• Initial release

TODO:

• Fix SSD SMART reporting
• Add support for conveyance test