Determine filesystem on Linux

df -T [device]
NOTE: for partitioned FS we should look for [device1], [device2] etc - e.g. /dev/sdf1, /dev/sdf2 (/dev/sdf FS type could be unknown in this case)
http://www.cyberciti.biz/faq/linux-how-to-determine-find-out-file-system-type/

Linux: Show all files modified in the last X days

> find -mtime -2 -print # where 2 is the number of days back