Getting top 5 folder sizes (recursive) in the current directory

du -hs * | sort -rh | head -5

Recursive File Count In A Directory

This command is useful for finding a cache directory with 1000's of files.

find . -type f | wc -l

Replace . with path if you want a count from other than the current directory.

Empty File Content by Redirecting to Null

The easiest way to empty or blank a file content is by using shell redirect null (non-existent object) to the file:

root@server# > access.log

Checking Disk Performance

https://askubuntu.com/questions/87035/how-to-check-hard-disk-performance

sudo hdparm -Tt /dev/sda

RAID Resize Array

• Launch RAID utility
• Create a new logical array with 1 or more drives
• Launch OS from USB
• Copy disk, including all partitions from old array
• Remove old array and reboot without USB to make sure it works
• Launch OS (with GParted) from USB and resize partitions as needed
• Resize LVM to fill partition
• Resize file system to fill LVM

Create a directory that also creates parent paths

mkdir -p foo/bar/baz