Useful Commands

Rsync

rsync -vaopHDS --stats --ignore-existing -P (Source) (Destination) 

-v, --verbose
-a, --archive (It is a quick way of saying you want recursion and want to preserve almost everything.)
-o, --owner
-H, --hard-links
-D, --devices (This option causes rsync to transfer character and block device information to the remote system to recreate these devices.)
-S, --sparse (Try to handle sparse files efficiently so they take up less space on the destination.)
-P (The -P option is equivalent to --partial --progress.)

Fixing perms for a website

find /home/USERNAME/public_html/ -type f -exec chmod 644 {} \; && find /home/USERNAMER/public_html/ -type d -exec chmod 755 {} \;

ddrescue

ddrescue -f -n -r3 /dev/[bad/old_drive] /dev/[good/new_drive] /root/recovery.log

-f   Force ddrescue to run even if the destination file already exists (this is required when writing to a disk). It will overwrite.

-n   Short for’–no-scrape’. This option prevents ddrescue from running through the scraping phase, essentially preventing the utility from spending too much time attempting to recreate heavily damaged areas of a file.

-r3   Tells ddrescue to keep retrying damaged areas until 3 passes have been completed. If you set ‘r=-1’, the utility will make infinite attempts. However, this can be destructive, and ddrescue will rarely restore anything new after three complete passes.

SSH tunneling

-f will put the SSH in bg, -L = local, the 666 will be the port that will be opened on the localhost and the 8080 is the port listening on the remote host (192.168.1.100 example). 

ssh -f root@my-server.com -L 666:192.168.1.100:8080

Force reinstall all arch packages

pacman -Qqen > pkglist.txt
pacman --force -S $(< pkglist.txt)