WINDOWS

Xcopy /E /I C:\dir1\sourcedir D:\data\destinationdir

xcopy /C/H/R/S/Y c:\ d:\

/E = This option makes sure that empty subfolders are copied to the destination.
/C = Continues copying even if errors occur
/H = Copies hidden and system files also
/R = Overwrites read-only files
/S = Copies directories and subdirectories
/Y = Overwrites existing files without asking
/I = Avoids prompting if the destination is a folder or file. Not required if you are adding a trailing ‘\’ to the destination folder, like below.

robocopy c:\ d:\ /MIR /R:0 /W:0

/MIR = Mirror entire directory structure (can use /E instead)
/R:0 = 0 retries for read/write failures
/W:0 = 0 seconds between retries

MAC

If your mac errors when installing the OS from the internet recovery, open the terminal and type the following:

date -u 0410085020

SSL

openssl req -new -newkey rsa:2048 -nodes -keyout your-domain.key -out your-domain.csr

APACHE

sudo adduser www-data sudo chown -R www-data:www-data /var/www sudo chmod -R g+rwX /var/www