Install Debian on OS X Virtual Box Host

Download and install Virtual Box for OS X: https://www.virtualbox.org/wiki/Downloads
Download Debian Net Install: https://www.debian.org/CD/netinst/
Create a new machine named e.g. “Debian” and run it.
Select the Net Install disk (e.g. debian-8.2.0-amd64-netinst.iso) and start the installation
After the first successful login you may want to make your first snapshot
Login to the newly installed debian machine

To install the Guest Additions, start a terminal and type :

$ su
# aptitude update && aptitude safe-upgrade
# aptitude install module-assistant build-essential linux-headers-generic dkms
# m-a prepare

Click on Install Guest Additions… from the Devices menu. This will mount the disk in /media/cdrom and install the Guest Additions:
```
# sh /media/cdrom/VBoxLinuxAdditions.run
```
And Finally, reboot your machine:
```
# reboot
```
After this installation, you may want to make one more snapshot

Sharing folders Between Mac and Linux

On your Mac OS X host, get your user id:

$ id
uid=501(sbolay) gid=20(staff) groups=20(staff),12(everyone),61(localaccounts),66(_uucp),79(_appserverusr),80(admin),81(_appserveradm),98(_lpadmin),399(com.apple.access_ssh),33(_appstore),100(_lpoperator),204(_developer),395(com.apple.access_ftp),398(com.apple.access_screensharing)

Get your user and group id on Debian

sbolay@debian:~$ id
uid=1000(sbolay) gid=1000(sbolay) groups=1000(sbolay),24(cdrom),25(floppy),29(audio),30(dip),44(video),46(plugdev),108(netdev),111(scanner),115(bluetooth)

reboot your VM and at login prompt, press ctrl+cmd(+fn)+F1 and login as root
Convert the user id on Debian following the Mac one and add the user to the vboxsf group
```
# usermod -u 501 sbolay
# usermod -a -G vboxsf sbolay
```
Reboot and login
You can now share your Host folders from Devices → Shared Folders → … (e.g. /Users/sbolay)
Reboot and you should see your mounted folder in /media/sf_… (e.g. /media/sf_sbolay)

The initial user was >= 1000, and this is necessary to show up in GDM Login Screen. If your new ID is <1000, then your username will not show up in the GDM Login Screen and you will have to follow the link “Not listed?” and write your login!