In this article I want to document how to mount a external HDD device on a Raspberry Pi.
Configure your Pi
sudo raspi-config
- Expand Filesystem
- Change user password
- Change hostname
- Set boot to CLI
- Set GPU Memory to 16
- Update your localisation settings
Update your system
sudo apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade
Mount your external HDD
Now we can mount our storage. Please not that I’m using in this tutorial usbstorage, sda1 and as user pi. These are variables which you have to adjust depending on your system configuration and needs.
Prepare the Mount Point
First make a directory where your storage should be mounted.
sudo mkdir /mnt/usbstorage
Set the user permissions
sudo chown -R pi:pi /mnt/usbstorage
sudo chmod -R 775 /mnt/usbstorage
Set all future permissions for the mount point.
sudo setfacl -Rdm g:pi:rwx /mnt/usbstorage
sudo setfacl -Rm g:pi:rwx /mnt/usbstorage
Determine the USB Hard Drive Format
You need to knwo the file system the drive is formatted with
sudo blkid
/dev/mmcblk0p1: SEC_TYPE="msdos" LABEL="boot" UUID="787C-2FD4" TYPE="vfat"
/dev/mmcblk0p2: UUID="3d81d9e2-7d1b-4015-8c2c-29ec0875f762" TYPE="ext4"
/dev/sda1: LABEL="TrekStor" UUID="3d9d92e2-7d1b-4015-8c2c" TYPE="exfat"
Note the TYPE=”exfat” at the end, you will need this for the fstab file.
Now mount the usb stick. If it is NTFS you will need to install some utilities first.
sudo apt-get install ntfs-3g -y
If the drive is exfat install these utilities
sudo apt-get install exfat-utils -y
For all drive types mount the usb with this command, -o insures pi is the owner which should avoid permission issues
sudo mount -o uid=pi,gid=pi /dev/sda1 /mnt/usbstorage
If you get an error use this syntax
sudo mount -t uid=pi,gid=pi /dev/sda1 /mnt/usbstorage
If the mount -t command returns an error then use this syntax
sudo mount uid=pi,gid=pi /dev/sda1 /mnt/usbstorage
Automount the USB Hard Drive
/mnt/usbstorage will be the folder in which you store your media. We want it to be automounted on boot The best way to do this is through the UUID. Get the UUID by using this commmand
sudo ls -l /dev/disk/by-uuid/
You will see some output like this. The UUID you want is formatted like this XXXX-XXXX for the sda1 drive. If the drive is NTFS it can have a longer format like UUID=”BABA3C2CBA3BE413”. Note this UUID, for me it is BA8F-FFE8
total 0
lrwxrwxrwx 1 root root 15 Jan 1 1970 3d81d9e2-7d1b-4015-8c2c-29ec0875f762 -> ../../mmcblk0p2
lrwxrwxrwx 1 root root 15 Jan 1 1970 787C-2FD4 -> ../../mmcblk0p1
lrwxrwxrwx 1 root root 10 Oct 26 21:10 BA8F-FFE8 -> ../../sda1
Now we will edit fstab to mount the USB by UUID on boot
sudo nano /etc/fstab
Add the line in red to the bottom, replace XXXX-XXXX with your UUID and exfat with your type if it is different (e.g. ntfs, vfat, ext4). You may or may not need the quotation marks wrapped around the UID, you do not need quotation marks wrapped around the file system type (ext4, vfat, NTFS etc).
The umask 0002 sets 775 permissions so the pi user and group can read, write and execute files on the external USB drive. To completely eliminate permission issues you can set the umask to 0000 which equals 777 permissions so anybody can read, write and execute. Note that 777 permissions are considered a security risk.
If you have issues here then try replacing uid=pi,gid=pi with just the word defaults (typical for ext4). You can also try replacing the UUID with the /dev/sda1 line.
This is an example for exfat
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1
UUID=XXXX-XXXX /mnt/usbstorage exfat nofail,uid=pi,gid=pi 0 0
For NTFS, note that it is ntfs and not ntfs-3g
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1
UUID=XXXX-XXXX /mnt/usbstorage ntfs nofail,uid=pi,gid=pi 0 0
for ext4 using uid and gid is not recommended so use at your own risk as it could cause issues.
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1
UUID=XXXX-XXXX /mnt/usbstorage ext4 nofail,uid=pi,gid=pi 0 0
If you get any errors you can replace uid=pi,gid=pi with defaults or remove it entirely
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1
UUID=XXXX-XXXX /mnt/usbstorage ext4 nofail,defaults 0 0
For using /dev/sda1 and defaults if you have troubles with UUID
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1
/dev/sda1 /mnt/usbstorage ext4 nofail 0 0
Now test if the fstab file works
sudo mount -a
If you didn’t get errors reboot, otherwise try the suggestions above to get it working then mount -a again until it succeeds
sudo reboot
You should be able to access the mounted USB drive and list its contents
cd /mnt/usbstorage
ls
Every time you reboot, the drives will be mounted as long as the UUID remains the same. If you delete the partitions or format the USB hard drive or stick the UUID changes so bear this in mind. You can always repeat the process for additional hard drives in the future.
If you have multiple hard drives you will have to make separate mount points (e.g. /mnt/usbstorage2) for each drive’s partition
Fix Raspberry Pi 2 Mounting Issues
Apparently there is a bug in the Pi 2 that messes up automounting. You can fix it by creating a delay.
Open up the /boot/cmdline.txt files
sudo nano /boot/cmdline.txt
Add this line to the bottom, you can increase this delay if necessary
rootdelay=5
Hit Ctrl+X, Y and Enter to save and exit, then reboot to see if it automounts now. If the Raspberry Pi hard drive still does not automount we can use rc.local
sudo nano /etc/rc.local
Add this lines before the exit line
sleep 30
sudo mount -a
exit
Ctrl+X, Y and Enter to save
Reboot again to test
Appendix
- Unmount the disk
sudo umount /mnt/usbstorage