Mounting external hard disk to Raspberry Pi

Why?

I had to access the contents of an internal hard disk (1TB, 3.5 inch) of an old inoperational computer.
This post explains how I turned this hard disk to into a Network Attached Storage (NAS) using Raspberry Pi.

External HDD

I used this external hard drive enclosure.
Now, External hard disk drive is ready which is powered by its own power supply.
Raspberry can turn the external hard disk into a network attached storage system.

Mounting the hard disk

1. Power up the external hard disk and connect its USB cable to Raspberry Pi.

2. Check if the device is listed using sudo blkid.
   Also, we can use fdisk -l to see more details.

    $ sudo blkid
    /dev/mmcblk0: PTUUID="b3c5e39a" PTTYPE="dos"
    /dev/mmcblk0p1: SEC_TYPE="msdos" LABEL="boot" UUID="7771-B0BB" TYPE="vfat" PARTUUID="b3c5e39a-01"
    /dev/mmcblk0p2: UUID="c7f58a52-6b71-4cea-9338-65f3b8af27bf" TYPE="ext4" PARTUUID="b3c5e39a-02"
    /dev/sda1: LABEL="STORAGE" UUID="7769-6306" TYPE="vfat" PARTUUID="00087f73-01"
    /dev/sda2: LABEL="MOVIES VOL1" UUID="7B43-35C9" TYPE="vfat" PARTUUID="00087f73-02"
    /dev/sda3: LABEL="MOVIES VOL2" UUID="7F56-80F3" TYPE="vfat" PARTUUID="00087f73-03"
    /dev/sda5: LABEL="MOVIES VOL3" UUID="A0B49E2DB49E05C6" TYPE="ntfs" PARTUUID="00087f73-05"
    /dev/sda6: LABEL="MY WORKS" UUID="C44CB9B74CB9A518" TYPE="ntfs" PARTUUID="00087f73-06"
    /dev/sda7: LABEL="TRANSFERS" UUID="867CE49C7CE4886F" TYPE="ntfs" PARTUUID="00087f73-07"
   

3. Create required directory structure in /mnt for all partitions.

    cd /mnt
    sudo mkdir storage
    sudo mkdir -p movies/vol1
    sudo mkdir movies/vol2
    sudo mkdir movies/vol3
    sudo mkdir myworks
    sudo mkdir transfers
   

4. Add read write support of NTFS using ntfs-3g.
   By default, NTFS read only is supported.

    sudo apt-get update
    sudo apt-get install ntfs-3g
   

5. Find gid, uid of Raspberry Pi user you are using to access the system.
   I am using user id sakthipriyan in this case.

    $ cat /etc/passwd | grep sakthipriyan
    sakthipriyan:x:1001:1001::/home/sakthipriyan:/bin/bash
   

6. Mount each partition to its folder.

    sudo mount -o gid=1001,uid=1001 /dev/sda1 /mnt/storage
    sudo mount -o gid=1001,uid=1001 /dev/sda2 /mnt/movies/vol1
    sudo mount -o gid=1001,uid=1001 /dev/sda3 /mnt/movies/vol2
    sudo mount -o gid=1001,uid=1001,fmask=0022,dmask=0022 /dev/sda5 /mnt/movies/vol3
    sudo mount -o gid=1001,uid=1001,fmask=0022,dmask=0022 /dev/sda6 /mnt/myworks
    sudo mount -o gid=1001,uid=1001,fmask=0022,dmask=0022 /dev/sda7 /mnt/transfers
   

   • All files and folders in FAT32 and NTFS can be owned only at the mount time.
   • gid, uid found in step 5 is used.
   • In case of NTFS partition, by default all files and folders are given permission 777.
   • In order to restrict write access, fmask=0022 and dmask=0022 is used.

7. Check the mounted partitions stats using df -h

    $ df -h
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/root        15G  2.0G   13G  14% /
    devtmpfs        214M     0  214M   0% /dev
    tmpfs           218M     0  218M   0% /dev/shm
    tmpfs           218M  4.4M  213M   3% /run
    tmpfs           5.0M  4.0K  5.0M   1% /run/lock
    tmpfs           218M     0  218M   0% /sys/fs/cgroup
    /dev/mmcblk0p1   60M   20M   41M  34% /boot
    /dev/sda1       200G   53G  148G  27% /mnt/storage
    /dev/sda2       200G  195G  5.2G  98% /mnt/movies/vol1
    /dev/sda3       200G  134G   67G  67% /mnt/movies/vol2
    /dev/sda5       200G   55G  146G  28% /mnt/movies/vol3
    /dev/sda6       100G   35G   66G  35% /mnt/myworks
    /dev/sda7        32G   29G  2.7G  92% /mnt/transfers
   

Or open it from your local machine using nautilus file browser.

    # Replace the IP with actual IP of your Raspberry Pi.
    $ nautilus sftp://192.168.0.10/mnt/

Or access it via any software which supports sftp from any device.

8. Once all work is done with the hard disk, we can unmount the partitions.

    sudo umount /mnt/storage
    sudo umount /mnt/movies/vol1
    sudo umount /mnt/movies/vol2
    sudo umount /mnt/movies/vol3
    sudo umount /mnt/myworks
    sudo umount /mnt/transfers
   

9. Unplug the USB cable from the Raspberry Pi and Power down the external hard disk setup.

Hardware and OS

I was using Raspberry Pi 1 Model B for this setup.
It is running Raspbian GNU/Linux 8 (jessie)

Related

After this set up was done, I benchmarked the file IO performance, here.