Mounting Amazon EC2 Volume

This is a repost from: Making an Amazon F Volume Available For Use

  1. Connect to your instance using SSH.
  2. Depending on the block device driver of your instance’s kernel, the device may be attached with a different name than what you specify. For example, if you specify a device name of /dev/sdh, your device may be renamed /dev/xvdh or /dev/hdh by the kernel; in some cases, even the trailing letter may also change (where /dev/sda could become/dev/xvde). Amazon Linux AMIs create a symbolic link from the renamed device path to the name you specify, but other AMIs may behave differently.Use the lsblk command to view your available disk devices and their mount points (if applicable) to help you determine the correct device name to use.
    [ec2-user ~]$ lsblk
    xvdf  202:80   0  100G  0 disk
    xvda1 202:1    0    8G  0 disk /

    The output of lsblk removes the /dev/ prefix from full device paths. In this example, /dev/xvda1 is mounted as the root device (note the MOUNTPOINT is listed as /, the root of the Linux file system hierarchy), and /dev/xvdf is attached, but it has not been mounted yet.

  3. Determine if you need to create a file system on the volume. New volumes are raw block devices, and you need to create a file system on them before you can mount and use them. Volumes that have been restored from snapshots likely have a file system on them already; if you create a new file system on top of an existing file system, the operation overwrites your data. Use the sudo file -s device command to list special information, such as file system type.
    [ec2-user ~]$ sudo file -s /dev/xvdf
    /dev/xvdf: data

    If the output of the previous command shows simply data for the device, then there is no file system on the device and you need to create one. You can go on to Step 4. If you run this command on a device that contains a file system, then your output will be different.

    [ec2-user ~]$ sudo file -s /dev/xvda1
    /dev/xvda1: Linux rev 1.0 ext4 filesystem data, UUID=1701d228-e1bd-4094-a14c-8c64d6819362 (needs journal recovery) (extents) (large files) (huge files)

    In the above example, the device contains Linux rev 1.0 ext4 filesystem data, so this volume does not need a file system created (you can skip Step 4 if your output shows file system data).

  4. (Optional) Use the following command to create an ext4 file system on the volume. Substitute the device name (such as /dev/xvdf) for device_name. Depending on the requirements of your application or the limitations of your operating system, you may opt for a different file system type, such as ext3 or XFS.


    This step assumes that you’re mounting an empty volume. If you’re mounting a volume that already has data on it (for example, a volume that was restored from a snapshot), don’t use mkfs before mounting the volume (skip to the next step instead). Otherwise, you’ll format the volume and delete the existing data.

    [ec2-user ~]$ sudo mkfs -t ext4 device_name
  5. Use the following command to create a mount point directory for the volume. The mount point is where the volume is located in the file system tree and where you read and write files to after you mount the volume. Substitute a location for mount_point, such as /data.
    [ec2-user ~]$ sudo mkdir mount_point
  6. Use the following command to mount the volume at the location you just created.
    [ec2-user ~]$ sudo mount device_name mount_point
  7. (Optional) To mount this Amazon EBS volume on every system reboot, add an entry for the device to the /etc/fstab file.
    1. Create a backup of your /etc/fstab file that you can use if you accidentally destroy or delete this file while you are editing it.
      [ec2-user ~]$ sudo cp /etc/fstab /etc/fstab.orig
    2. Open the /etc/fstab file using your favorite text editor, such as nano or vim.
    3. Add a new line to the end of the file for your volume using the following format.
      device_name  mount_point  file_system_type  fs_mntops  fs_freq  fs_passno

      The last three fields on this line are the file system mount options, the dump frequency of the file system, and the order of file system checks done at boot time. If you don’t know what these values should be, then use the values in the example below for them (defaults 0 2). For more information on /etc/fstab entries, see thefstab manual page (by entering man fstab on the command line). For example, to mount the ext4 file system on the device /dev/xvdf at the mount point /data, add the following entry to /etc/fstab.

      /dev/xvdf       /data   ext4    defaults        0       2
    4. After you’ve added the new entry to /etc/fstab, you need to check that your entry works. Run the sudo mount -a command to mount all file systems in /etc/fstab.
      [ec2-user ~]$ sudo mount -a

      If the above command does not produce an error, then your /etc/fstab file is OK and your file system will mount automatically at the next boot. If the command does produce any errors, examine the errors and try to correct your /etc/fstab.


      Errors in the /etc/fstab file can render a system unbootable. Do not shut down a system that has errors in the /etc/fstab file.

    5. (Optional) If you are unsure how to correct /etc/fstab errors, you can always restore your backup /etc/fstab file with the following command.
      [ec2-user ~]$ sudo mv /etc/fstab.orig /etc/fstab