Amazon Elastic Compute Cloud
User Guide for Linux (API Version 2014-10-01)
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Expanding the Storage Space of a Volume

Sometimes, you might need to increase the storage space of an existing volume without losing the data that is on the volume. You can expand the storage space of an Amazon EBS volume by migrating your data to a larger volume and then extending the file system on the volume to recognize the newly-available space. After you verify that your new volume is working properly, you can delete the old volume.

If you need to expand the storage space of a volume on a Windows instance, see Expanding the Storage Space of a Volume in the Amazon EC2 User Guide for Microsoft Windows Instances.

Migrating Your Data to a Larger Volume

To migrate your data to a larger Amazon EBS volume

  1. Open the Amazon EC2 console.

  2. Ensure that the instance's Shutdown Behavior value is set to Stop and not Terminate. If it is already set to Stop, go on to step 3.

    1. In the navigation pane, click Instances, right-click on the instance to check, select Instance Settings, and then select Change Shutdown Behavior.

    2. If the Shutdown behavior is set to Terminate, select Stop from the list and click Apply.

      If the Shutdown behavior is set to Stop, click Cancel.

      Change Shutdown Behavior dialog box
  3. Stop the instance. For more information about how to stop an instance, see Stopping and Starting Your Instances.

  4. Create a snapshot of the volume to expand.

    1. In the navigation pane, click Volumes, right-click on the volume to be expanded, and select Create Snapshot.

    2. Enter a Name and Description for the snapshot, and click Yes, Create.

  5. Create a new volume from the snapshot.

    1. In the navigation pane, click Snapshots.

    2. When the status of the snapshot that you just created is set to completed, select the snapshot and click Create Volume.

      Note

      It can take several minutes for the snapshot to complete.

    3. In the Create Volume dialog box, select the desired volume type, enter the new size for the volume, set the Availability Zone to the same Availability Zone as the instance, and click Yes, Create.

  6. Detach the old volume.

    1. In the navigation pane, click Volumes, select the old volume from the list of volumes, and make note of the value of device name in Attachment information. The attachment information value takes the following form:

      instance information:device name
    2. Right-click the old volume and select Detach Volume.

    3. In the Detach Volume dialog box, click Yes, Detach. It may take several minutes for the volume to be detached.

  7. Attach the newly expanded volume

    1. In the navigation pane, click Volumes, select the new volume from the list of volumes, right-click the new volume, and select Attach Volume.

    2. Start typing the name or ID of the instance in the Instance field, select the instance, enter the same device name retrieved in Step 6.a, and click Yes, Attach.

  8. Restart the instance.

    1. In the navigation pane, click Instances, right-click the instance, select Instance State, and select Start.

    2. In the Start Instances dialog box, select Yes, Start. If the instance fails to start, and the volume being expanded is a root volume, verify that you attached the expanded volume using the same device name as the original volume (root volumes must be attached as /dev/sda1).

      Important

      Only EC2-VPC instances with Elastic IP addresses retain their public IP address when they are stopped. If your instance is running in EC2-Classic, the EIP address is disassociated when the instance is stopped, and you must re-associate the EIP after restarting the instance. For more information, see Elastic IP Addresses (EIP). If your instance is not using an EIP, then you need to retrieve your new public DNS name for your instance from the Instances page of the Amazon EC2 console to connect to it.

After the instance has started, you can check the file system size to see if your instance recognizes the larger volume space. On Linux, use the df -h command to check the file system size.

[ec2-user ~]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/xvda1            7.9G  943M  6.9G  12% /
tmpfs                 1.9G     0  1.9G   0% /dev/shm

If the size does not reflect your newly-expanded volume, you must extend the file system your device so that your instance can use the new space. For more information, see Extending a Linux File System.

Extending a Linux File System

In Linux, you use a file system-specific command to resize the file system to the larger size of the new volume. This command works even if the volume you wish to extend is the root volume. For ext2, ext3, and ext4 file systems, this command is resize2fs. For XFS file systems, this command is xfs_growfs. For other file systems, refer to the specific documentation for those file systems for instructions on extending them.

If you are unsure of which file system you are using, you can use the file -s command to list the file system data for a device. The following example shows a Linux ext4 file system and an SGI XFS file system.

[ec2-user ~]$ sudo file -s /dev/xvd*
/dev/xvda1: Linux rev 1.0 ext4 filesystem data ...
/dev/xvdf:  SGI XFS filesystem data ...

Note

If the volume you are extending has been partitioned, you need to increase the size of the partition before you can resize the file system. For more information, see Expanding a Linux Partition.

To check if your volume partition needs resizing

  • Use the lsblk command to list the block devices attached to your instance. The example below shows three volumes: /dev/xvda, /dev/xvdb, and /dev/xvdf.

    [ec2-user ~]$ lsblk
    NAME    MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
    xvda    202:0    0  30G  0 disk
    └─xvda1 202:1    0  30G  0 part /
    xvdb    202:16   0  30G  0 disk /mnt
    xvdf    202:80   0  35G  0 disk
    └─xvdf1 202:81   0   8G  0 part

    The root volume, /dev/xvda1, is a partition on /dev/xvda. Notice that they are both 30 GiB in size. In this case, the partition occupies all of the room on the device, so it does not need resizing.

    The volume /dev/xvdb is not partitioned at all, so it does not need resizing.

    However, /dev/xvdf1 is an 8 GiB partition on a 35 GiB device and there are no other partitions on the volume. In this case, the partition must be resized in order to use the remaining space on the volume. For more information, see Expanding a Linux Partition. After you resize the partition, you can follow the next procedure to extend the file system to occupy all of the space on the partition.

To extend a Linux file system

  1. Log in to your Linux instance using an SSH client. For more information about connecting to a Linux instance, see Connecting to Your Linux Instance Using SSH.

  2. Use the df -h command to report the existing file system disk space usage. In this example, the /dev/xvda1 device has already been expanded to 70 GiB, but the ext4 file system only sees the original 8 GiB size, and the /dev/xvdf device has been expanded to 100 GiB, but the XFS file system only sees the original 1 GiB size.

    [ec2-user ~]$ df -h
    Filesystem            Size  Used Avail Use% Mounted on
    /dev/xvda1            7.9G  943M  6.9G  12% /
    tmpfs                 1.9G     0  1.9G   0% /dev/shm
    /dev/xvdf            1014M   33M  982M   4% /mnt
  3. Use the file system-specific command to resize the file system to the new size of the volume. For a Linux ext2, ext3, or ext4 file system, use the following command, substituting the device name that you want to extend.

    [ec2-user ~]$ sudo resize2fs /dev/xvda1
    resize2fs 1.42.3 (14-May-2012)
    Filesystem at /dev/xvda1 is mounted on /; on-line resizing required
    old_desc_blocks = 1, new_desc_blocks = 5
    Performing an on-line resize of /dev/xvda1 to 18350080 (4k) blocks.
    The filesystem on /dev/xvda1 is now 18350080 blocks long.

    For an XFS file system, use the following command, substituting the mount point of the file system (XFS file systems must be mounted to resize them).

    [ec2-user ~]$ sudo xfs_growfs -d /mnt
    meta-data=/dev/xvdf              isize=256    agcount=4, agsize=65536 blks
             =                       sectsz=512   attr=2
    data     =                       bsize=4096   blocks=262144, imaxpct=25
             =                       sunit=0      swidth=0 blks
    naming   =version 2              bsize=4096   ascii-ci=0
    log      =internal               bsize=4096   blocks=2560, version=2
             =                       sectsz=512   sunit=0 blks, lazy-count=1
    realtime =none                   extsz=4096   blocks=0, rtextents=0
    data blocks changed from 262144 to 26214400

    Note

    If you receive an xfsctl failed: Cannot allocate memory error, you may need to update the Linux kernel on your instance. For more information, refer to your specific operating system documentation.

  4. Use the df -h command to report the existing file system disk space usage, which should now show the full 70 GiB on the ext4 file system and 100 GiB on the XFS file system.

    # df -h
    Filesystem            Size  Used Avail Use% Mounted on
    /dev/xvda1             69G  951M   68G   2% /
    tmpfs                 1.9G     0  1.9G   0% /dev/shm
    /dev/xvdf             100G   45M  100G   1% /mnt

Deleting the Old Volume

After the new volume has been attached and extended in the instance, you can delete the old volume if it is no longer needed.

To delete the old volume

  1. In the Amazon EC2 console, click Volumes in the navigation pane.

  2. Right-click the old volume and select Delete Volume.

  3. In the Delete Volume dialog box, click Yes, Delete.