How to Resize Droplets for Vertical Scaling

Resizing a Droplet changes the resources (CPU, RAM, and disk) that the Droplet has. There are two resizing options for Droplets:

• CPU and RAM only. This option increases or decreases the amount of CPU and RAM available to a Droplet.

• Disk, CPU, and RAM. This option increases or decreases the amount of CPU and RAM available to a Droplet and permanently increases the size of a Droplet’s disk.

Increasing a Droplet’s memory and CPU improves its performance. Increasing the size of its disk increases the amount of data you can store.

You can resize to any Droplet plan that has an equal or greater amount of disk space as the original Droplet.

Considerations Before Resizing

• Allow for about one minute of downtime per GB of used disk space, though the actual time necessary is typically shorter. You can check the disk storage on the filesystem with df / -h.

  Estimated downtime depends on disk usage even for resizes that don’t change the amount of disk space. This is because the Droplet may move to a new hypervisor, which transfers disk data over the network.

• We strongly recommend taking a snapshot of the Droplet before resizing.

  Droplets may change hypervisors during a resize, and any changes to a filesystem can lead to data loss if something goes wrong. We strongly recommend backing up the Droplet’s data before resizing. If you use snapshots, you can delete the snapshot after confirming that the resize was successful.

• You cannot decrease the size of a Droplet’s disk.

  Data is not always sequentially written in memory, so reducing the available space would risk data loss and filesystem corruption. For more flexibility, you can use volumes for additional data storage, which lets you detach or delete the volume if you no longer need the space.

Resizing Droplets with the Control Panel, API, or CLI

You can resize Droplets from the control panel, using the DigitalOcean API, or using doctl, the DigitalOcean CLI.

Using the Control Panel

Before you can resize a Droplet in the control panel, you need to power it off. We recommend you do this from the command line to avoid data corruption, so SSH to your Droplet and issue the shutdown command:

sudo shutdown -h now

Next, go to the DigitalOcean Control Panel. On the Droplets page, click the name of the Droplet you want to resize, then click the Resize option in the Droplet-specific menu.

Alternatively, you can click the Upgrade button next to the Droplet name or at the top of the Droplet detail page, if it is available.

The current Droplet size is highlighted. Choose CPU and RAM only or Disk, CPU, and RAM resizing, then select the new Droplet size. If a plan is unavailable for resizing, the control panel displays the reason.

Once the Droplet is powered down and you’ve chosen its new plan, click Resize. A progress bar displays as the resize takes place.

When the resize event is finished, click the On/Off button to power the Droplet back on.

The new size is visible below the Droplet name. Once the Droplet is booted, you can begin verifying that your services are working as expected. If you took a snapshot of the Droplet before doing the resize, you can now delete the snapshot to avoid further billing for it.

Using the API

When resizing a Droplet via API, you need to specify the resize action type and specify a slug for size. To view a list of slugs, you can use the /v2/size API endpoint.

Resizing via API automatically powers down the Droplet first.

After the resize is complete, power on the Droplet.

Using the CLI

When resizing a Droplet via the CLI, you need to provide a slug to pass to the --size flag. To view a list of slugs, you can use doctl compute size list.

You also need to power off the Droplet by calling doctl compute droplet-action power-off before resizing.

After the resize is complete, power on the Droplet.

Verifying Disk Resizes

In certain cases, a disk resize fails to resize the Droplet’s partition or filesystem. If you rerun df -h after a disk resize and the output is unchanged, this usually indicates a problem. Use gdisk to get more information:

gdisk -l /dev/vda

The output looks like this:

GPT fdisk (gdisk) version 1.0.3
Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present
Found valid GPT with protective MBR; using GPT.
Disk /dev/vda: 104857600 sectors, 50.0 GiB
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): C1E73477-225B-4585-8BB5-C9291E473CE4
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 52428766
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
Number  Start (sector)    End (sector)  Size       Code  Name
   1          227328        52428766   24.9 GiB    8300

Some operating systems, like CentOS, don’t come with gdisk by default. You can either install gdisk using the package manager (for example, sudo yum install gdisk) or use fdisk:

fdisk -l /dev/vda

The output looks like this:

Disk /dev/vda: 50.0 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000b956b

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048    52428766    52426718   83  Linux

In both of the above cases, the partition is still 25 GB even though the disk is 50 GB. To resize the partition, use the growpart command. In this command, /dev/vda is the name of the disk, separated by a space, and followed by the number of the partition to resize, 1.

growpart /dev/vda 1

The command to resize the filesystem depends on the filesystem type. If you don’t know what filesystem you’re using, check with df:

df -Th /dev/vda1

You can see the filesystem type in the second column of the output. The following example output shows the filesystem type is ext4.

Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/vda1      ext4   50G  4.0G   45G  10% /

For ext3/4 filesystems, use resize2fs to resize the filesystem.

resize2fs /dev/vda1

For XFS, use xfs_growfs to resize the filesystem.

xfs_growfs /dev/vda1

If there is more than one partition on the disk, you may have to modify the above commands to more closely match the Droplet’s partition table. Partitions are numbered, so if you want to grow a specific partition, use its number in the growpart /dev/vda command. For example, growpart /dev/vda 2 grows the second partition.