If you already have a server image that you would like to use on top of UpCloud’s IaaS service, you can create a bootable OS storage from it. The process requires that you deploy a new server, upload the image to the cloud host and set up the new disk device. This guide goes through the process step-by-step.

Deploying a new host

Begin by log into your UpCloud control panel. Deploying a Linux based cloud server of your choosing with two storages devices. The first storage will be the regular operating system disk, with enough empty space to upload your own server image file. The second storage should be an empty device with the capacity you wish, same or larger than the server image. Consider the following when making the configurations:

  • Set your server’s hostname as the Server Name at the deployment and write a short description of the image.
  • Select the zone to where you wish to upload the server image. The geographical zone close to you will allow faster upload.
  • Select the system resources, these can always be changed later.
  • Add a secondary disk and set the sizes for the storage devices. The first disk needs enough space to download the system image and the second at least the same size as the system you are migrating.

Once you have made the selections, click the Deploy server button. Wait a few seconds for the server to start, then login to the newly deployed host to continue.

Update the system to make sure the software is running the latest version.

# Debian and Ubuntu
sudo apt-get update && sudo apt-get dist-upgrade -y
# CentOS
sudo yum update -y

With the new server up to date, check that both of the storage drives are attached and report their size correctly.

vda    253:0    0  25G  0 disk
└─vda1 253:1    0  25G  0 part /
vdb    253:16   0  25G  0 disk

Here the vda disk with a partition called vda1 is your primary storage and the vdb disk as the secondary device without partitions. If everything seems in order, continue with uploading your server image to the cloud host.

Importing the system image

When the new host is up and ready, upload your server image, for example using Secure Copy, SFTP or rsync.

You can find out about some of the different secure file transfer options in the first section for Encrypt communications in the guide for cloud server security. Depending on your original system and your network connection it may be useful to compress the disk files for the transfer and then uncompress again on the target host.

When you have uploaded the image to the server, you will need to copy the image content to the empty storage device. Use the following command while replacing the <server image> with the system image file, the target disk is usually located at /dev/vdb.

dd if=<server image> of=/dev/vdb bs=16M oflag=direct

Note that the server image needs to be in RAW format ending with the .img file extension. This means images taken, for example, from a VMware-environment do not work as is. The VMware images should be converted to the RAW format with a tool such as qemu-img, which is available for install on most package managers. Check out our guide about how to import VMware image to UpCloud to learn more.

Afterwards, you can shut down the server and remove the old primary disk. Go to your UpCloud control panel and select the Disks tab under Server settings. Once the server has shut down, click the Detach button on the primary disk to remove it. The second disk, where you just transferred the system image, will then be automatically set as the new primary disk. In the same menu, you should also choose the disk controller. VirtIO controller provides the best performance, but if you have issues starting the server, try IDE as it has better compatibility with different operating systems.

You can then restart the server again to continue configuring the system.

Reconfiguring the new host

The newly transferred operating system should now boot up to the cloud server. However, depending on your old network setting you may need to log in using the Web Console to fix any issues before the system will connect normally. Go to your UpCloud control panel then select the Console tab under your Server settings and click Open the console connection.

Log in normally with the user credentials for the server image as before transferring it to the cloud. Once in, check the network settings with the following command.

ip addr

UpCloud hosts have three network interfaces in the default configuration, public IPv4, private IPv4 and public IPv6 addresses. You might see something similar to the example output below. The first interface eth0 might work but the other devices are not yet configured.

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
 inet scope host lo
 valid_lft forever preferred_lft forever
 inet6 ::1/128 scope host
 valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
 link/ether 6e:d7:1b:bf:18:29 brd ff:ff:ff:ff:ff:ff
 inet brd scope global eth0
 valid_lft forever preferred_lft forever
 inet6 fe80::6cd7:1bff:febf:1829/64 scope link
 valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
 link/ether 6e:d7:1b:bf:e6:f2 brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
 link/ether 6e:d7:1b:bf:61:a8 brd ff:ff:ff:ff:ff:ff

Edit your network configuration files to match the network interface names listed in the above output. For example on Ubuntu and other Debian-based systems use the command below to open the configuration file.

sudo nano /etc/network/interfaces

Add the following sections to the file. If the network interfaces were named differently, use those names instead of eth0, eth1, etc.

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

auto eth1
iface eth1 inet dhcp

auto eth2
iface eth2 inet6 auto

On CentOS and other Red Hat variants, the network interfaces are configured in individual files. These files are stored in the /etc/sysconfig/network-scripts/ directory, check the file names with the command below.

ls /etc/sysconfig/network-scripts/ | grep ifcfg-

Then open the first interface file for edit, for example, ifcfg-eth0.

sudo vi /etc/sysconfig/network-scripts/ifcfg-eth0

The file should read at least the following settings. In case, ONBOOT is set to no, change it to yes and save the file.


You may need to do the same operation to other network interfaces, or simply create new configuration files if your old system only had one or two interfaces.

Afterwards, reboot the server and try logging in with SSH. If the network is working you can start using the new host as before with the added benefit of the freely scalable system resources and faster than SSD storage disks with MaxIOPS technology.

Final steps

Congratulations, your own server image should now be up and running on a brand new cloud host. In case you have any further problems with the network, you can find additional help with troubleshooting the connectivity at the guide for network issues with Linux host.

If you run into issues with booting from the new system image, you can always attach the old primary disk again and find the image files safely stored for another try without the need to wait for the image to upload again. Once you are confident that the new system is running properly, you can go to the Disks menu at your UpCloud control panel and delete the unnecessary storage device.