Frequently Asked Questions

How to boot a server from a volume?

Create a bootable volume from an image

openstack volume create --image="IMAGE" --size="SIZE" "DEMO_ROOT"

Create a new instance

openstack server create "DEMO" --flavor="FLAVOR" --volume="DEMO_ROOT" --network="NETWORK" --key-name "KEY"

How to get a larger root disk for my server?

Yes. By default instances get a 25G root disk. If you need more space on your root drive boot from a volume. Below are the necessary steps for two cases: if you need more space on an existing instance or know that the server you are about to boot will need more room.

This will guide you through the process of creating a volume from your running instance, then recreating the instance based on that volume. Suppose I have a server named DEMO. It was booted using the standard 25G root disk provided for all instances.

Steps:

Stop the server
```
openstack server stop "DEMO"
```

Once the state has reached SHUTOFF, make a snapshot

openstack server image create "DEMO" --name="DEMO_SNAP" --wait

Create a volume from the snapshot image:

openstack volume create --image="DEMO_SNAP" --size="SIZE" "DEMO_ROOT"

Delete the old instance
```
openstack server delete "DEMO"
```

Create a new instance

openstack server create "DEMO" --flavor=FLAVOR --volume="DEMO_ROOT" --network=NETWORK

How to live resize a volume?

In the future you can grow the volume like this:

openstack --os-volume-api-version 3.42 volume set "DEMO_ROOT" --size 

Then you need to grow the partition and filesystem on the server, for example if this was the root disk of your server:

growpart /dev/vda 1
resize2fs /dev/vda1