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Working with VMs

Parent page: Cloud

A virtual machine (VM) is a virtualized server in the cloud infrastructure. In OpenStack, active virtual machines are referred to as instances. VMs can be managed via the OpenStack dashboard.

Working with VMs

Locking VMs

When working on a project with multiple people or to protect a VM from accidental deletion or shutdown, it can be useful to lock it.

To lock a VM, click on the "Lock Instance" option from the Actions drop-down menu on the dashboard.

Locking instances

Once a VM is locked, most of the Actions menu items will not be able to be executed until the instance is unlocked. There is an icon indicating the lock state for every instance.

To unlock a VM, select the "Unlock Instance" from the Actions drop-down menu on the dashboard.

Resizing VMs

It is possible to resize a VM by changing its flavour. However, there are some things to be aware of when choosing to resize a VM, which depends on whether you have a "p" flavour or a "c" flavour VM (see Virtual machine flavours).

Resizing VMs

Resizing a VM may involve some risk as it is similar to deleting and recreating your VM with a new flavour. If in doubt, contact cloud technical support.

c flavours

"c" flavours often have extra ephemeral drives, which will be resized when you choose a new "c" flavour. These ephemeral drives cannot become smaller, and as such "c" flavour VMs can only be resized to flavours with equal or larger ephemeral drives. After resizing, however, you will not immediately see a larger ephemeral drive within your VM (e.g., the df -h command will not show the size increase). To see this extra space, you will need to resize your filesystem (see the resize2fs command).

Filesystem Resizing

Filesystem resizes should be treated with caution and can take considerable time if the partitions are large. Before resizing a filesystem, it is recommended to create backups of its contents (see backing up your VM).

p flavours

Unlike "c" flavours, "p" flavours do not typically have extra ephemeral drives associated with them, so they can be resized to larger and smaller flavours.