Running basic applications on the cloud
A common use case is to simply use your instance on the cloud to run applications.
To do this you will need to know:
- The applications licencing terms (some companies have very different licences for running on the cloud);
- How to install and configure the required applications on your instances;
- How to move data to and from your instances;
- How to make data available to the applications on the instances.
Volume storage is analogous to a USB drive: you attach it to your running instance, then detach it before you delete the instance. In this way, your data can live on beyond the life of your instances.
One limitation to be aware of is that a Volume can only be connected to a single running instance at a time.
If you decide you need Volume storage, remember to include it in your project allocation request.
Stopping your instances
When you are finished using your applications you should remember to destroy your instances.
There are several different ways of stopping your running instance:
- A paused instance is simply halted in memory, ready to be started again.
- A stopped instance has its state written to the host disk, ready to be resumed from there.
- A soft reboot tries to do a graceful reboot (you ask the OS to reboot).
- A hard reboot forcibly reboots the instance! (you press the reset button)
- A shut off instance is one that has been gracefully powered down.
- A deleted instance is one that has been forcibly terminated and all traces removed from the host.
NB Know that if you don't delete your instance then it will still be counted against your allocation. Stopped and paused instances are still consuming resources on their host!
There are two types of snapshots you can make:
- An instance snapshot.
- A volume snapshot.
There are certain similarities between them, although there are also important differences. They both create a copy of the current state of an instance or snapshot respectively. Your instance snapshots appear in the dashboard under the Compute -> Images tab. Volume snapshots are under Volumes -> Snapshots.
You can use an instance snapshot as a template when launching a new instance. You can use a volume snapshot to create a new volume. It will be identical to how the original volume was at the time of the snapshot.
It is possible to convert an instance snapshot into a volume via the entries in Compute -> Images. This could be useful if you want a boot-from-volume instance based on one of your instance snapshots.
N.B. If you make a snapshot of a running instance, you will only copy the primary disk, not any attached volume storage.
Moving data to and from your instance
There are many applications you can use to move data to and from your instance. Some common ones are:
- rsync - a unix command line utility for transferring and synchronising files across computer systems;
- sftp - a command line file transfer program that uses the SSH connection to transfer the files;
- scp - secure copy, another command line utility that uses the SSH connection to transfer the files;
- Cyberduck, FileZilla - programs with a graphical user interface. They run on both Windows and macOS. WinSCP is an easy to use Windows only program.
- database backup/restore - if your application has a relational database, the chances are good that the database supports backing up and restoring of its contents.
- application import/export utilities - a lot of applications support the export/import of data directly, either via their user interface or programmatically. Be wary of data uploads through the web - they will often be very slow compared to other methods listed.
The best path here is entirely dependent on your applications and the way in which you are using them. We have basic walk-throughs in the file transfers guide.
If you have technical questions, or would like to discuss your needs with us, you may request help or further hands on training here:
Alternatively you may contact us at firstname.lastname@example.org.