Volume types

As detailed in the instance creation doc, for storing and processing research data we expect people mount our RDS or HPC scratch storage. This leaves OpenStack volume storage for use as VM disks or specific use cases (e.g. database storage) where larger "local" disks may be preferable to networked storage.

Volume storage is provided by our Ceph cluster and is either backed by HDD (slower) or SSD (faster) drives. Free tier projects will use HDD for their 40GB volume quota and paid projects can choose whether to opt for HDD or SSD, with the latter being highly advisable. Projects that purchase SSD volume quota will have their default volume type set to SSD so in general this distinction will not need to be considered during project configuration.