Feature #8186
Updated by Peter Amstutz almost 7 years ago
Design sketch.
Currently node manager only distinguishes between cloud VM sizes. A given VM type with additional storage probably needs to be treated as a distinct "size" within node manager. Currently it uses the cloud size id, so this means each "size" will need to be given an ID for use by node which is distinct from the cloud size id.
At least initially, it will probably be easier if the additional sizes are defined in the node manager configuration (instead of generated on the fly). One could, for example, specify a 2 core node with default storage, and a second configuration based on the same VM type with an additional 400 GB of storage. For example:
<pre>
[Size m4.large]
cores = 2
scratch = 100 # default storage
[Size m4.large_extra_storage]
type = m4.large
cores = 2
scratch = 100 # default storage
additional_storage = 400 # storage to attach
</pre>
The compute node boot scripts will discover both default and additional attached storage devices and combine them into a single logical partition / file system. In the above example, after boot time configuration the resulting node would have a single 500 GB file system for scratch space.
When creating the node, the cloud driver will be responsible for attaching the additional disks and then ensuring that they are deleted when the node is deleted.