Feature #8186
closed[Node Manager] Support (ephemeral) EBS storage for AWS node types that do not have instance storage, like the M4/C4 classes.
Description
Currently node manager only distinguishes between cloud instance types. Enable the admin to specify the amount of additional storage for specific instance types on AWS.
[Size m4.large] cores = 2 scratch = 500
Implementation:
Determine how instance storage is available by default for node type. If additional space is needed, attach an EBS device.
This is configured via ex_blockdevicemappings to libcloud create_node() & documented at https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_BlockDeviceMapping.html
Disks should be VolumeType: 'gp2' (General Purpose SSD), have DeleteOnTermination: true, and specify a VolumeSize: that makes up the difference between instance storage (if any) and the required space.
The compute node boot scripts are expected to discover both instance and EBS storage devices and combine them into a single logical partition / file system. In the above example, after boot time configuration the resulting node should have a single 500 GB file system for scratch space.