Pelican: A building block for exascale cold data storage

Cold data: data which is rarely read.

Creating a model of a rack and disk i/o to design policies against. Model was verified on the real hardware after design.

Only 8% of disks in a Pelcian rack are allowed to spin at a given moment.

52U rack mounted blob of server, with 1,152 archival drives mounted.

Blocks in a range of 200mb to 1tb are stored.

20 byte identifiers are used to store blocks.

A key-value store tracks where a block is stored given the identifier.

Separates power and cooling domains and restricts which drives can be active at a time based around this.