Placement engine for a block device

A system comprising:

• one or more virtual machines implemented by a first node in a cluster of nodes;
• and
• a process in communication with each of the one or more virtual machines, the process being executed by the first node and configured to:
• track one or more parameters associated with a plurality of real storage devices (RSDs),
• generate a plurality of RSD objects in a memory associated with the first node, each RSD object corresponding to a particular RSD in the plurality of RSDs,
• generate a virtual storage device (VSD) object in the memory,
• select one or more RSD objects in the plurality of RSD objects based on at least one parameter in the one or more parameters, and
• for each RSD object in the one or more RSD objects, allocate a block of memory in the RSD associated with the RSD object to store data corresponding to a first block of memory associated with the VSD object,
• wherein each RSD object is associated with a failure group identifier that comprises a 32-bit integer that encodes a drive identifier, a node identifier, a rack identifier, and a row identifier.

A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform steps comprising:

• tracking one or more parameters associated with a plurality of real storage devices (RSDs);
• generating a plurality of RSD objects in a memory associated with a first node, each RSD object corresponding to a particular RSD in the plurality of RSDs;
• generating a virtual storage device (VSD) object in the memory;
• selecting one or more RSD objects in the plurality of RSD objects based on at least one parameter in the one or more parameters;
• and
• for each RSD object in the one or more RSD objects, allocating a block of memory in the RSD associated with the RSD object to store data corresponding to a first block of memory associated with the VSD object,
• wherein each RSD object is associated with a failure group identifier that comprises a 32-bit integer that encodes a drive identifier, a node identifier, a rack identifier, and a row identifier.