Utilizing mutiple snapshot sources for creating new copy of volume in a networked environment wherein additional snapshot sources are reserved with lower performance levels than a primary snapshot source

Abstract

Aspects relate to techniques for using read-only volume replicas in a distributed computing environment to enable over-subscription on server performance. In order to provide a good customer experience, the I/O handling replicas of a volume are typically reserved at a high percentage of the customer's desired performance. A read-only replica of the volume does not serve user I/O, and can therefore be reserved at a much lower percentage of desired performance. Particularly, as the number of read-only replicas increases, the performance reservation can be lowered due to the statistical likelihood that the server(s) hosting at least one read-only replica will have sufficient performance to support the desired reads during new volume creation (even though that performance has not been fully reserved). Aspects relate to techniques for selecting among read-only replicas to serve reads during creation of a new volume copy.