Tiered data storage in flash memory based on write activity

摘要

A method includes receiving data objects for storage in at least one or more first storage devices characterized by a first write endurance, and one or more second storage devices characterized by a second write endurance that is lower than the first write endurance. Respective write-activity levels are estimated for the data objects. For each data object, a choice is made whether to store the data object in the first storage devices or in the second storage devices based on an estimated write-activity level of the data object. The data object is stored in the chosen storage devices.

主权项

1. A method, comprising:
receiving data objects for storage in at least:
(i) one or more first storage devices characterized by a first write endurance; and(ii) one or more second storage devices characterized by a second write endurance that is lower than the first write endurance; estimating respective write-activity levels for the data objects; and for each data object:
(i) choosing whether to store the data object in the first storage devices or in the second storage devices based on an estimated write-activity level of the data object, and storing the data object in the chosen storage devices; and(ii) storing metadata that is indicative of a storage location of the data object in the first or second storage devices, including, when the data object is stored in the second storage devices, storing authoritative metadata, comprising an authoritative indication that points to the storage location of the data object, and further storing cached-location metadata, comprising a first indication that aims to point to the storage location of the data object, and a second indication that points to the authoritative indication.