TECHNICAL FIELD

This disclosure relates generally to storage systems and, more specifically, to techniques for managing solid-state storage systems.

BACKGROUND

The advent of non-volatile solid-state storage such as NAND-flash storage has been a driving force in the state-of-the-art development of high-performance data storage systems. As compared to hard disk drives with rotating platters and mechanically moving components, data storage systems that implement non-volatile solid-state storage have more optimal operating characteristics such as lower power consumption, higher input/output performance, better random I/O performance, etc. However, non-volatile solid-state storage media have a limited endurance and lifetime due to the fact that the memory cells of solid-state storage media gradually wear out over time as a result of slight physical wear that is caused by each program/erase (P/E) cycle of the memory cells. The process of writing data to a solid-state storage device is referred to as program (P), and the process of erasing data from the solid-state storage device is called erase (E), wherein stored data in a memory cell must be erased before new data can be programmed to the memory cell. As such, there is finite life expectancy of a solid-state storage device as a result of the limited number of P/E cycles that the memory cells of the solid-state storage device can withstand before the capability of the memory cells to reliably storage electrical charge is degraded to a point at which the solid-state storage device becomes unstable or unusable.

The endurance of a solid-state storage device is typically quantified by a manufacturer specification referred to as Drive Writes Per Day (DWPD). More specifically, for a solid-state drive (SSD), the DWPD value provides a measure of how many times the entire capacity of the SSD can be written/overwritten per day over a warranty period (i.e., expected lifespan). By way of example, an SSD may have a rated endurance of one (1) DWPD over 5 years. Many types of data storage systems which implement solid-state storage (e.g., enterprise and cloud data storage systems) provide data storage services to many different clients, wherein the clients can have different write loads which can vary over time. For example, there could be periods (e.g., weeks, months, etc.) in which the data storage system has an intensive write load (4 drive writes per day), as well as periods with small write loads (e.g., less than 1 drive writes per day). If the actual DWPD of the solid-state storage is greater, on average, than the manufacture-specified DWPD value, the solid-state storage may wear out more quickly and reduce the lifespan of the solid-state storage below the manufacture-specified lifespan.

SUMMARY

Exemplary embodiments of the disclosure include techniques for automated adaptive endurance tuning of solid-state storage media. For example, an exemplary embodiment includes a method that is performed by a storage control system. The storage control system tracks usage metrics associated with utilization of solid-state storage devices of a storage system, wherein the storage system comprises an amount of over-provisioned capacity allocated in the solid-state storage devices according to an over-provisioning factor. The storage control system determines a current endurance value of the data storage system based at least in part on the usage metrics. The storage control system compares the current endurance value to a target endurance value to determine if the current endurance value differs from the target endurance value. The storage control system automatically adjusts the over-provisioning factor in response to determining a difference between the current endurance value and the target endurance value. The storage control system automatically adjusts the amount of over-provisioned capacity allocated in the solid-state storage devices according to the adjusted over-provisioning factor.

Other embodiments of the disclosure include, without limitation, systems and articles of manufacture comprising processor-readable storage media, which are configured to provide automated adaptive endurance tuning of solid-state storage media.

