Flash Memory Failures in the Field

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A Large-Scale Study of Flash Memory Failures in the Field
This paper presents the first large-scale study of flash-based SSD reliability in the field.

Conclusions:

• We observe that SSDs go through several distinct failure periods – early detection, early failure, usable life, and wearout – during their lifecycle, corresponding to the amount of data written to flash chips.
• We find that the effect of read disturbance errors is not a predominant source of errors in the SSDs we examine.
• Sparse data layout across an SSD’s physical address space (e.g., non-contiguously allocated data) leads to high SSD failure rates; dense data layout (e.g., contiguous data) can also negatively impact reliability under certain conditions, likely due to adversarial access patterns.
• Higher temperatures lead to increased failure rates, but do so most noticeably for SSDs that do not employ throttling techniques.
• The amount of data reported to be written by the system software can overstate the amount of data actually written to flash chips, due to system-level buffering and wear reduction techniques.