Backblaze 的 2015 Q3 硬碟故障率報告

依照往例,Backblaze 每一季結束後不久會放出上一季的硬碟故障率報告:「What Can 49,056 Hard Drives Tell Us? Hard Drive Reliability Stats for Q3 2015」。

如果仔細看的話,小硬碟中 Seagate 的死亡率還是很高 (尤其是 ST1500DL003 與 ST3000DM001 這兩顆驚人的數字),而大硬碟 (i.e. 4TB 以上) 都還算合理範圍。

值得提的是,其中 HGST 的硬碟死亡率比起其他家低了不少?

Backblaze 再次發表各家硬碟耐用程度...

今年年初 (一月) 的時候發表過一次「各家硬碟的耐用程度...」引起爭議厚的最新力做,九月再發表一次:「Hard Drive Reliability Update – Sep 2014」。

灰色部份是一月的數據,其他顏色是九月的數據。文中有考慮是否要換成企業級的硬碟 (enterprise drives),但兩個評估的答案是否定的。

第一個評估是成本考量,就算一般硬碟以三年保固期有 15% 的 failure rate,相較於企業級 0% failure rate 計算 (於是直接算成 10 年),成本是不划算的:

Today on Amazon, a Seagate 3 TB “enterprise” drive costs $235 versus a Seagate 3 TB “desktop” drive costs $102. Most of the drives we get have a 3-year warranty, making failures a non-issue from a cost perspective for that period. However, even if there were no warranty, a 15% annual failure rate on the consumer “desktop” drive and a 0% failure rate on the “enterprise” drive, the breakeven would be 10 years, which is longer than we expect to even run the drives for.

更何況企業級硬碟的情況根本沒什麼差:

The assumption that “enterprise” drives would work better than “consumer” drives has not been true in our tests. I analyzed both of these types of drives in our system and found that their failure rates in our environment were very similar — with the “consumer” drives actually being slightly more reliable.

各家硬碟的耐用程度...

最近幾天備份服務 Backblaze 以他們自家使用大量的硬碟統計數字 (快三萬顆硬碟),對硬碟耐用程度發了一篇「What Hard Drive Should I Buy?」的文章。

其實最重要的事情在第一張圖的年故障率就講的差不多了...

另外還有一張三年故障率存活率:

這數字在國外引起不小的風暴啊...