Etsy 用 SSD 的故事

Etsy 的 Laurie Denness 對於 Etsy 使用各種品牌 SSD 的情況給出了他的經歷：「SSDs: A gift and a curse」。

重點在於開頭說的：

SSD firmware is buggy

可以看到當 SSD 配上 RAID controller 的時候，常常會需要找問題... (而且很難找)

Intel 的評價很不錯：

Okay, bad start, we’ve actually had no issues with Intel. This seems to be common across other companies we’ve spoken to.

OCZ 倒了，被 Toshiba 收購，而且 S.M.A.R.T. 資訊很差，很難預測什麼時候會掛掉 (有助於提前替換)：

However, they had poor SMART info (none) so predicting failures was hard.

HP 是個大黑盒：

Unfortunately, HP have proprietary RAID controllers, and they don’t support SMART. Or rather, they refuse to talk to non-HP drives using off the shelf technology, they have their own methods.

Samsung 的評價不錯，C/P 值很高，而且有 S.M.A.R.T.：

Samsung saved the day and picked up from OCZ with a ludicrously cheap 960GB offering, the 840 EVO. A consumer drive, so very limited warranty, but for the price (~$400-500) you got great IOPS and they were reliable. They had better SMART info, and seemed to play nicely with our hardware.

不過 BB6Q 版的韌體搞爆了效能，雖然最後修好了：「Samsung Releases Firmware Update to Fix the SSD 840 EVO Read Performance Bug」。

而 LiteOn 則是掛在 GC 上 (RAID 裡同時掛掉兩顆以上)：

The SSDs were having extended garbage collection periods, exacerbated by a smaller amount of SSDs with higher IO, in RAID6. This caused the controller to kick the drive out of the array… and unfortunately due to the write levelling across the drives, at least two of them were garbage collecting at the same time, destroying the array integrity.

不過後來 Dell 與 LiteOn 分別就 RAID controller 與 SSD 本身都跳下去修正，最後還是解決了：

Dell and LiteOn together identified and fixed weaknesses in their RAID controller, the backplane and the SSD firmware.

算是經驗分享，在 SSD 硬碟成熟的過程中間必經的道路 XD