Re: SSD Drives

On 04/02/2014 02:37 PM, Bret Stern wrote:

> Any opinions/comments on using SSD drives with postgresql?

Using SSDs with PostgreSQL is fine, provided they have an onboard
capacitor to ensure data integrity. The main concern with SSD drives, is
that they essentially lie about their sync status. There is an inherent
race-condition between the time data reaches the drive, and how long it
takes for the write balancing and NVRAM commit overhead.

Most common drives only have a volatile RAM chip that acts as a buffer
space while writes are synced to the physical drive. Without a capacitor
backing, the state of this buffer is erased on power loss, resulting in
a corrupt database.

There are upcoming technologies which may solve this (see ReRAM) but for
now, it's a requirement for any sane system.

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604
312-676-8870
sthomas(at)optionshouse(dot)com

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