SSD Drives Ignore Disk Flushes

A lot of desktop-grade SSD drives can ignore disk flushes and fool operating systems by reporting that data was written while it was actually not. Examples of such drives are OCZ Vertex 3 and Intel X25-E, X-25-M G2 that are known to be unsafe on data commits. Such disk drives should not be used with databases and may easily corrupt the file system on a power failure.

The 3rd generation Intel SSD drives (S3700 and 710 series) do not have these problems, featuring a capacitor to provide a battery backup for flushing the drive cache when the power goes out.

Use SSD drives with care and only when you are sure that drives are server-grade drives and obey "flush" rules. For more information on this issue, read the following article about PostreSQL: http://www.postgresql.org/docs/current/static/wal-reliability.html.