On 5/16/13 8:06 PM, Tomas Vondra wrote:
Have you considered using a UPS? That would make the SSDs about as reliable as SATA/SAS drives - the UPS may fail, but so may a BBU unit on the SAS controller.
That's not true at all. Any decent RAID controller will have an option to stop write-back caching when the battery is bad. Things will slow badly when that happens, but there is zero data risk from a short-term BBU failure. The only serious risk with a good BBU setup are that you'll have a power failure lasting so long that the battery runs down before the cache can be flushed to disk.
-- Greg Smith 2ndQuadrant US greg@xxxxxxxxxxxxxxx Baltimore, MD PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
