On 07/16/2011 06:33 PM, Jeff Janes wrote:
> 2.6 ms for an fsync seems awfully quick. I wonder if EBS uses
> nonvolatile/battery-backed write cache, or if it just lies about fsync
> actually hitting disk.
>
They have the right type of cache in there to make fsync quick, when you
happen to be the lucky one to find it free of a write backlog. So the
best case is much better than a typical spinning drive with no such
cache. The worst case is in the 100ms+ range though on EBS.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD