On Mon, Aug 6, 2012 at 2:15 PM, Stefan Ring <stefan...@gmail.com> wrote: > So you're saying that SSDs don't generally flush data to stable medium > when instructed to? So data written before an fsync is not guaranteed > to be seen after a power-down?
It depends on the model. Consumer models are less likely to immediately flush. My understanding that this is done in part to do some write coalescing and reduce the number of P/E cycles. Enterprise models should either flush, or contain a super capacitor that provides enough power for the drive to complete writing any date in its buffer. > If that -- ignoring cache flush requests -- is the whole reason why > SSDs are so fast, I'm glad I haven't got one yet. They're fast for random reads and writes because they don't have seek latency. They're fast for sequential IO because they aren't limited by spindle speed. -- Brandon High : bh...@freaks.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
