On Tue, October 13, 2009 12:33 pm, Christoph Hellwig wrote: > On Mon, Oct 12, 2009 at 05:58:20PM +0100, mark delfman wrote: >> Hi... in recent tests we are seeing a 50% drop in performance from >> XFS>MD on a 2.6.30 kernel (compared to a 2.6.28 kernel) >> >> In short: Performance to MD0 direct = circa 1.7GBsec (see below), via >> xfs circa 850MBsec. On previous system (2.6.28) there was no drop in >> performance (in fact often an increase). >> >> I am hopefully that this is simply a matter of barriers etc on the >> newer kernel and MD, but we have tried many options and nothing seems >> to change this so would very much appreciate advice. > > Did barrier support for RAID0 got introduced in 2.6.30? No, though it is due to go in for 2.6.33 NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
