On 05/07/2009, at 1:57 AM, Ross Walker wrote:
Barriers are by default are disabled on ext3 mounts... Google it and you'll see interesting threads in the LKML. Seems there was some serious performance degradation in using them. A lot of decisions in Linux are made in favor of performance over data consistency.
After doing a fair bit of reading about linux and write barriers, I'm sure that it's an issue for traditional direct attach storage and for non-battery backed write cache in raid cards when cache is enabled.
Is it actually an issue if you have a hardware raid controller w/ BBWC enabled and the cache disabled on the HDDs? (i.e. correctly configured for data safety)
Should a correctly performing raid card be ignoring barrier write requests because it is already on stable storage?
cheers, James _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
