On Wed, 2006-02-08 at 14:50 -0600, James Bottomley wrote: > > - How does multipathing affect this (maybe not dm, but others that exist). > > Hey, with block level multi-path that's now officially Someone Else's > Problem. (And it's also a problem for software RAID as well). And actually (in the time honoured tradition of telling someone else what they should be doing while blowing your own trumpet) could I just point out that I think that it's impossible to enforce barriers in the face of multi-path (because of the cross path synchronisation requirements). However, it should be quite easy to enforce linked command ordering in these environments by the simple expedient of tagging a link to a single path. Even on path failure for partial link completion, you simply resend the entire segment of link command set that you don't know completed (because writes are idempotent). James - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
