18.05.2010 23:37, Stefan Hajnoczi wrote:
I just caught up on mails and saw you had already mentioned that overlapping writes from the guest look fishy in the "the>1Tb block issue". Cache mode might still be interesting because it affects how guest virtio-blk chooses queue ordering mode.
What I can say for sure is that the issue mentioned (>1Tb block) occurs regardless of the cache mode. I tried all 3, with exactly the same results (well, not entirely exactly, since the prob depends on timing too, and timing is different depending on the cache mode), and performed all further tests with cache=writeback since it's the mode which lets the guest to finish mkfs'ing the 1.5Tb "disk" in a reasonable time (or else it takes hours). But actually I don't quite see where that dependency is: guest does not know how its data is cached on host... /mjt -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
