Am 30.10.2011 21:59, schrieb Richard W.M. Jones: >> I've pulled most of the information you requested. See above. I >> don't see any specific cache settings on either machine. Is there >> somewhere I would see the default setting on the machine? > > I'm out of the loop on what the default caching policy is these days. > Hopefully libvirt is at least choosing a safe one.
cache=writethrough is the default. And indeed this is the safest option, and at the same time by far the slowest option. I would expect that you get much better write performance with cache=none. Note however that older guests OSes cannot deal correctly with disks that have a volatile write cache, like cache=none emulates. This means that in case of a host crash and with some bad luck, your guest might experience file system corruption. Recent guest OSes are safe in this respect and can be used with cache=none or cache=writeback in order to improve performance without any such risk. Kevin _______________________________________________ virt mailing list [email protected] https://admin.fedoraproject.org/mailman/listinfo/virt
