On Fri, Apr 06, 2012 at 02:47:32AM -0400, Robin Humble wrote:
what about sector re-writes - have you seen ZFS do any of those? I presume ZFS does this, but again, I haven't seen it yet in my testing.
i've seen resilvering in tests where i've yanked a drive from a vdev, written data, and then put it back in. i've also seen the same when i've corrupted one of the disks in a VMs vdev by writing to it from the host OS and then either try to cause the VM to read that data or run zfs scrub on the pool. also, one of my home pools is mostly made up of WD Green drives, so i've also occasionally seen rewrites when the long timeouts cause zfs to decide that the block is bad. whether the sector(s) actually got remapped by the drive is hard to tell. i'd assume so.
how's lustre looking?
improving. it's quite an 'experimental' lustre version that they're using, even without the ZFS additions, so lots of new and shiny things to break! :) https://github.com/chaos/lustre/tags unfortunately the zfs backend usually still deadlocks when I push it hard :-/ md backend is ok.
any idea what's causing the deadlocks? only when writing, or reading too? random or sequential writes?
I suspect we should know more after LUG in a few weeks time http://www.opensfs.org/lug/program
judging by their hw config and my benchmarks (and assuming it's the same config as in Brian's talk at LUG last year) I think they'll easily get to their target of 1TB/s write, but 1TB/s reads will be a bit harder. I suspect they'll still get there though.
cool, i'll keep an eye out for that. I definitely want to read his presentation or watch it if ends up on youtube or somewhere. craig -- craig sanders <cas@taz.net.au> BOFH excuse #14: sounds like a Windows problem, try calling Microsoft support