I realize I'm a little late to this party but since collectl was mentioned thought I'd jump in. ;) Whenever I do any file system testing I also have a copy of collectl running in another window. Just looking at total transfer times can end up taking you down the wrong path. What is there are long stalls and very burst I/O? could be a starved resource or network issue that has nothing to do with he disks at all. As for iostat, while you're certainly welcome to use it and I based the collectl output display format on it, I'd highly recommend using iostat -x to see wait/service times as those can be key to seeing what's happening. Also, if you use collectl in stead with "-sD --home" you'll basically see the output in a top-like format, making it real easy to see what's happening. Further if you apply the right filter you can simply watch a single disk, line by line w/o any pesky headers in your way. -mark -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
