Hello, >> Could you try 1 task, 100% random read? And give us results? :) > > Yes, but I'm not sure which utility to use to create 100% random reads. > Perhaps fio in a 100% read mode?
I used sio_ntap from NetApp. Not bad utility for some simple testing. E-mail me off-list if you would like to get it. >> XIV is the bottleneck. As I already wrote - SAN storage boxes are >> tuned so that they will not give their full power to 1 I/O process. > > But XIV can't see processes on the Linux box. So I reckon it's the > operating system's duty to spread the I/O over the available paths, as > long as there aren't other factors (such as CPU bottlenecks) standing in > the way? This, of course, assumes an active-active(-active)*-situation. Well XIV sees sequential read from the same WWNs. So I believe it can conclude that requests are coming from the same process. > True, its chunks are 1MB. But what would I align? Setting ext3's block > size to 1MB seems like a rather weird idea. Chunks are 1MB but anyway it should use smaller sized blocks. And if it uses 4kb blocks with default Linux partitioning scheme (63 sectors) performance hit can be substancial. Mindaugas _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
