Hello, >> By the way did you try to test random read performance and latency >> of XIV? Looking into architecture (multiple hosts with 7200rpm SATA >> drives interconnected via 1Gb Ethernet) it should not perform well in >> this area. > > Yes: When I test with fio (6 parallel tasks, aio, direct I/O, depth 256, > 70% reads), the XIV beats the local RAID by a _wide_ margin.
Could you try 1 task, 100% random read? And give us results? :) > I know that the XIV's focus is on parallel I/O, but still: I'm wondering > _where_ in the system the bottleneck appears (knowing that I can get fine > throughput if I run (e.g.) six dd/cat processes in parallel). 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 you can look into alignment issues. If I remember right XIV splits data into 1MB chunks but I don't know what block size is used at lower level. Also you can try to tune read-ahead settings on XIV if that is possible. Mindaugas _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
