Hi, I've bought a Xeon based server and I'm trying to see how many IOPS I can get out of it using null_blk driver. Eventually I'll install a NVME SSD card in it.
According to various online documents (see one URL below), I should be getting upwards of 4M IOPS but I'm getting only 2.2. What am I doing wrong here? http://bjorling.me/blkmq-slides.pdf I'm using Centos 7.2 with kernel 3.19.8. Following flags are enabled. CONFIG_POSIX_MQUEUE=y CONFIG_POSIX_MQUEUE_SYSCTL=y CONFIG_SCSI_MQ_DEFAULT=y This is how I load null_blk driver: insmod null_blk.ko submit_queues=48 queue_mode=2 gb=100 bs=4096 nr_devices=1 irqmode=0 completion_nsec=1 hw_queue_depth=128 I'm using fio for the benchmark and here is how I run it: ./fio --filename=/dev/nullb0 --direct=1 --ioengine=libaio --rw=randread --bs=4k --size=200m --numjobs=200 --iodepth=64 --runtime=30 --time_based --group_reporting --name=journal-test The server is Xeon based, here is the output of lscpu: Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 24 On-line CPU(s) list: 0-23 Thread(s) per core: 2 Core(s) per socket: 6 Socket(s): 2 NUMA node(s): 2 Vendor ID: GenuineIntel CPU family: 6 Model: 63 Model name: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz Stepping: 2 CPU MHz: 1299.281 BogoMIPS: 4805.22 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 15360K NUMA node0 CPU(s): 0-5,12-17 NUMA node1 CPU(s): 6-11,18-23 Is there anything I can do to improve the performance? TIA Nisha
