The following document gives some ideas on how to benchmark an installation with regard to the GlusterFS storage backend.
For most of the benchmarks, the excellent fio tool will be used. At least version 2.1.11 of fio is required for gfapi (and O_DIRECT) support.
The options for fio are mostly taken from http://www.storagereview.com/fio_flexible_i_o_tester_synthetic_benchmark
FUSE mount
The following commandline creates a file fio.test with the size of 256MB, opened using O_DIRECT and simulates a random read/write load where 70% are read operations.
The options refill_buffers are supposed to make the workload more realistic in the presence of a storage backend (filesystem and below) doing de-duplication.
The test will run for 1 minute with 16 processes in parallel doing the same thing and the reporting is done for the whole group of processes.
cd /var/virtualization fio --ioengine=libaio \ --filename=fio.test \ --size=256M \ --direct=1 \ --rw=randrw \ --refill_buffers \ --norandommap \ --bs=8k \ --rwmixread=70 \ --iodepth=16 \ --numjobs=16 \ --runtime=60 \ --group_reporting \ --name=fio-test
gfapi
cd /var/virtualization fio --ioengine=gfapi \ --volume=virtualization \ --brick=10.1.120.11 \ --filename=fio.test \ --size=256M \ --direct=1 \ --rw=randrw \ --refill_buffers \ --norandommap \ --bs=8k \ --rwmixread=70 \ --iodepth=16 \ --numjobs=16 \ --runtime=60 \ --group_reporting \ --name=fio-test