On Tue, 21 Mar 2017 at 13:21, Stefan Hajnoczi <stefa...@gmail.com> wrote:
> On Sat, Mar 11, 2017 at 11:54 AM, Ashijeet Acharya > <ashijeetacha...@gmail.com> wrote: > > This series optimizes the I/O performance of VMDK driver. > > > > Patch 1 makes the VMDK driver to allocate multiple clusters at once. > Earlier > > it used to allocate cluster by cluster which slowed down its performance > to a > > great extent. > > > > Patch 2 changes the metadata update code to update the L2 tables for > multiple > > clusters at once. > > This patch series is a performance optimization. Benchmark results > are required to justify optimizations. Please include performance > results in the next revision. > > A popular disk I/O benchmarking is fio (https://github.com/axboe/fio). > I suggest a write-heavy workload with a large block size: > > $ cat fio.job > [global] > direct=1 > filename=/dev/vdb > ioengine=libaio > runtime=30 > ramp_time=5 > > [job1] > iodepth=4 > rw=randwrite > bs=256k > $ for i in 1 2 3 4 5; do fio --output=fio-$i.txt fio.job; done # > WARNING: overwrites /dev/vdb > > It's good practice to run the benchmark several times because there is > usually some variation between runs. This allows you to check that > the variance is within a reasonable range (5-10% on a normal machine > that hasn't been specially prepared for benchmarking). I ran a few write tests of 128M using qemu-io and the results showed the time to drop to almost half, will those work? Although, I will also try to use the tool you mentioned later today when I am free and include those results as well. Ashijeet > > > Stefan >