libfio_fileserver

This is a loadable engine for fio to test something similar to the file server access pattern where a number of files is sharded over several levels of subdirectories.

Building

• Clone this repository
• Clone or symlink the source code directory for your exact fio version in ./fio subdirectory
• Install g++
• Run make

Compatibility

fio 3.15 or later.

Usage

fio -name=test -ioengine=./libfio_fileserver.so -directory=/home/bench \
    -chunk_size=256k -size=10G -direct=1 [-dir_levels=2] [-subdirs_per_dir=64] \
    -bs=256k -rw=randwrite [-fsync_on_close=1] [-sync=1] [-numjobs=16 -group_reporting]

Notes:

• direct=1 is optional, but without it you’ll be benchmarking the page cache
• bs=256k must be less or equal to chunk_size
• fsync=N is supported, but it only fsyncs a random file
• reads return error when encountering a non-existing file
• You can also use various distribution parameters (zipf, etc)
• I/O is done using synchronous syscalls, thus iodepth is not supported

Because of the synchronous syscalls it’s slightly tricky to use parallelism correctly. So, for example, to fill a directory with 262144 4k files, run:

fio -thread -name=test -direct=1 -ioengine=./libfio_fileserver.so -fsync_on_close=1 \
    -directory=/home/bench -chunk_size=4k -size=1G -bs=4k -rw=write:508k \
    -numjobs=128 -offset_increment=4k -group_reporting

License & Author

• Author: Vitaliy Filippov vitalif[at]yourcmc.ru, 2020
• License: GNU GPL v2.0 or later version