WASim

FTL Simulator only for WA (Write Amplification)

Requirement

• Python 3.x
• matplotlib
• tqdm

Usage

[Simulate with one configuration]

python wafsim.py -c $(config file)

[Parse MSRC trace into WASim trace]

1. Download MSRC trace in SNIA site

2. Extract csv files in MSRC directory.

3. Execute msrc_parser.py. *.trace files will be created in same directory.

   python util/msrc_parser.py -i MSRC
   

[Visualize MSRC trace result]

python util/result_viz.py --dir $(result directory)

[Visualize MSRC trace distribution]

python util/trace_dist_viz.py --input $(.trace file or directory)

Configurable Parameter

[Simulation Parameters]

Parameter	Type	Description
simulation_type	str (Synthetic, Trace)	Determine simulation type
simulation_tag	str	Simulation identifier. Need for debug file name
debug_victim_hist	bool	Determine whether to log histogram of victim block's utilization distribution
debug_final_u	bool	Determine whether to log final utilization distribution
debug_gc_stat	bool	Determine whether to log GC statistics
seed	None, int	Set seed for random generator
warmup_type	None, 0, 1, 2	Determine warm-up type
fill_percentage	int	Fill percentage during warm-up
invalid_percentage	int	Invalid percentage during warm-up

[Synthetic Workload Parameters]

These parameters are only valid when simulation_type is Synthetic.

Parameter	Type	Description
simulation_time	int	Set simulation time
iteration_num	int	Set the number of simulation with same configuration
working_set_percentage	int	Percentage of LBA used
workload_type	0, 1, 2, 3	Determine workload type (e.g., seq write, hotcold)
read_ratio	float	Read request ratio
locality	float	Hot data ratio

[Trace Workload Parameters]

These parameters are only valid when simulation_type is Trace.

Parameter	Type	Description
trace_path	str (file, dir)	Path includes .trace file
dynamic_capacity	bool	If true, block number is adjusted to the largest address in trace file
execute_percentage	int	Percentage of request in trace to run

[SSD Parameters]

Parameter	Type	Description
block_num	int	-
page_per_block	int	-
page_size	int	-
victim_selection_policy	Greedy, CB, CAT, LCCB	-
utilization_factor	int	Only valid when victim selection policy is LCCB
hotness_factor	int	Only valid when victim selection policy is LCCB
decay_factor	int	Only valid when victim selection policy is LCCB
gc_start_threshold	float
gc_mode	0, 1	Determines whether GC reclaim a specific number or until a specific threshold
gc_reclaim_block	int	Only valid when gc_mode is 0
gc_reclaim_threshold	float	Only valid when gc_mode is 1

MSRC Example

1. Simulate GC with three policies (Change victim_selection_policy parameter)

   python wafsim.py -c config/msrc.cfg
   

2. Visualize result. res.png and res.eps will be created in workspace.

   python util/result_viz.py --dir res