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CMU-SAFARI / MQSim

MQSim is a fast and accurate simulator modeling the performance of modern multi-queue (MQ) SSDs as well as traditional SATA based SSDs. MQSim faithfully models new high-bandwidth protocol implementations, steady-state SSD conditions, and the full end-to-end latency of requests in modern SSDs. It is described in detail in the FAST 2018 paper by Arash Tavakkol et al., "MQSim: A Framework for Enabling Realistic Studies of Modern Multi-Queue SSD Devices" (https://people.inf.ethz.ch/omutlu/pub/MQSim-SSD-simulation-framework_fast18.pdf)
https://people.inf.ethz.ch/omutlu/pub/MQSim-SSD-simulation-framework_fast18.pdf
MIT License
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OP ratio #49

Open ZiyangJiao opened 3 years ago

ZiyangJiao commented 3 years ago

Just to confirm, I'm wondering does it mean (T - U) / T or (T-U) / U in MQSim? Thank you for your time and help!

tavakara commented 3 years ago

Hi @ZiyangJiao, Can you please clarify which parameter are you referring to?

ZiyangJiao commented 3 years ago

Thank you for your reply. It's Overprovisioning_Ratio: the ratio of reserved storage space with respect to the available flash storage capacity. Range = {all positive double precision values}.

ZiyangJiao commented 3 years ago

Plus, I'd like use MQSim to validate the write amplification caused by garbage collection. But it seems that MQSim doesn't support 100% preconditioning(setting initial occupancy = 100% and working set = 100%) .

tavakara commented 3 years ago

Hi @ZiyangJiao, As you can find the usage of the parameter in classes like Logical_Address_Partitioning_Unit.cpp, it is (T-U)/T. In other words, it is the ratio of the reserved space to the total available storage space.