Eliminating the I/O blender: The promise of flexible data placement

John Mazzie, Sayali Shirode | July 2023

Flexible data placement (FDP) is a possible forthcoming feature of the NVMeTM specification that has been proposed by Google and Meta.1 The purpose of this feature is to reduce the write amplification (WA) when multiple applications are writing, modifying and reading data on the same device.2 Benefits of reduced WA for these companies come in the form of more usable capacity and potentially a longer useful life for each device.

We proposed an experiment to determine how helpful FDP might be. In this test, we are using a 7.68TB Micron 7450 PRO SSD split into four equal (1.92TB) namespaces and executing parallel flexible input/output tester (fio) workloads on each namespace.3 These workloads are all sequential writes but vary in block size (4K, 16K, 64K and 256K). We also execute these workloads individually to four 1.92TB Micron 7450 PRO SSDs, which we imagine as the most optimal implementation of FDP where all application data receives dedicated NAND space and does not get interleaved on the device as shown in Figure 1.

data layout of FDP implementation

Figure 1

data layout of FDP implementation

Figure 2

write amplification chart

Though this is a simple experiment, it shows the potential benefits for FDP implementation on future devices. We can also see how some applications, which are designed to write sequentially as much as possible, would benefit from FDP when contending for the same drive resources.

1. For additional information on FDP, see 
2. For additional information on write amplification, see 
3. Fio documentation is available here: 

© 2023 Micron Technology, Inc. All rights reserved. All information herein is provided on an "AS IS" basis without warranties of any kind. Products are warranted only to meet Micron’s production data sheet specifications. Products, programs, and specifications are subject to change without notice. Micron Technology, Inc. is not responsible for omissions or errors in typography or photography. Micron, the Micron logo, and all other Micron trademarks are the property of Micron Technology, Inc. All other trademarks are the property of their respective owners. Rev. A 01/2023 CCM004-676576390-11635

Principal Storage Solutions Engineer

John Mazzie

John is a Member of the Technical Staff in the Data Center Workload Engineering group in Austin, TX. He graduated in 2008 from West Virginia University with his MSEE with an emphasis in wireless communications. John has worked for Dell on their storage MD3 Series of storage arrays on both the development and sustaining side. John joined Micron in 2016 where he has worked on Cassandra, MongoDB, and Ceph, and other advanced storage workloads.

Storage Solutions Engineer

Sayali Shirode

Sayali received an M.S. in electrical and computer engineering from Colorado State University in 2015. She's currently a Storage Performance Engineer at Micron's Austin location and has previously worked as Firmware Test Engineer at Micron's Colorado location. She focuses on analyzing the performance of data center applications.