Write-intensive and mixed-use applications, particularly those with high random write workloads, demand exceptional performance from underlying storage, such as SSDs. With these performance demands, there are factors that can significantly impact SSD write performance and its life expectancy such as drive writes per day1 (DWPD) endurance and overprovisioning (OP). By using NVMe™ namespaces, you can divide an SSD into logically separate and individually addressable storage spaces so that OP can be effectively managed and storage performance can be improved.
It’s also important to understand that read-intensive SSDs with 1 DWPD endurance ratings often have limited OP, causing random write performance constraints. In the past, there was availability of off-the-shelf SSDs that featured much higher endurance ratings and higher random write performance that could help to mitigate these performance concerns. However, gone are 25 DWPD and 10 DWPD SSD models, while some suppliers have even removed or limited 3 DWPD mixed-use models from their portfolios.
Fortunately, NVMe namespaces fill a gap lost from higher endurance rated SSDs and offer a solution that increases performance and emulates higher DWPD endurance ratings.
Increases Performance
A namespace within the NVMe specification divides an SSD into logically separate and individually addressable storage spaces with their own input/output (I/O) queue. Adjusting NVMe namespace sizes can increase the performance of locally attached SSDs while emulating higher DWPD endurance. When you create an NVMe namespace, the remaining SSD capacity can be allocated to the OP pool. The increased OP enhances random write performance by providing more space for background wear leveling and garbage collection operations, which in turn, lead to faster write speeds and an overall improvement in operational efficiency.
We tested the NVMe namespace capability in our Innovation Lab using a 1 DWPD KIOXIA CM7-R Series SSD, and we reduced the namespace size from 7.68 terabytes2 (TB) to 6.4 TB. The results from the test showed a significant improvement for both 100% random write performance and random 70% read/30% write performance, as depicted below:
Emulates Higher Endurance DWPD SSDs
NVMe namespaces can also be used to emulate higher endurance DWPD SSDs. For example, a 1 DWPD KIOXIA CM7-R Series SSD can be configured to emulate a 3 DWPD SSD by reducing the namespace size. This configuration change can effectively increase the perceived DWPD endurance of the drive, allowing it to handle more demanding write workloads while maintaining acceptable performance.
A Flexible Option that Can Change with Use Case
Of course, the downside of a reduced namespace size is that the useable capacity is also reduced. However, customers have claimed that there is a lot of unused capacity sitting idle in data centers which could be used for namespaces. If the use case changes, such that more capacity is needed, you can delete the namespace and recreate it to accommodate more capacity usage rather than an increased performance or endurance use case, provided the old data is invalid or copied elsewhere since deleting a namespace also deletes its data content.
Benefits of NVMe Namespaces
NVMe namespaces provide a powerful mechanism for enhancing the performance of SSDs, particularly for applications requiring high random write and mixed-use workloads. By strategically adjusting namespace sizes, users can optimize OP, improve performance, and effectively emulate higher endurance DWPD SSDs, maximizing the value, flexibility and longevity of their storage infrastructure.
Check out the complete NVMe namespace test in the performance brief available here. Also see a video on NVMe namespaces from KIOXIA’s own Tyler Nelson here.
NOTES:
1 Drive write(s) per day (DWPD). One full drive write per day means the drive can be written and re-written to full capacity once a day, every day, for the specified lifetime. Actual results may vary due to system configuration, usage, and other factors. Read and write speed may vary depending on the host device, read and write conditions, and file size.
2 Definition of capacity - KIOXIA Corporation defines a megabyte (MB) as 1,000,000 bytes, a gigabyte (GB) as 1,000,000,000 bytes and a terabyte (TB) as 1,000,000,000,000 bytes. A computer operating system, however, reports storage capacity using powers of 2 for the definition of 1Gb = 230 bits = 1,073,741,824 bits, 1GB = 230 bytes = 1,073,741,824 bytes and 1TB = 240 bytes = 1,099,511,627,776 bytes and therefore shows less storage capacity. Available storage capacity (including examples of various media files) will vary based on file size, formatting, settings, software and operating system, and/or pre-installed software applications, or media content. Actual formatted capacity may vary.
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KIOXIA America, Inc. may make changes to specifications and product descriptions at any time. The information presented in this blog is for informational purposes only and may contain technical inaccuracies, omissions and typographical errors. Any performance tests and ratings are measured using systems that reflect the approximate performance of KIOXIA America, Inc. products as measured by those tests. In no event will KIOXIA America, Inc. be liable to any person for any direct, indirect, special or other consequential damages arising from the use of any information contained herein, even if KIOXIA America, Inc. are advised of the possibility of such damages.
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