Dual-Mode SSD Architecture for Next-Generation Hyperscale Data Centers Untitled document

18 Pages·2017·0.63 MB·English

Dual-Mode SSD Architecture for Next-
Generation Hyperscale Data Centers
Feng Zhu
Alibaba Group
2018 Storage Developer Conference. © Alibaba Group. All Rights Reserved. 1
Challenges of hyperscale data centers
 Diversified, fast-changing workloads
Performance
 Continuous pressure for TCO and
supply improvement
 Demand for “white box” of I/O path -
Service Flexibility
more control and determinism
 Quick response to issues and feature
requests
 Demand for hardware/software co-
White
TCO optimization
Box
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AliFlash_Alibaba’s self-developed SSDs
AliFlash V1 AliFlash V2 AliFlash V3
• High performance • NVMe U.2 SSD • Dual-mode SSD with
PCIe SSD open channel
• Customization for
• Host based FTL. applications • Deep optimization
Control on SW/HW for applications
• Cost down by 20%
• >20k devices serving • Being productized
in Alibaba data centers
2016 2017 2018
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First Productionized Open Channel SSD
 Alibaba’s self-developed Open Channel SSD
- AliFlash V3
 Deployment ongoing in Alibaba data centers
 Major milestone since the announcement of
Alibaba’s Open Channel SSD Architecture in
FAST’2018
 Collaborating with multiple SSD vendors to
build an ecosystem
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Why open channel
 New SSD architecture for next-generation
data centers
Application 1 Application 2 Application 3
 Enable hardware/software co-optimization
 Maximum flexibility for different workloads
Fusion Engine Software
 Generic block device
Alibaba Open Channel SSD Platform
 Customized FTL
Open Channel Mode Device Mode
 Deep integration with applications
Alibaba Open Channel SSD Specification
 Reduce time & complexity of SSD
qualification
Alibaba Open Channel SSD (AOC SSD)
 New media ready: QLC NAND, 3D X-
point, SCM, ...
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Alibaba Open Channel Architecture
 Open Channel mode
 Direct access to the physical
media, and max utilization of the
media capability
 Fully control of the data
placement and I/O scheduling
 FTL/GC customization based on
application I/O pattern -> reduced
WA
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Customization for Alibaba data centers
Requirement
analysis
In-house
Applications developed
storage solutions
SW/HW
SW/HW co-
co-design
optimization
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© 2017 Alibaba Group
Alibaba Open Channel SSD Software
 Host-side software stack developed by Alibaba
 Kernel-space AOC SSD Driver + Block Device FTL
 User-space AOC SSD Driver integrated with Alibaba’s
Fusion Engine software
 User-space customized FTL solutions
 Management, monitoring and test tools
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Kernel-space AOC SSD Solution
Application  Work like generic block device
 Covers most of the legacy use
Fusion Engine
User Space File System
cases
 Equivalent performance and
AIO
functionality as standard NVMe SSD
 Customized improvements and
AOC SSD Kernel-Space Driver & FTL
extensions (e.g. scheduling & QoS)
Alibaba Open Channel SSD
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User-space AOC SSD Solution
 Entire I/O path in user space - low
Application
software overhead
Fusion Engine User Space User Space
 Deep integration with application - full
File System KV Engine
benefits from hardware/software co-
AOC SSD User Space FTL
optimization
Solutions
 Optimize data placement, coordinated
AOC SSD User Space Driver
background tasks (garbage collection)
 Customized FTL solutions (e.g. Object
Alibaba Open Channel SSD
SSD)
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