Just when you thought EMC was done with alphabet soup acronyms and on to starting everything with a V or X along comes the DSSD D5. DSSD is a company acquired by EMC back in 2014 and their “D5” is an all flash storage array geared toward super IO intensive workloads. It’s new system that’s been in development for awhile so you may not see a lot of features you would find on other all flash arrays. Instead it’s been built from the ground up as a “go fast machine” that connects to Linux hosts via PCIe Gen 3.

Recently I was able to attend an EMC/DSSD presentation on the D5. Here are my notes from that event. Any numbers, details, etc. may change from the time of this post (or I may have mistaken something), so please consult with your EMC rep or valued partner for more details. EMC and partners can find more details on EMC’s site, https://www.emc.com/auth/rpage/ec-for-dssd.htm

DSSD D5

5U rack scale flash platform

Physically very deep, and very heavy (140lbs)

36 flash modules Flash module with ASIC and proprietary software Can be purchased with half pop (18 count) 2TB/4TB FMs (larger ones on the way)

Redundant controllers (Called an IOM or service module) No serial, connect via SUB Each IOM has an Ethernet port for mgmt

Redundant power supplies (x4)

Redundant fans (x5)

48 PCIe Gen3 x4 Client Ports per IOM (controller) Total of 96 PCIe Gen 3 ports

Redundant Control Modules (CM) Full of DRAM

Uses NVMe storage protocol

Max Performance on *single* DSSD D5 unit

4k Random Reads, 8M to 10.6M IOPS

32k Random Reads, 101.4 GB/s

32k Sequential Writes, 21.6 GB/s

DSSD Flash Module (FM)

18 or 36 FMs per D5

2TB or 4TB

Built in DRAM????

Future FMs will offer grater capacities and support 3D NAND and NGNVM

Industry’s first hot-swappable and dual connected PCIe Gen3 x4 based FM

Power delivery to flash bursts up to 60 Watts

Hot swappable

DSSD PCIe Card

Cable lengths, 1m, 2m, 3m or 4m copper Plans for optical cables

Supports up to two cards per host Can support more, but right now is limited without qualification

Always on multipathing

“Flood”

Flood is the client software, CLI, BUI

Same name for all the software that runs on the D5, client cards, etc

Direct memory API Allows data access with less system integration layers to improve formance Maps users space directly to flash

Object store supporting key-value, directory, block and file object types

Data protector, Data manager, Application manager, appliance CLI

DSSD uses object store Presented as volumes as block stores to the clients Can use API to directly access objects

Volumes can contain all object types and support FLENs Fragment length is configured per object, from 64B to 32KB

Object types: Volume Presented from the D5 to the client, clients create objects in Directory Key-Value Block Objects are containers of fragments IO must be FLEN aligned Higher performance than file objects Uses API or block driver (API is faster) File Allow non-aligned IO POSTIX Compliance DSSD application specific plug-ins available



Data Resiliency