An Introduction to Unity, EMC’s New Storage Array


EMC is rolling out a new SAN array lineup called the EMC Unity. At a high level the Unity comes into two main flavors, all flash and hybrid, and support fibre channel, iSCSI, NFS, and CIFS/SMB. It’s a mid-tier array, destined to supplant higher level VNXe arrays, and lower level VNX2 arrays. Specifically, the VNXe 3200 and VNX 5200, 5400, 5600, & 5800. As for right now I’m not aware of any plans to depreciate those arrays so if you’ve just picked one up or aren’t ready to jump into some cutting edge EMC tech then no need to worry.

If you do get the an EMC Unity you’ll get a brand new HMTL5 GUI (no more Java, rejoice!) array with hardware is reportedly 2.5x as powerful in half the physical footprint.

In addition to the physical hardware platforms, there’s also a virtual Unity (UnityVSA) without various size and scale options.

Note that this information comes from Pre-EMC World 2016 sources and may have received updates at EMC World. Also, it’s EMC, so various options and features may not yet be GA.


General Features

  • All Unity arrays support SAN and NAS protocols
    • Fibre Channel
    • iSCSI
    • NFS v3 & v4
    • Secure NFS
    • CIFS/SMB
    • FTP/SFTP
    • Also supports VMware Virtual Volumes (VVOL)
  • A single storage pool can service LUNs, file systems, and VVols
    • FAST VP to rebalance across drive tiers
    • I don’t believe the storage pools can be shrunk
  • NAS services via configurable “NAS Servers”
    • Multi-tenancy, each NAS Server exists as a separate file server with it’s own configuration
  • File system able to auto-shrink & extend for thin file systems
    • Dynamically allocates free space for the file system to maintain a 70-75% used-to-allocated ratio
  • Supports various SMB protocol options & features
    • Continuous availability
    • Protocol encryption
    • Access Based Enumeration
    • Distributed File System
    • Branch Cache
    • Offline Availability
    • Umask
    • Dynamic access control
    • Hyper-V shared VHDX
    • Antivirus


Two Physical Lines, All Flash & Hybrid

  • Unified redundant hardware
    • Unified equipment for SAN & NAS, no need for extra equipment (eg. Data Movers & Control Stations)
      • Storage pools can service both SAN and NAS data
    • 2x Service Processors
      • Internal SSD on each for write cache
      • 1st four drives in array for OS & vault
  • Updated Hardware
    • Dual storage processors
      • Intel E5-2600 processors, 6-12 cores each
      • Active-active data processing
      • BBUs built into DPE (may also be referred to as a Storage Processor Enclosure)
        • BBUs are field replaceable but require the SP to be down (physically removed) for replacement
    • Connectivity options:
      • 2x 1Gb Ethernet for mgmt and service
      • 2x 10Gb Ethernet Base-T (RJ45) for font-end connectivity
      • 2x CNA ports for front-end connectivity, configured during install for FC or Ethernet
      • Additional IO module support (1 per SP):
        • 4 port 12Gb SAS
        • 4 port 4/8/16 Gb Fibre Channel
        • 4 port 1Gb Ethernet
        • 4 port 10Gb Ethernet Base-T
        • 2 port 10Gb Ethernet
        • 4 port 10Gb Ethernet
    • Cannot use VNX drives or DAEs
    • 12Gb SAS backend (vs. 6Gb on VNX)
  • Scaling model versions
    • 300/400/500/600 in hybrid or all flash configurations
      • All flash configuration does not support FAST Cache
    • Unity 300:
      • Hybrid: 150 drives, 900 TB raw (or 1.5 PB raw per second doc I have)
        • 800 GB max FAST Cache
      • Flash Only (Unity 300F): 150 drives, 480TB raw
      • 48GB memory
    • Unity 400:
      • Hybrid: 250 drives, 1.2 PB raw (or 2.5 PB raw per second doc I have)
        • 1.2 TB max FAST Cache
      • Flash Only (Unity 400F):250 drives, 800 PB raw
      • 96GB memory
    • Unity 500:
      • Hybrid: 350 drives, 2.1 PB raw (or 3.5 PB raw per second doc I have)
        • 500 drive capacity planned within a year
        • 3.2 TB max FAST Cache
      • Flash Only (Unity 500F):350 drives, 1.12 PB raw
      • 128 GB memory
    • Unity 600:
      • Hybrid: 500 drives, 3.0 PB raw (or 5.0 PB raw per, get this, a second doc I have)
        • 1000 drive capacity planned within a year
        • 6 TB max FAST Cache
      • Flash Only (Unity 600F):500 drives, 1.6 PB raw
      • 256 GB memory
  • 4k drive block size on physical drives, 520 byte block size on Flash drives
    • 4k block size is specially 4160 bytes, 4096 bytes for the block + 64 bytes for error checking
  • Carries over VNX2 drive mobility


UnityFlashThe all flash Unity features a solid, silver double helix.



While the helix on the hybrid Unity is blue and silver.


Unity as a Virtual Storage Appliance (UnityVSA)

  • There are two versions available, free (Community Edition) and licensed (Professional Edition)
    • Community Edition is 4TB
      • 12 GB memory
      • Can be upgraded to Professional Edition
    • Professional Edition is licensed by capacity on a yearly basis
      • 10TB, 25TB, and 50TB
      • 16 or 18 GB memory for ESXi 5.5 or 6.0 respecfully
      • Smaller versions can be upgraded to larger ones
  • Serves through iSCSI, NFS, or CIFS via 1 or 10 GbE
  • As far as I’m aware, both versions offer the same functionality
  • Supports asynchronous replication to a VNXe3200/1600, vVNX, or another unity system
  • Data at Rest Encryption supported



Unity’s Software & Configuration Features


  • HTML 5 GUI
    • Get the fuck out of here, Java
  • Built in performance data collection
    • IOPS, Bandwidth, IO sizes available for file data
    • No known (to this author at least) ability to export performance data
  • Available QoS feature
    • System wide pause/resume control (not sure why this would be needed)
    • Ability to create host IP based policies
    • Only applicable to LUNs, attached snapshots, and VMFS datastores
  • File systems scale to 64TB and support system shrinking, VMDK cloning, and pointer-based snapshots
  • Pool creation
    • Drives are added automatically to a pool per user’s requirements, users cannot add specific drives to a pool
      • Apparently drive mobility will let you manually rearchitecture drive locations after the fact
  • Hot spare policy still 1 per 30, cannot be adjusted
  • New REST API
  • CLI available (UEMCLI)
  • Unisphere Central can be used to monitor Unity as well as VNX systems
  • Still has FAST Cache and FAST VP functionality
    • FAST Cache can be shrunk and expanded online
    • No FAST Cache functionality on all flash Unity models
    • Similar structure to VNX2
      • Same configurable tiering options & schedules
      • 64KB block size for FAST Cache
      • 256 MB block size for FAST VP
  • Data-At-Rest Encyrption (D@RE) is available
    • Unique encryption key per drive
    • Must be configured at time of installation, cannot be disabled afterward
    • EMC estimates a 0% to 5% impact on performance when enabled
    • Currently only leverages internal keys


Data Replication, Migration & SnapShots

  • Unity uses redirect on write snapshots
    • Works on both file and block data
    • 256 snapshots per source
    • 3008 to 36020 snapshots per array (depending on model)
  • Built in replication functionality
    • Asynchronous replication for file and back
      • Snapshot based
      • One to many (or many to one) supported
    • Synchronous replication for block data only
      • One to one replication supported
      • Looks like this is only supported via Fibre Channel
    • No incremental attach
    • No bandwidth throttling
  • SAN Copy is supported with a Unity system as a target from a VNX or VNX2 array
  • Supports NDMP 3-way backups
    • 2/8/8/20 concurrent streams (scaling per Unity version I believe)



  • Software-as-a-service cloud management dashboard
  • Dashboard widgets including general health, alerts, and pool predictive capacity
  • Aggregated listings such as alerts, systems, pools
  • Early access available, GA slated for late 2016


Unity Road-map (that which EMC is planning on adding to the product line)

  • Data in Place upgrades
  • Increased capacity on Unity 500 & Unity 600 systems (see above)
  • FIPS 140-2 Level 1 validation
  • ViPR Essentials (estimated July 2016)
  • External key management (for Data-At-Rest Encryption)
  • Integration with ProtectPoint


Additional Information