hardware

EMC VNX: Different types of Disk Shelves

In this short article I would like to describe different types of DAE (Disk Array Enclosure) that you can meet within the EMC VNX installation. As I described in the previous article disks cna be found in DPE (Disk Processor Enclosure) which is the enclosure that host both Storage Processor and shelf of 25 (2,5″) disks. Of course you can add more disks, with Disk Processor Enclosure.

Types of DAEs available with EMC VNX:

2U in size – 25 drive DAE paired with 2,5″ SAS drives

This enclosure host 25 drives that can be either SAS or SSD disks. Take a look at the front of the 25-drive DAE hosuing 2,5″ SAS drives:

25-drive DAE  Front view

25-drive DAE Front view

Nothing fancy here, easy access to all the drives with status LEDs that help you indicate the issue with any of the harddisk. Not let’s take a look at the backend:

25-drive DAE - Back view

25-drive DAE – Back view

As you can notice there are two Power Supplies that gives you the opportunity to connect the disk shelf to 2 different power sources. And a close-up to the back of the 25-drive DAE:

25-drive DAE - Close-up

25-drive DAE – Close-up

 

3u in size – 15-drive DAE

The 15-drive DAE support 2,5″ SAS, 3,5″ NL-SAS, and 3,5″ flash srives. It may be populated with any combination of those 3. These options enables you to configure your system for optimal efficiency and performance. As you well know:

  • flash drives = extreme performence,
  • mid-tier SAS drives = good balance of price and perfomence,
  • cost-effective NL-SAS drives = capacity up to 2TB per disk.
15-drive DAE - Front view

15-drive DAE – Front view

Again – nothing fancy in the front view. Easy access to all drives, that can be replaced at any time + Status LEDs indicating any issues with disks.

15-drive DAE - Back view

15-drive DAE – Back view

As you can notice there are two Power Supplies that gives you the opportunity to connect the disk shelf to 2 different power sources. Take a look at the closeup of backend:

15-drive DAE - closeup

15-drive DAE – closeup

4u in size – 60-drive DAE

The 60 – drive DAE can be populated with 2.5” SAS drives using a 3.5″ – carrier . The 60 – drive will hold up to 60 rotating or SSD – type drives in 3.5” (EFD, 7200 rpm and 10 K rpm) and 2.5” (EFD, 7200 rpm, 10 K rpm) form factors. For the 3.5” drive types , 15 K rpm drives are not supported in this enclosure.

You can access the disk from the top:

60-drive DAE - Top view

60-drive DAE – Top view

The 60 enclosure may be the first DAE and contain the vault drives ( row A, positions 0 – 3) for the VNX5700 and VNX7500 models. If there is a partially filled row in the DAE, the remaining empty slots will be populated with fillers.

 

EMC VNX hardware overview

The VNX series is the family of midrange-to-enterprise products. It unifies file-based and block-based offering into a single product.

In this post I would like to describe hardware components a little bit more.

Lets take VNX5500 as an example:

Figure 1. Block and File (Unified) VNX5500 platform

Figure 1. Block and File (Unified) VNX5500 platform

Disk-processor enclosure (DPE)

The enclosure is 3U in size and houses each storage processor and the first tray of disk. It can be found on the figure above with 25 (2.5 inch) disks. Let’s take a look at rear view:

Figure 3. Back view of DEP with SP A (right) and SPB (left)

Figure 2. Back view of DEP with SP A (right) and SPB (left)

Storage processors (SPs)

SP support block data with UltraFles I/O technology – supporting Fibre Channel, iSCSI and FCoE protocols. Storage Processors provide access for all external hosts and the file side of the VNX array.

Figure 4.  Closeup of DPE-based storage processor

Figure 3. Closeup of DPE-based storage processor

On above example SPs are located in Disk Processor Enclosure (DPE).

Storage processor enclosure (SPE)

The enclosure is 2U in size and houses each storage processor. It can be found in VNX5700 and VNX7500 models, support maximum of 500 (VNX5700) and 1,000 drives (VNX7500)

 Control Station

Control Station are 1U in size and provide management functions to the file-side components (referred to as Blades or Data Movers). The CS is responsible for Blade failover. To provide HA Control Station might be configured with a matching secondary CS.

Figure 4. Control Station rear view

Figure 4. Control Station rear view

Data Mover

Data Mover (or Blade) access data from the back-end and provide host access using the same UltraFlex I/o technology that supports NFS, CIFS, pNFS protocols. The Data Movers in each array are scalable and provide redundancy.

Data Mover Enclosure (DME)

The DME is 2U in size and houses the Data Movers (Blades).  The DME is similar in front to SPE and is used on all VNX models that support file.

Figure 5. DME rear view

Figure 5. DME rear view