EMC Unified Storage VNXe 3100

EMC, which is well known for its enterprise class storage solutions, has recently entered the small and mid-sized enterprise market with the introduction of two new unified storage products meant specifically to cater to their needs. These are the VNXe 3100 and 3300 series of unified storage solutions, of which we received the former for review, and discovered several interesting features that make it very relevant for smaller enterprises.

The key thing to understand about this product range is that it's meant to consolidate all the back-end storage in your organization into a single box. So if it's file based storage, the VNXe box will act as a NAS, and if it's transaction oriented applications like databases that require block level access, then it will act as a SAN. The box has all the technologies required to handle both kinds of jobs. It supports both CIFS and NFS protocols for file level access by Windows and Linux based clients, and the iSCSI protocol for block level access.

Extremely Easy to Manage

If you've ever managed a SAN, you'll remember what a pain it can be, unless you're a storage specialist with a few certifications in your pocket. With the VNXe, you don't have to be a storage specialist. It has a management software called Unisphere, which has built-in wizards to do everything, right from volume management to RAID configuration, and even application oriented tasks like creating Exchange mailboxes. Plus, the box comes with advanced features like snapshot for file recovery, backup applications, quota setting for users, data security, and thin provisioning. This makes sense because smaller enterprises typically have lesser manpower to manage the entire IT infrastructure. They don't have dedicated storage specialists for instance to handle the SAN, and another one for the NAS, and so on. EMC aptly terms the SME IT manpower as 'IT generalists', who'll handle just about everything.

It also has built in support for creating virtualization data stores for both VMware and Hyper-V. We managed to easily create and configure virtual machines for VMware, connect a VMware ESX Server host to it, and configure storage for the virtual machines, using its built-in wizards. The process was similar to the process for configuring the iSCSI storage. Similarly, you can configure the storage for Hyper-V. Another advantage of using VNXe is that it lets you create storage for Microsoft Exchange. Here you can configure the number of mailboxes and the size allotted to each. Also you can enable thin provisioning which gives flexibility in storage.

VNXe also lets you create a performance and a hot spare pool. You can configure storage disks for pooling. Again it is quite easy with the Unisphere UI. You can also view the health status of the system. It gives you a detailed and interactive display of the hardware and also shows you where the problem lies. We checked this by unplugging the power supply in one of the disk processor enclosures. When we checked the system health in Unisphere, we got the prompt with the proper view of the problem.

The Technical Side of VNXe 3100

The box we received for review is available in single and dual storage processor versions. It supports 12 hard drives per enclosure, so the single processor version supports up to 48 drives, while the dual processor version can go up to 96 drives. Additional drives are added by daisy chaining more DAEs (Disk Add-on Enclosures). With this, the maximum raw capacity supported by the box can go up to a whopping 192 TB. The VNXe 3100 supports SAS and NL-SAS drives.

Our Experience With the Setup

After we finished putting the boxes in place and powering them on, we downloaded and ran the VNXE Connection Utility software. This helps discover and connect storage with the system. We chose the Auto Discovery option, which automatically detected the storage. Next, we assigned an IP address to configure network access for this device.

After that, we started playing around with the device to see how easy was it to setup. We first opened Unisphere, its GUI based management software that lets you control all operations on the device. Using that, we created a volume as a generic iSCSI host and mounted it on a Windows 2008 R2-based machine using Microsoft's iSCSI initiator. We could do this in exactly seven simple steps. We then created 100 GB of storage on this device using its web-based wizard. It gave us three options to configure protection for the storage, which basically deals with doing replication and taking snapshots. The first option would not configure protection storage immediately while the second option automates the snapshot protection schedule that can be configured later. The third option lets you configure and schedule protection storage, but you need to purchase a separate license for that. We chose the second option. In the next step we reserved space for protection storage. The minimum protection size is 105% of the primary storage. With this the total storage size went upto 205 GB which includes protection and primary storage. Next we configured host access so that it can be accessed through a host machine. Here we entered the IQN, which is actually the iSCSI address associated with the host machine. We got this address from the iSCSI initiator. We also configured the access type. Here we chose the virtual disk and snapshot option. In the next step we confirmed all these details, and within a minute the raw partition was created. However, this is not accessible until you format it, which can be done from the disk management console (by running the 'diskmgmt.msc' command from Windows) and then assigning the formatted drive a letter.

I/O Performance

Considering that it's a pretty complex box with lots of features, we managed to test only its I/O performance in SAN mode this time. For this, we used the IOMeter benchmark, which is a global standard for testing the I/O and throughput performance for any kind of storage device. Next time, we'll get into other exciting areas like measuring its performance while doing virtualization, setting up MS Exchange mailboxes, throughput in NAS mode, etc.

We used the same 100 GB iSCSI target and host that we had created in the setup. Our host was a 24-core Intel Dunnington based server, so we configured IOMeter to throw requests at the VNXe from 24 different workers. Not only that, but we sent the requests with four different payloads-32, 64, 128, and 256 kB. The requests themselves were of four different kinds-100% random read/write, and 100% sequential read/write. The test results can be seen in the table.

The performance of the VNXe is pretty impressive we must say. The number of I/O operations per second dropped as we increased the payload from 32 to 256 kB, which is only logical and is bound to happen. However, the thing to check is whether it drops to a level where the throughput gets impacted. That didn't happen. The throughput remained rock steady for all payloads. You'll notice from the test results table that the throughput remains at 112 MB/s in sequential reads. In case of sequential write, the throughput actually went up slightly with higher payload. In random read/write, the throughput remains steady.

Bottomline: Given the performance we got over iSCSI, and the easy to use management interface, we feel it's a great product. Moreover, considering that it's highly expandable, and can be used both as a NAS or a SAN, it serves as a one stop storage solution for SMEs.