IBM Storwize V7000

This is the latest addition to IBM's storage portfolio, for organizations looking to consolidate their storage into a single, scalable, and virtualized SAN disk-array for their mission critical business apps, be it SAP ERP, MS Exchange, VWware virtualization, etc.

The good thing about this storage system is that it has inherited quite a few enterprise class features from IBM's earlier generation storage systems, namely the SVC (SAN Volume Controller) and DS8000 RAID. And, it has added several new features apart from those.

Key Features

Some of the inherited features include support for FCP, iSCSI, and even FCoE (Fibre Channel over Ethernet); storage virtualization, FlashCopy, Thin Provisioning, and Real Time Compression. RAID levels supported include 0, 1, 5, 6, and 10. The enhanced features include a new and improved GUI for better manageability, easy tiering, integration with IBM's Systems Director, and various enhancements in scalability, interoperability between Host, Controller, and ISV, etc.

Some other features of this SAN box include two RAID controllers, non-disruptive migration and built-in SSD optimization. The compact 2U form factor chassis of V7000 has space for up to 24 Serial Attached SCSI (SAS) hard drives. The storage device supports both 2.5 and 3.5” drives and can take SAS, SSD, and NL-SAS drives. Max capacities supported include 3 TB 3.5” NL-SAS drives and up to 900 GB of 2.5” SAS disks. Each of the controllers has 8 GB cache RAM, and two Gigabit LAN ports, both of which can be used for iSCSI. There were also 4x8 Gbps Fibre Channel ports and two USB ports. Plus there are SAS expansion ports for daisy-chaining up to 9 Storwize expansion enclosures. Moreover, you can further scale out and build a cluster by putting four storage controllers together. This translates to ample scalability for your storage requirements. Moreover, the internal storage in each disk enclosure can be a mix of SSD, SAS, and NL-SAS drives, and you can set them as different RAID configurations, allowing multi-tier storage to be created in the same box.

Presence of two battery-backed load balancing power supplies is another important feature. So if (God forbid!), both power supplies fail, this will keep the unit going long enough to do a proper system shutdown.

There is one feature that this storage solution doesn't support, which is de-duplication. The rationale for not supporting de-duplication, according to IBM, is a built-in strong compression feature that is able to compress your data by 50-90%. So you end up saving as much disk space as you would have if you used de-duplication, and all this without too much performance degradation. Moreover, this compression happens in real-time.

The Setup

Setting up the V7000 is pretty straight forward. You connect the two power cables (main+failover) and the necessary data cables. For data we have option for both fiber (depends on your storage switch) and Ethernet connectivity. In our test setup, we connected Ethernet cables directly to a server running Windows Server 2012, and the data transfer was carried out on iSCSI protocol.

If you want to access your V7000 even before initializing it, you can do so using default service IPs assigned to the Ethernet ports located on both controllers. The storage unit ships with a USB flash drive containing an initialization tool, which needs to be plugged into a Windows PC. This lets you initialize a new Storwize V7000 (block system only), and assign an IP address to the SAN. Once that's done, you need to plug the same USB drive into the V7000 unit after switching it on. A couple of amber LEDs next to the USB port start flashing for some time. Once they stop, your SAN box is ready for use and can be accessed over the assigned IP address.

The unit that shipped to us had by default a basic RAID-5 array on 8 SAS drives. The SAN's GUI is very user friendly and one of the best we have ever come across. It presents you with a logical diagram in the overview window, which tells you about the number of drives and external storage systems present, how these resources are grouped into pools, how many volumes are taken out from storage pools and finally how are volumes connected to hosts (or server).

Navigation through V7000 interface is quite simple with left panel providing all necessary options. Such kind of a GUI design lets you move to desired pages with a single click. Moreover, the web interface provides all necessary help resources including help documents and videos.

Performance

We used IOmeter to check the storage box's performance. We created a storage volume and added one iSCSI (Ethernet based) host to it. Our host was running Windows Server 2012 as indicated earlier. We used a single dedicated physical connection from the storage to the server. To give a comparative perspective, we ran IOmeter tests on two types of disks, one on storage volume (SAS disk @ 10,000 RPM) and the other on a local SSD disk.

We ran four tests on each disk using a single worker. Four different scenarios were used in our sample test, which included 10 MB maximum disk size with default 2 KB and 64 MB payload and random disk size with the same payload sizes. We kept all other settings default which means 67% read, 33% write, 100% random non/sequential writes.

As you can see from the test results, the performance over SSD is far greater than with SAS drives. What this means is that you can configure this storage unit for auto-tiering and move frequently accessed data onto SSDs and less frequently accessed to the SAS drives.

Bottom Line: With simple setup and great performance, this device is highly recommended for organizations looking to consolidate their storage into a single storage solution.