Dell bulks up storage appliance
Dell PowerVault MD3000i adds iSCSI to already solid applianceFollow @infoworld
Another smart feature of MDSM is the ability to easily switch from in-band to off-band management, which obviously gives administrators the flexibility to start the GUI from wherever it’s most convenient.
Assigning each virtual disk to one of my application servers was easier than it usually is with iSCSI. The array comes with a host agent that simplifies linking each iSCSI initiator to its target. After installing each agent, MDSM automatically discovered the new host and left me to make the connection to the appropriate virtual disk. As an additional bonus, from MDSM you can easily keep an eye on the storage used by each server.
Dell suggests that you can connect as many as 16 hosts to the MD3000i, but don’t expect top performance concurrently on all of them. After running a few benchmarks simulating I/O-intensive transactional access from my four application servers, I was convinced that the array can take more. However, the four GigE connections could become the bottleneck if you run numerous concurrent, data-intensive jobs such as backups.
One thing I didn’t like: MDSM doesn’t have load-monitoring applets. However, the array keeps cumulative statistics of the traffic on each iSCSI port that help in spotting a persistent load unbalance. Another annoyance: the appliance serializes some operations if they are logically dependent. For example, while creating a snapshot for a virtual disk, a message stopped me because there were not enough physical drives in the storage group. I added the drives, but still couldn’t create the snapshot until the previous operation, often a long one, completed. To be accurate, the GUI lets you continue immediately if you accept creating the snapshot in a different disk group, but it would be preferable to let the admin schedule the job anyway and put it in a queue until the previous one is finished. By contrast, it’s difficult to find anything wrong with the resilience characteristics of the MD3000i. After pulling out a drive, removing one of the controllers and one of the power supply modules, my test job was still running.
If your servers and your network are properly equipped, that host agent also brings multi-path capabilities. Moreover, the array has 1GB of mirrored, battery protected cache that helps to boost performance and shelters data from sudden power shut-offs.