Small-stature Isilon IQ 200 file server packs big features
System compensates for power-supply shortcoming with great manageability and resilienceFollow @infoworld
Next I connected each server to its own directory by mapping a new network drive in Windows Explorer; nothing new to learn there. Then I launched a script on each machine to populate the new drive with files.
OneFS has many powerful features that you won’t find in conventional NAS systems. For example, the file system will automatically balance the space used across its nodes, such that each one will have a similar amount of free space. To improve performance and reliability, files are automatically striped across nodes and volumes in the cluster. In addition you can increase resilience by setting a different parity level up to four. This makes your files capable of surviving many hardware failures.
These additional parity levels apply to the whole cluster and can consume performance and capacity quicker, but OneFS has an advanced setting that makes possible different protection levels for the whole cluster, for each folder, and for each file.
OneFS offers an unlimited number of snapshots for each cluster driven by a schedule that gives great flexibility. For example, I was able to set different timing for each server’s folder and to position snapshots only one minute apart, which obviously minimizes the possibility of data loss.
I wasn’t able to try that feature with a single cluster, but OneFS also offers a synchronous replication option that can add disaster recovery capability to its excellent local recovery features.
Conveniently, all the knobs to control these applications are inside the two management interfaces, both the CLI and the GUI. The UIs also deliver tools to monitor the conditions of the hardware, access the alerts log, and read the status of components inside the enclosure, down to the SMART (Self-Monitoring, Analysis, and Reporting Technology) info for each drive.
I also loved the comprehensive set of performance monitoring tools, which allow you to analyze what’s happening on the whole cluster, on a single node, or on one drive.
Although I had planned to test how well the IQ 200's data protection features worked, I did not have to simulate a failure -- one happened naturally. A node refused to power back on after I had loaded all my test files and shut down the system for the day. The culprit was the power supply, which is a nonredundant component on the IQ 200.
I still had a spare node in stand-by, so I added it to the cluster and crossed my fingers while the system began healing itself. It took close to nine hours to redistribute almost 2TB of data, but all my files were there intact. In fact, I kept a movie clip running all that time and never noticed a hiccup.
It’s important to understand that by default, OneFS assigns a low priority to those housekeeping activities, but you can throttle the priority higher to speed up the healing process. However, during that time, I had normal access to my files, with some occasional hesitations when opening a file or changing a drive mapping on a server.
How fast is an IQ 200 cluster when not rebuilding? That varies, depending on how many nodes you have. More nodes add more spindles and more GigE ports, hence more bandwidth. The level of protection you choose also has an impact on performance, because it adds I/O operations to build the additional data redundancy.