A big selling point of the 150d is its RAID capabilities, allowing users to make a choice between performance and data security. By default, the device comes configured with RAID 5, which is a reasonable choice for most uses. Under RAID 5 all of the disks are combined into one large logical drive. The space equivalent to one disk is reserved for parity information to support single disk failure recovery. If a single disk dies, you just pull it out and replace it which causes the system to automatically rebuild the system without data loss.
To test this feature, I pulled a drive out and replaced it while the system was up and running. When I pulled the disk out, its associated LED went out, the power LED started blinking red and the system status as shown in the Disk Management screen was listed as "Degraded".
When I plugged the drive back in, its LED went back on and the power LED continued to flash red. During this period, the Disk Management screen gave a status of "Rebuilding", and gave an estimated time to completion. Rebuilding took just under two and a half hours. As far as alerts, I received an email alert when the disk was pulled, and another when it was replaced, but I did not receive an email when the rebuild was complete.
As you can see in Figure 11, three other RAID levels are supported by the 150d.
Figure 11: RAID Support
Spanning combines all of yours disks into a single share, making them look like one big drive. Striping also combines all of the disks into a single share, but it does parallel reading and writing, giving increased performance with no data recovery possibilities. Mirroring does what it sounds like: all data is automatically written to two drives, creating data redundancy, but cutting capacity in half.
Other disk management features include the ability to set the spin down time for the disks. Figure 12 shows the Disk Management menu where the spin-down time can be set, the health stats of the drives is shown, and an option for USB- attached drives can be set.
Figure 12: Disk Management
Be default, when a USB drive is plugged in, it gets mounted and exported as a share. Iomega documents support for USB disks formatted in FAT, FAT32 or NTFS in a read-only mode.
One of the main uses of a device like this is for backup. To this end, Iomega includes two licenses for EMC Retrospect Express, a backup package that can be installed on both Windows and Apple computers. This type of backup is a push from clients to the 150d. It might have been nice to see a "pull" backup as well where the 150d would mount a network share and then copy it to a specified directory.
In addition to acting as a destination for backing up client computers, the 150d has the ability to back itself up to either an external USB drive or to another 150d located on the network. Figure 13 shows the menu that allows these backup jobs to be defined.
Figure 13: Backup Creation
As you can see, the jobs can be scheduled various ways and can be complete or incremental backups.
After I had explored the administration menus, there were a few things I didn't see. First, there was no logging capability. I like to see some level of logging so I can tell what is happening in the box. In addition, I'd like the ability to check the SMART status of the drives for preventative maintenance purposes.
The last thing I didn't see was any firmware update capability. Typically on these boxes, you'll find a menu item where an updated firmware image can be loaded. When I dug a bit deeper, it appears as if updating the firmware requires running an executable on a Windows box. This is a bit of a downside for people running Linux or Macs.