Thecus N3200XXX NAS Server ReviewNemo - October 6, 2011
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RAID 1/5 Data Protection
The N3200XXX supports up to three drives giving it the ability to support RAID levels 1 and 5 that afford a level of redundancy in the case of a single drive failure. Thecus also touts its server as having 'Extreme Protection' leading one to expect the unit to keep your data available, as well as provide some level of recovery. That proves to be the case with RAID 1 protection on the N3200XXX, which requires two drives, also offering you the option of designating the third drive as a hot spare. The N3200XXX also supports RAID 5, which requires at least three drives, but can keep data available in the event of a single drive failure.
We'll test the ability of the N3200XXX to recover from a single failed drive in both RAID 1 and RAID 5 configurations. For both configurations, I simulated a 'failure' by removing a disk drive from the unit while powered on. Since the server supports hot-swapping drives, you can remove and replace drives without having to power the unit down.
With the RAID 1 test, I created a volume using all three drives, but since RAID 1 uses only two drives, the third drive automatically becomes the hot spare by default. With Disk 1 removed to simulate the failure, the volume is showing a Degraded state and in the lower left corner, the volume and disk icons are red, indicating a problem. By the time I placed Disk 1 back into the server, the system had already begun the rebuild process using Disk 3 as the hot spare. We can see that Disk 1 now automatically becomes the hot spare as only two disks are used in a RAID 1 volume. Several hours later, the volume is rebuilt and back to a healthy status. The N3200XXX automatically began the rebuild process using the designated hot spare and the volume was returned to normal without loss of data.
Again with the RAID 5 test, I formed a volume using all three drives. Since RAID 5 requires a minimum of three drives, we could not test with the auto-rebuild using the hot-spare. After removing Drive 1 to simulate the failure, the volume went into degraded mode and once the drive was replaced, the auto-rebuild process began, resulting in a healthy volume some fourteen plus hours later.
With both scenarios, removing a drive from the box caused the corresponding hard drive light on the front of the unit to turn red, indicating there was a problem. Additionally, with notifications enabled, I received a stream of e-mails letting me know that the drive had failed, the volume was in degraded mode, that the volume was being rebuilt, and a final message when the rebuild completed and the volume was healthy again. The N3200XXX certainly lived up to its 'Extreme Protection' claim and was able to successfully recover from a drive failure in both RAID 1 and RAID 5 modes, while keeping the data safe in the process.
You can expand the capacity of an existing volume by allocating unused space to the volume. Back in the Storage configuration page, we looked at the RAID Management section and saw how to build a RAID volume. In the example here, I built a RAID 1 volume, but did not allocate all the drive space to the volume. In fact, only about half of the available space was dedicated to the RAID volume. When we click on the Edit button, we see there is an Expand tab also available. Clicking on that brings up the Expand Capacity slider, which we can use to determine the additional space available and how much to add to the exiting volume. You will get a couple of warning dialogs when you press the Apply button before the expansion process starts.
During the process, the Status columns displays 'Expand RAID' and you will need to wait until the process completes, after which it will show the additional space in the volume. Another way this capability comes in handy is when you want to expand the capacity of the unit by adding larger-capacity drives. You can replace the drives one at a time, wait for the volume to rebuild after each drive is replaced, then expand the volume using the new space.
RAID migration is the process of changing, or migrating, a volume and its data from one level of RAID to another. There are several directions you can migrate in when it comes to different RAID levels, but the reality is, on the N3200XXX with three drives, the only available option is to migrate from a RAID 1 two-drive volume to a RAID 5 three-drive volume. For some odd reason, the N3200XXX UI also offers a RAID 1 – RAID 6 option, which is physically impossible, since RAID 6 requires four drives and we only have three drives in the N3200XXX.
To migrate the RAID from one level to the next, you need to highlight the volume in the Storage/RAID Management window and click the Edit button. From there, you click on the Migrate RAID tab. Here the system will present the RAID Level options available to you, which is limited to 'RAID 1 → RAID 5 (Online)', make sure to check the box next to Drive 3 to add it to the RAID 5 volume and then press the Apply button. You'll receive the obligatory dialogs telling you it could take a long time and warning you about the potential for data loss.
Once you agree to the warnings, the migration process begins and the systems switches from the two drives used in the RAID 1 array to a three-drive RAID 5 volume and the build process begins. This was a rather lengthy process taking over eighteen hours to complete. In the end, you're left with a healthy RAID 5 volume with all your data intact.