Drive Pull Test
We always perform a drive pull test on RAID-capable NASes to see exactly what will happen. For the F2, I started a directory copy on one computer while the TimeMachine backup was still being performed by my Mac. I pulled disk 1. There wasn't a beep, but the HDD1 light went out. Within about 10 seconds or so, I received the email notification shown below.
TerraMaster F2-NAS 2 disk failure email
It wasn't very detailed, but it gave me the idea that something bad had happened. The message, cryptic by any measure, certainly lacked the plain language email that other NASes use to indicate a drive failure or drive removal. The good news is that the both the directory copy as well as the TimeMachine backup continued to run without dropping any data.
The main login page also didn't indicate a problem with the disk array, either. However, the Hard Disk Group menu, shown below, indicates the status as High risk.
TerraMaster F2-NAS 2 Hark Disk Group showing RAID 1 array at high risk
Recovering from a disk failure in a RAID configuration is uncharted territory for the user guide, so I decided to just plug the drive back in and see what happened. The device is, after all, rated as hot swappable. The TimeMachine backup paused and the HDD2 LED (the one that was still running) turned red. Then the HDD1 light turned red, followed by both LEDs turning pink. Finally HDD2's LED turned blue and started flickering as the TimeMachine backup resumed. Apparently, TimeMachine waited patiently for the 30 seconds or so that it was interrupted. For the disk re-insertion, I did not get an email notification.
The Hard Disk group showed an uninitialized disk and said to create a new disk group. However, to create a new disk group, I would have had to delete the old disk group along with all of the data. I decided to click on "Repair" to see what happened. A pop up box appeared giving me the option to select Hard disk 1 (the one that I had re-inserted) and click OK. This seemed like a better option. Immediately, HDD1 was added back into the RAID 1 disk group, and the array synchronization started.
I'm not sure how long it took to synchronize, as I had to leave the office while the synchronization was running. I'm assuming that it took quite a bit longer than when I initialized the array, as the TimeMachine backup was continuously writing data while the synchronization was in progress. As a reference point, it was 42% complete after 104 minutes. the image below shows the uninitialized disk along with the repair option I selected.
TerraMaster F2-NAS 2 RAID repair
Starting with this review, we have switched to a new NAS Test process. The Revision 5 process uses the same Windows Filecopy and Intel NASPT benchmarks as our previous process, but a new Intel i7 / Windows 8.1 testbed machine that also includes dual 10 GbE NICs.
The results for products tested with Revision 5 will vary slightly from the results created using Revision 4 and therefore are not directly comparable. Products tested with Revision 5 use a new, dark gray bar as compared to the lighter gray bar used for Revision 4. For all but the top performing model NASes, you should expect similar results from which you can draw relative performance conclusions.
The chart below is the benchmark summary for the TerraMaster F2-NAS 2. Windows File Copy tests in the Benchmarks summary below show read throughput 26% higher than write for RAID 0 (66.2 vs. 52.4MB/s) and also about 29% faster for RAID 1 (58.1 vs. 45.2 MB/s). Similarly for both read and write tests, RAID 0 held an edge over RAID 1 results. For read operations, RAID 0 was about 14% faster than RAID 1 (66.1 vs. 58.1 MB/s) and for write operations, the margin was about 16% (52.4 vs. 45.2 MB/s).
Window File Copy results were faster than NASPT File Copy results for both the corresponding RAID 0 and RAID 1 Tests. For RAID 0, Windows File Copy readwas 60 % faster (52.4 vs. 32.7MB/s). For RAID 1Windows File Copy write was 95% faster than the NASPT RAID 1 file copy to NAS (45.2 vs. 23.1MB/s).