For the past few weeks, I’ve been stress testing RAID devices for your entertainment and edification. Today, we’ll be looking at the fourth of seven NAS products to see how it performs.
Let’s put this project into context. The whole purpose of a RAID is that if a drive fails, you can recover with no data loss. In this series, I’m pounding on each NAS to see how (or if) it recovers.
Almost all the NAS reviews out there just talk about adding storage, and the various apps that come with the devices. I haven’t seen any that stress the machines to the point of failure and back to restoration, which is the whole point of these devices.
I’ve subjected each candidate machine to a series of torture tests. Beyond that, I look at performance, apps, user interface, and so much more. Today, we’re testing the Western Digital MyCloud PR4100.
Let’s get the bad news out of the way. The Western Digital MyCloud PR4100 failed Test 1, drive failure discovery. When I put in the bad drive, the system hung.
Since it isn’t possible to reliably simulate a drive failure with the drives in motion, I used a more structured test. I have, in my collection, a bad drive. It won’t boot, can’t be recognized by Windows, and is, not to put too fine a line on it, basically toast. It is the living embodiment of a drive gone bad.
This bad drive was used on each machine to simulate a drive failure. For each machine, I shut down the NAS being tested, removed the second drive, and replaced it with the dead drive. I then rebooted the NAS and waited to see what happened.
All the other NAS boxes eventually detected the bad drive. Not so much with the WD MyCloud. I waited 10 minutes, then 20 minutes. After an hour, there was still no visible indication on the machine, no buzzer, no email warning.
I powered the machine off, powered it back on, and I let the machine sit overnight. The next morning, it remained in its unresponsive state. The machine would not provide access to any other storage on the RAID. And the web interface would not respond.
I eventually removed the bad drive, installed my mismatched replacement drive, and rebooted the machine.
This brought me to Test 2, recovery to a mismatched drive. The WD performed flawlessly. Not only did it discover the new drive, it rebuilt the array automatically.
A few hours later, with pretty much no work on my part, the array was back in business….