So, I had a 1TB MyBook Studio II, and it seems that when one drive fails, the entire device stops working till the drive is replaced, which is NOT how RAID-1 is supposed to work. In fact, for anything critical this behavior makes the device basically useless. I have thrown the Studio II away, but now I am worried that a failure on my Thunderbolt MyBook will behave the same way, and that device is absolutely mission critical. I no longer trust these devices enough to just yank a drive and see what happens, so I am hoping that someone can verify that these Thunderbolt devices work as expected, or are they also worthless in a mission critical situation and it’s time to trash everything and move to an actual “professional” solution?
Please note that RAID 1 will do a copy of what you put on the first drive to the second one on the unit, so the unit will not work until you put a replacement drive to image the files.
As far as I know, all RAID 1 devices works the same way. If one of the drives fails, it will be degraded.
that may be the way Western Digital RAID-1 devices work, but it certainly isn’t how they have to work, or SHOULD work. As you say, data is written to both drives when both drives are present, but when done right, if a drive fails the device and remaining drive should continue to function in the degraded state, but without any redundancy (the meaning of “degraded”). When you get a replacement drive in place it will take some time to “rebuild”, catching up with the continuously available drive, including any data added after the drive failure. I have two 2-bay Synology NAS devices, and both work exactly this way.
I suspect I will pull a drive from my WD Thunderbolt device, and if it fails like this MyBook Studio then it’s in the garbage too and I am replacing it with a G|RAID or a similar professional quality device.