Wednesday, June 18, 2014

RocketStor Drive Dock: More Expensive But Reliable

I previously mentioned the Highpoint RocketStor 5212 (Amazon), which is a dock for dual 2.5- or 3.5-inch hard drives that connects via Thunderbolt. USB 3 has always seemed plenty fast to me for backups, so I initially dismissed the RocketStor and its high price. However, I continued to have problems with hard drives spontaneously unmounting during backups. This would, at the least, interrupt hours of work, and at the worst corrupt the data. In some cases, the only way to complete a backup was with multiple passes of SuperDuper’s Smart Update, each one copying a different set of files before failing, until finally all were copied.

The problems occurred with both the NewerTech Voyager S3 (Amazon) and the Anker USB 3.0 Hard Drive Docking Station (Amazon). It occurred with multiple Macs, multiple (of each) drive docks, multiple hard drives of different capacities and brands, multiple backup apps, multiple uninterruptible power supplies (as well as none), with and without any other connected USB devices (including hubs), and in multiple buildings.

I reported the problem to the manufacturers, who seemed not be aware of it, and received replacement drive docks, which didn’t work any better. I also got some recommendations for other brands, although the Amazon reviews did not inspire confidence.

I still don’t know what’s causing these problems, nor why they only affect some users. However, my hypothesis is that it’s related to USB 3. There may be a bug in the Mac OS X driver, although I’ve seen similar reports from Windows 7 users. Perhaps the bug is with the USB 3 on the docks themselves. In any event, every USB 3 drive dock I’ve tried has had the unmounting problem, and none of my older USB 2 drive docks did. (Unfortunately, USB 2 drive docks are much slower and only support capacities up to 2 TB.)

The obvious solution was to try a drive dock that doesn’t use USB 3. This brought me back to the RocketStor, whose price has come down from $219 to $190. Result: through many hours of backups as well as regular use, the RocketStor has never spontaneously unmounted a drive.

The RocketStor has some other good points:

I also found some problems:

All of this is to say that I consider the RocketStor a flawed product, but I’m grateful to have it because once a drive is mounted it stays mounted. Sadly that seems to be a lot to ask of a storage product these days.

Update (2014-06-23): There’s a 62-page thread in the Apple support forum about disks ejecting themselves (via Brian P. Hogan).

Update (2015-05-08): The price at Amazon is now down to $147.

10 Comments RSS · Twitter

Yes, you can connect more devices, as long as they have passthrough ports.

@Jesper Yes, thanks for clarifying. The important point for me is that you can’t connect two RocketStors.

[…] If you connect the Belkin to a MacBook Air, a display, and a single drive dock, you’re already out of Thunderbolt ports. And three USB ports is barely any. I’m […]

[…] Keyboard aside, it sounds nice for what it is. It’s not for me, though. After the 12-inch MacBook was announced, I bought an 11-inch MacBook Air to use as an auxiliary Mac. It’s small enough to fit on the desk next to my main Mac, much faster than the 12-inch MacBook, and has a Thunderbolt port for connecting my drive dock. […]


I have been having the same problem. For the past three months I have been used the RocketStor 5212 thunderbolt dock and four times times my drives have spontaneously unmounted and my data was corrupted (same files each time...luckily I am backed up).

I never had this problem when working with Firewire 800 and the NewerTech Voyager Q.

This is very time consuming and nerve wracking. Do you think this is caused the dock or the OS? Is there a possibility that there is something wrong with my files?

@Jon I have never seen that problem with the RocketStor and Thunderbolt. With USB 3, I think it’s caused by an OS bug.

[…] rewritten USB stack in El Capitan would solve the problem I’ve been having with USB 3 drives spontaneously unmounting. However, that is not the case. One of my drives unmounted in the middle of a backup literally […]

I have seen this too with multiple Macs (2014 15" MBP, 2015 Retina 5k iMac) running 10.10 and this Inateck 3.5" enclosure:

I have the same unmount issue with this dock. The only way to bring them back is to power down the dock.

I suspect that it can have many reasons to disconnect drives "randomly", but no proper error reporting is implemented.

[…] unmount my drives. Previously, the only reliable dock I’d found was the Thunderbolt-based Highpoint RocketStor 5212. At $69, the OWC is less than half the (now reduced) price of the RocketStor and only $20 more than […]

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