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sdardens

macrumors newbie
Original poster
Nov 30, 2012
2
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I would appreciate advice on a backup solution so we can safely abandon our "sunsetted" but beloved Mac Pro for a Mac Mini. What I think we want is a 4-bay USB3 (Thunderbolt) enclosure/dock for 3.5" SATA. So long as we can fit everything on a single spindle I don't want RAID, just 4 independently mounted drives - but requiring only a single USB port (or Thunderbolt of course).

A possible solution is the StarTech 4 Bay eSATA USB 3.0 to SATA Hard Drive Docking Station for 2.5/3.5 HDD.

Here's the simple, reliable backup strategy we currently use on Mac Pro. It uses four 1 TB drives as follows:

Drive: function
1: boot and all data
2: nightly bootable clone
3: nightly bootable clone
4: Time Machine backup

The clones are automatically generated every night by SuperDuper! using Smart Update, about 20 minutes for 700GB.

A single RAID 5 scheme will not protect our data as well as simple redundancy, unless we invest in a backup scheme for the RAID. And the folks who are serious about large data security require at least a redundant pair of RAID 5 so that gremlins in the RAID don't take down the system. Plus backups of the RAID.

So in addition to the complexity and elapsed time required to deal with RAID drive faults and upgrades, then we have to have more hardware and procedures to assure overall reliability. If we needed zero-downtime performance the RAID would be justified. But our requirement isn't zero downtime it's to be rebooted and running again in 5 minutes or less. If we have to recover the last few hours of changes via TimeMachine that's not an issue.

Any thoughts, recommendations would be much appreciated!.

PS- please don't recommend Drobo RAID. Sounds great, but bad things can happen making the whole stack useless.
 
It sounds like you want a JBOD (just a nunch of disk) system. The problem with your Startech and many 4-5 bay USB 3.0 eSATA enclosure is the fact that they
require a port-multiplier eSATA. Just look at the specs:
http://www.startech.com/HDD/Docking...ive-Docking-Station-for-25-35-HDD~SATDOCK4U3E

Port multipliers will allow you to see those 4 disks as 4 different disks. I have a few USB 3.0 to eSATA (NewerTech, StarTech) and none of them support port multiplication.


If you want to go the USB 3.0 only route, the other problem you will have is many of the cheap, low-end 4-bay eSATA boxes will suffer from controller incompatibility. A majority of them run outdated JMicron controllers
which is problematic with certain USB 3.0 chipsets. This results in intermittent drop connections, sleep isssues. disconnects, corrupted data. These problems show up as 1 star customer reviews on Amazon and NewEgg. Companies like SansDigital and MediaSonic have the message board filled with complaints.

I understand your need for redundancy but a 4 bay USB3/eSATA solution like the one above "may" not work. You are better off getting a USB 3.0 hub with 4 external drives connected and continue with your existing workflow.
You can look into the LaCie Thunderbolt eSATA adapter. I don't know if that has port multiplication but that is something to look at. If you can get port multiplication to work (via Thunderbolt), then those $99-$200 4 bay eSATA only enclosures may work for you.

I personally would do an OWC Mercury rack RAID. They go for $300 something. Get two of them and run them in pairs.

Then I would relegate an older mac to run synchronization in the background to a 3rd set of drives. This could be a big USB 3.0 4TB drive (or multiple drives). Re-purposing old Mac (G5, even old G4 minis) is a smart thing to do. Set up a cron job, SSH keys and run rsynch with -E flag (for maintaining HFS mac attributes). So if the Mac Mini dies, you can have another machine already up-to-date and ready to go. It may not be the fastest but it is ready to go. I have set ups like this all the time. Syncs happen every 15 minutes over the network.

I do these things all the time. From 4TB to 60TB worth of data. Low-end to high end 30 disks SAS RAIDs and everything in-between.
 
You are better off getting a USB 3.0 hub with 4 external drives connected and continue with your existing workflow.

Ditto this suggestion. Most of the 4-bay units that support Thunderbolt are very pricey, and include RAID features that you're paying for but don't need in your application. The USB 3.0 multi-bay units are also either pricey, or prone to the issues @fortysomegeek alludes to (JMicron problems, etc).

You can get a USB 3.0 hub and four USB 3.0 enclosures or docks, spend less than you would have on a single chassis, and have fully redundant power supplies & interfaces for each disk.
 
Thanks heaps for your very detailed guidance. My apologies for the slow followup. We are cruising in the South Pacific aboard our yacht - so there some issues with internet access.

BTW, one motivator for switching to Mac Mini is to slash power consumption. We call the Mac Pro "the space heater":)

It sounds like you want a JBOD (just a nunch of disk) system. The problem with your Startech and many 4-5 bay USB 3.0 eSATA enclosure is the fact that they require a port-multiplier eSATA.

Yes, JBOD. As I read the specs and customer comments I think Startech has included port multiplication for USB. E.g., see Amazon

http://amzn.to/10JCxSr who writes

I use this product with the USB 3.0 connection into a 2012 Mac Mini. I get speeds of around 80MB/sec which are acceptable. Others may have touched on this but I want to make it explicitly clear that you MUST dismount all drives before removing or adding any drive. When you remove or add a drive the system treats it as though you disconnected all drives. If you have data transfer of any type (time machine, etc) it will fail and data will be corrupted. Other than that, this gets the job done.

And I have just emailed Startech for confirmation on port multiplication, dismounting issues, etc.

You are better off getting a USB 3.0 hub with 4 external drives connected and continue with your existing workflow.
Thanks. And as FreakinEurekan points out below, the single-failure-point supply is eliminated. I will investigate both the hub and Thunderbolt eSATA adapter. I have read success comments on the latter.

Re: the power supply common failure point, if we go with Startech or similar I will buy a second unit and store for a spare supply/controller.

Then I would relegate an older mac to run synchronization in the background to a 3rd set of drives.
Understood. I would definitely consider that if we lived on terra firma. But we are really trying to simplify, reduce weight and clutter. So everything except our Cinema Display/keyboard needs to fit in our "computer bay" with no extra cooling.

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You can get a USB 3.0 hub and four USB 3.0 enclosures or docks, spend less than you would have on a single chassis, and have fully redundant power supplies & interfaces for each disk.

Thanks heaps - good points and motivation. As I wrote in reply above I'm investigating the hub scheme. And the Thunderbolt-eSATA.
 
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