RAID or JBOD

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Level 1

4 points

RAID or JBOD

I just received a WD MyBook Thunderbolt Duo for Christmas 4TB (x2-2TB). I am spinning my wheels when it comes to initial set up. I want to get it right the first time and this is my first go 'round with an external drive.

My primary focus is to move my iMovie, iTunes and potentially my iPhoto library off my mac to the external drive. My 1TB drive on the Mac is nearing capacity. Secondary focus will be to use the MyBook as a back up via Time Machine. So, what best suits my needs? I have talked myself into and out of all possible options... This is my ONLY back up option at this point. I have never backed my Mac up, and have been dang lucky up to this point. However, I'm done being lucky. BUT I can not afford another Thunderbolt drive at this point.

So, here's where I stand. Any advice or real world answers to the questions therein will be greatly appreciated.

RAID 0 - Performance seems great based on what I've read. However, the fear of losing one drive then losing ALL the data does not seem worth it to me. What are recovery rates like for data that is lost?

RAID 1 - I love the back up idea and I am slightly leaning toward this option.

JBOD - This option is #1 in my opinion. However, I am wondering what the performance will be in this set up. Basically, did I just by a Cadillac to just let it sit in the Garage?? My plan is to use 1 drive as storage and 1 drive as back up. Will I get good enough performance to use my storage drive as my main drive for Video files?

Thanks in advance!

iMac (21.5-inch Mid 2011)

Posted on Dec 29, 2014 4:04 PM

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Answer 1

Old Toad

Level 10

215,346 points

Dec 29, 2014 4:11 PM in response to DragynJ

If you plan on running an iPhoto Library from an external HD it must be formatted OS X Extended (journaled) otherwise the integrity of the library's structure will be damaged.

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Answer 2

DragynJ Author

Level 1

4 points

Dec 29, 2014 6:36 PM in response to Old Toad

Good point. Both drives are already formatted as such.

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Answer 3

chinajon

Level 1

63 points

Jul 23, 2015 8:10 PM in response to DragynJ

As an aside, consider partitioning one of the drives and use a partition as your backup drive for TimeMachine. Over time, TM will use up all available space in whatever drive it is in. So, give it a partition that is only for backups, and use the other partition for daily use.

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Answer 4

Old Toad

Level 10

215,346 points

Jul 24, 2015 9:00 AM in response to chinajon

Doing that will put the daily use partition at risk as it won't have a backup. If that drive crashes the TM backup volume will be lost along with the daily use volume. It's best to have to drives, one for daily use and one for TM which backs up both the internal boot drive and the external daily use drive.

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Answer 5

DragynJ Author

Level 1

4 points

Jul 24, 2015 9:13 AM in response to DragynJ

I never did close out what I did, for those interested...

I did end up going Raid 0. I tested disk speed and the performance was just too good to pass up! I moved my iMovie and iTunes libraries off the Mac and started Time Machine on the External drive. 2mos after doing so, my Mac crashed.... Thank God I had done the back up, lost NOTHING!

I am concerned that TM will be like a fat kid with cake and fill that external drive up though.... I need to go through the settings and see what I can do to limit the amount of back ups I have saved. I haven't spent a lot of time learning about TM, need to do that soon.

I have quite a bit of old stuff on this computer to delete. I'll clean house, then worry about space. If push comes to shove I'll get another external and daisy chain everything together and build from there.

Thanks for the advice!

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Answer 6

rkaufmann87

Level 10

148,458 points

Jul 24, 2015 9:17 AM in response to DragynJ

Time Machine will eventually fill any drive however it is smart enough to delete the oldest backups, therefore the drive is always useable for backups assuming it is mechanically okay. Read up on Time Machine to learn how it works and you will understand more.

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Answer 7

Arimaguy

Level 1

4 points

Jul 24, 2015 5:08 PM in response to DragynJ

I just went through the same decision process while setting up a new iMac system. I orginally bought the Thunderbolt Duo to use in RAID 0 configuration primarily for a video rendering target drive. Once I had all the boxes of new kit I changed my mind and set it up in RAID 1 for Time Machine. It is performing perfectly in that capacity.

Now I have another decision to make for my rendering drive. Get a smaller capacity SSD drive or get another Thunderbolt Duo to use in RAID 0? Cost is the same for a new 256GB Thunderbolt SSD or a referb Thunderbolt Duo.

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Answer 8

chinajon

Level 1

63 points

Jul 24, 2015 8:10 PM in response to Old Toad

If the drive crashes then the TM backup would be lost in any case whether the drive was partitioned or not.

Partitioning the external creates two logical drives. It is possible that a drive error could corrupt the free partition, But if the free partition is used only for a workspace, backup is not so important. Data could be recovered in the old fashioned way with a Data Recovery App.

The goal is to limit TM and free up space on the external. The internal 'daily use' drive would not be affected.

Today, multiple terabyte drives are affordable, but the huge space is not needed by TM.

In fact one 4TB drive could be divided into four 1TB partitions, and need only 1 cable for the connection. 4 separate 1TB drives would probably need powered hub, along with 5 cables, one to the Mac and 4 to the drives.

Partitioning is a very sensible alternative.

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