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webstyr

macrumors newbie
Original poster
Oct 12, 2014
5
0
I am presently running a Drobo S over Firewire 800 on my new cylindrical MacPro running Mavericks 10.9.5. The Drobo S is a 5-bay unit and I have almost filled it up with data. I have five 4TB drives in it now. I am stuck on deciding to move to a DroboPro 8-bay unit that connects using Firewire 800, or go with a standard RAID 6 8-Bay thunderbolt enclosure.

Pros and cons for the Drobo: Pro - It is dead simple and I've never had a problem with the three Drobos I've owned. Con - the maximum volume size is 16TB. Once you put more data than that on the drives it will create a 2nd volume. I only want one HUGE volume.

Pros and Cons for the traditional RAID 6 8-Bay enclosure: Pro - I can RAID 6 all 8 drives into one Huge volume, formatting with HFS+. Pro - Faster transfer rate. Con - The redundancy takes a lot more space than the Drobo.

I think that about gives you the big picture. If I've spoken out of turn, please correct me! I'm using this for my massive iTunes library which consists of over 4500 Movies, 200,000 Songs, 5500 TV Shows, podcasts and 110 Video Training Courses in iTunes U. I need just one massive volume because iTunes will only let you locate your iTunes library in one location.

Any help and insights into my dilemma would be greatly appreciated! Thanks for your help! :)
 

isomorphic

macrumors 6502
Apr 19, 2010
298
489
I wrote a long reply to this message, but the forum ate it. :( Sorry if this is terse.

On the subject of Drobo: I know it works for others, but it's not for me for a couple of reasons. It uses a proprietary on-disk format and has no rescue tools (short of buying another Drobo and swapping out disks). It "snoops" the filesystem you're using in order to make it's BeyondRAID work. That is, instead of being a dumb block device it actually has to understand the meaning of HFS--which is a problem if you want to encrypt your disks or if Apple changes HFS.

About iTunes: I have a very large iTunes library as well, and I am managing it with JBOD and a bunch of OEM hard drives plus a drive dock for backups. I do not use any hardware/software system to span the JBOD. iTunes does just fine if you turn off "Copy files..." in prefs, organize media yourself, and drag links into iTunes. You can even set aside one disk and have iTunes organize it by dragging things into "Automatically Add to iTunes."

Since my library does not change that much other than through additions, backups are relatively easy. Since I'm using OEM drives, backups are also cheap.

About RAID: RAID certainly has its place. But remember: RAID is not a backup. RAID is for availability. I'd avoid RAID-5 and go with RAID-6 for anything I really needed to stay online. But as you said, RAID-6 has overhead issues. For many use cases, RAID 10 is better.

Apple really needs a "unionfs" or LVM or Storage Spaces equivalent. CoreStorage looks like it's moving in the right direction, but I'm not sure Apple's customers need what I want, given that most of Apple's kit is consumer-oriented (phones with little storage), and most of their computer sales are of laptops (with little storage).
 

webstyr

macrumors newbie
Original poster
Oct 12, 2014
5
0
Thanks for all the good info. I have a few questions on your use of JBOD for iTunes. Do you just put them all in an 8 or 12 bay enclosure? Do you just duplicate each drive to another drive in your dock for backups? Or do you use Time Machine to back them up? I want to keep it as automated as possible so I don't spend all my time organizing and backing up.

I know Drobo and RAID aren't a back up, but with Drobo I didn't need one. All I had to do if a drive failed was pop in another drive and after it recovered, I was good to go. I never had to replace the whole disk pack or Drobo unit itself, only a drive when it failed. If Drobo would allow more than 16TB per volume I would not have a problem with it, but that limit is making things difficult for me, which is why I'm looking for alternatives. Using JBOD is certainly an alternative that I will explore more. Thanks for that!

I completely agree that Apple needs to get the LVM issue sorted, especially now that they have this alliance with IBM. It's going to become a bigger issue now and hopefully it will light a fire under them. :)
 

webstyr

macrumors newbie
Original poster
Oct 12, 2014
5
0
Just had another thought. If I got an eight bay enclosure, I could do a RAID 6 on four of the drives, and another RAID 6 on the other four drives. Then I could do a RAID 0 on the two RAID 6 elements to create a RAID 60. That way I would have the redundancy and some speed. What are your thoughts on that scenario?
 

mvmanolov

macrumors 6502a
Aug 27, 2013
858
5
Just had another thought. If I got an eight bay enclosure, I could do a RAID 6 on four of the drives, and another RAID 6 on the other four drives. Then I could do a RAID 0 on the two RAID 6 elements to create a RAID 60. That way I would have the redundancy and some speed. What are your thoughts on that scenario?

if i'm not mistaken you need at least 5 drives for Raid 6

also, why not take a look at LaCie's new thunderbolt rack mount raid box...
 

webstyr

macrumors newbie
Original poster
Oct 12, 2014
5
0
if i'm not mistaken you need at least 5 drives for Raid 6

also, why not take a look at LaCie's new thunderbolt rack mount raid box...

I just double checked on the minimum number of drives you have to have for RAID 6 and it is four. As for the LaCie solution, it fits everything I need except one thing, its not cost effective. It would cost $2,600 for a 24TB unit. I'm looking to do it for half that. If they sold an empty box it might be attractive, but they don't. :(
 

mvmanolov

macrumors 6502a
Aug 27, 2013
858
5
I just double checked on the minimum number of drives you have to have for RAID 6 and it is four. As for the LaCie solution, it fits everything I need except one thing, its not cost effective. It would cost $2,600 for a 24TB unit. I'm looking to do it for half that. If they sold an empty box it might be attractive, but they don't. :(

thanks for correcting me on the raid 6 :D

and yes i hear you on the cost element... though, some companies offer financing options for this: http://www.vistek.ca/store/StorageD...lt-2-rack-up-to-1330mbs-7200rpm-includes.aspx
 

sevoneone

macrumors 6502a
May 16, 2010
900
1,153
Just had another thought. If I got an eight bay enclosure, I could do a RAID 6 on four of the drives, and another RAID 6 on the other four drives. Then I could do a RAID 0 on the two RAID 6 elements to create a RAID 60. That way I would have the redundancy and some speed. What are your thoughts on that scenario?

Why use RAID 60 unless you absolutely need the additional redundancy of RAID 6? Wouldn't you get the same storage capacity and better write speeds with RAID 10?
 

SamEdwards

macrumors newbie
Mar 22, 2010
16
2
I found a great deal on a first generation Pegasus with 1TB drives. You can download the compatibility sheet and buy the 4TB drives that they recommend and reformat. It's a great system with amazing performance. I actually use two of these R6 units that are 20TB each in Raid5. I could further stripe them together and get even more performance, but with the risks that come with striping...
 
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