RAID array on 3 identical drives with partition good?

Discussion in 'Mac Pro' started by imacdaddy, Jan 30, 2008.

  1. imacdaddy macrumors 6502a

    Joined:
    Feb 2, 2006
    #1
    Questions to the geniuses of MR:F. I've tried to piece together answers from other numerous threads but can't find the specific answers I need.

    First, I can't find the Samsung F1 320GB 16MB HD322HJ anywhere and was going to dedicate this as my OSX and Apps drive and 2 x 750GB F1 in RAID0 for data and scratch. So instead, I'm thinking of buying 3 x 750GB F1 and do software RAID0 on the 3 drives (I've got a 500GB external LaCie for backup). I plan to use only SW RAID and I don't plan to by Apple's HW RAID card. The stock 320GB drive will be used for bootcamp to Windows.

    Some background. For my freelance work, I do a lot of photo post processing and video creation/editing using Adobe CS3 so I need scratch disk and storage. Also, I rip my DVDs, encoding and re-encoding videos for my AppleTV & iPhone/iPod etc.

    Questions:

    1. What would be the "optimal" setup in terms of disk array and partitions for what I do?
    2. Would I be better under 1 x 750GB for OSX/Apps and 2 x 750GB in RAID0 with partitions for files and scratch?
    3. Would I be better under 3 x 750GB in RAID0 and with separate partitions for OSX, apps, files and scratch?

    Your feedback is greatly appreciated! :)
     
  2. kittiyut macrumors regular

    kittiyut

    Joined:
    Oct 28, 2007
    #2
    Your scratch disk should be on a separate PHYSICAL disk from your OS/system/programs for optimal performance. Hence option 3 would not be a good idea. Option 2 would be better.
     
  3. imacdaddy thread starter macrumors 6502a

    Joined:
    Feb 2, 2006
    #3
    Thanks for the feedback. Would using the stock 320GB which I plan to use for bootcamp to Windows be another solution to use as a scratch disk and keep the RAID0 on 3 x 750GB for my OSX/Apps/Data?

    ie.

    1) 3 x 750GB in RAID0 and partitioned for OSX/Apps/Data
    2) 1 x 320GB for bootcamp to Windows and Scratch


    Or will I benefit from the speed if the scratch is on a faster drive, and hence Option 2 would be better? Which means,

    1) 1 x 750GB for OSX/Apps
    2) 2 x 750GB in RAID0 for Data and Scratch
    3) 1 x 320GB for bootcamp to Windows
     
  4. scottydawg macrumors 6502

    scottydawg

    Joined:
    Jan 22, 2008
    Location:
    Sacramento, CA
    #4
    Sorry to hijack the thread but would you mind explaining or pointing to a good link so I can better understand a scratch disk? I did a Google and it would seem to be a disk for temporary files for editing but I'm still not getting the benefit, usual size, how it helps... :eek:
     
  5. imacdaddy thread starter macrumors 6502a

    Joined:
    Feb 2, 2006
    #5
    Found this in wikipedia http://en.wikipedia.org/wiki/Scratch_space
     
  6. hayduke macrumors 65816

    hayduke

    Joined:
    Mar 8, 2005
    Location:
    is a state of mind.
    #6
    I think you'd be hard pressed to notice a difference between 3x750GB and 2x750GB RAID 0 in terms of disk I/O speed. In fact, unless you *know* you need RAID0 I would avoid it as you simply increase your risk of data loss, which can cost you a *lot* more in terms of time than anything you'll save with RAID0. If your RAID0 were *only* for scratch then that would be fine, but you've specified that it would have data as well.

    750GB is quite a bit of space (depending upon your project sizes I suppose). If you can keep OSX/Apps/Data on one drive and RAID0 the other two for scratch, that might be best. Also, if your projects are a source of income for you then invest in a back-up drive large enough to back-up everything (750GB?) and keep the 500GB as a spare back-up for extra important projects. So...

    1) 1 x 750GB for OSX/Apps/Data
    2) 2 x 750GB in RAID0 for Scratch
    3) 1 x 320GB for bootcamp to Windows

    It is kind of a waste of hard disk space, because you dedicate two large drives just for scratch space, but if you really need the speed this is probably the safest way to go.
     
  7. scottydawg macrumors 6502

    scottydawg

    Joined:
    Jan 22, 2008
    Location:
    Sacramento, CA
  8. Mr.PS macrumors 6502a

    Joined:
    Jan 8, 2008
    #8
    2 x 750's are my boot drive. All my files including OSX and all of my files. The stock 320gb HDD will probably be used for time machine, not sure.
     
  9. johny5 macrumors 6502a

    johny5

    Joined:
    Mar 31, 2007
    Location:
    UK
    #9
    Anyone know if it is possible to have software raid 5 using 4 x 1TB drives?
     
  10. bigbossbmb macrumors 68000

    bigbossbmb

    Joined:
    Jul 1, 2004
    Location:
    Pasadena/Hollywood
    #10
    OS X doesn't support software RAID5.

    to the OP, I wouldn't RAID the drives unless you actually run into a problem of not having enough disk I/O. Photo editing and video work (short of uncompressed SD/HD) will be more than fine on the Samsung drives.
     
  11. johny5 macrumors 6502a

    johny5

    Joined:
    Mar 31, 2007
    Location:
    UK
    #11
    ok thanks, I currently have 2 x 320gbs striped so when my F1 750 comes I will carbon copy back to one drive.
     
  12. ntux macrumors member

    Joined:
    Jan 29, 2008
    #12
    Also, don't forget that software RAID in Mac OS is partition-based, so that you can have both raid 0 and raid 1 on same disks depending on how you partition and raid them. But that sure makes weird partition schemes :D
     
  13. JesterJJZ macrumors 68020

    JesterJJZ

    Joined:
    Jul 21, 2004
    #13
    Anyone ever try a building a Raid 0 from one drive that was partitioned in half? :D It probably explodes or something.
     
  14. hayduke macrumors 65816

    hayduke

    Joined:
    Mar 8, 2005
    Location:
    is a state of mind.
    #14
    That doesn't really make any sense. Even if the software somehow arrived it would be pointless. All you would do is double your risk of data loss.
     
  15. kittiyut macrumors regular

    kittiyut

    Joined:
    Oct 28, 2007
    #15
    Yeah, it really doesn't make sense. However, if it can be done, it does NOT statistically double the chance of a "drive" failure since both partitions are on the same drive ;)
     
  16. imacdaddy thread starter macrumors 6502a

    Joined:
    Feb 2, 2006
    #16
    52 days and still waiting....

    Almost 1 quarter has gone by and still waiting... :mad: Bought mine from a local reseller but they told me I will definitely get it tomorrow. Sure.

    Anyway, I got a friend to order my 3 x 750 F1 last month while I wait and I just bought another one today totaling 4 x 750 F1. After 5 weeks of reading about HD and RAID setup, I think I'm set on the following.

    Disk 1 (1 x 750GB) - OSX & Apps (500GB) / Bootcamp Vista (250GB)
    Disk 2,3,4 (3 x 750GB in RAID 0) - Data/Scratch
    External HD for backup.

    I just can't wait to set this up already!!! Thanks for everyone's feedback!
     
  17. kittiyut macrumors regular

    kittiyut

    Joined:
    Oct 28, 2007
    #17
    1. You would've gotten your machine by now if you bought online
    2. I would reconsider doing RAID 5 for disk 2,3,4 instead of RAID 0 - you lose a little speed (in terms of disk I/O) and space, but you gain more in terms of redundancy (none in RAID 0) which I think far out weighs what you lose. If you are going to stick with RAID 0, have a good back up scheme - use both time machine and a dedicate HD to clone the array (perhaps you can use the original HD that came with the system)
     
  18. imacdaddy thread starter macrumors 6502a

    Joined:
    Feb 2, 2006
    #18
    Yes, I should have ordered it online but the reseller allowed me to make payments in 12 interest free installments. They messed up my order by shipping to others who had ordered after me...3 times!

    I was thinking of RAID 5 but I didn't go the hard RAID route. I definitely have a good backup plan on my external HD and also will make use of the spare 320GB.

    Cheers!
     

Share This Page