Restoring from RAID setup

Discussion in 'Mac Pro' started by RebootD, Aug 25, 2009.

  1. RebootD macrumors 6502a

    RebootD

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    NW Indiana
    #1
    In my Mac Pro I currently have the stock HD as my OS/Home drive, while the other two 1TB WD Black drives are RAID 0 partitioned into a 1.5 TB Data drive and 256GB Scratch.

    I have these and my OS/home drive backing up to time machine but when I eventually upgrade to 10.6 (and probably clean install) will I lose my RAID setup and have to re-create it byte-by-byte in order to restore from my Time Machine backup? Or would I have to do the 'upgrade' installation to get around this since I used Disc Utility to create my RAID setup?

    Any help much appreciated.
     
  2. UltraNEO* macrumors 601

    UltraNEO*

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    #2
    For a start no-one really knows what options Apple will include in SL but from previous experience there should be the usual "Install" or "Upgrade" options and something called "Archive and Install"... But I guess that depends which version you buy.

    I would only use Disk Utility only if i need to make modifacation to the disk structure/parition other wise I would of thought it's gonna be a stright forward install.

    When it comes to TM restores well... I guess depend on what you want to restore. If it's just the home directory then I don't see any issues.
     
  3. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #3
    As UltraNEO pointed out, the options should be the same, or extremely similar. At any rate, the GPT structure would remain intact, so when you do a clean install, it will show the array as a single volume (when you select installation volume). You would proceed the same way after you initially created the array. ;)

    BTW, why did you partition the array like that?

    I ask, as assuming the 1.5TB is first, and the balance after, it resides on the inner tracks, and simultaneous access would slow down both arrays (assuming you run into this often). Otherwise it's fine.
     
  4. UltraNEO* macrumors 601

    UltraNEO*

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    #4
    Personally for a RAID0 I wouldn't partition it at all! Using two partitions for storage and scratch always seems to slow it down... it's not like it's a RAID5/RAID5 setup where is multiple heads moving at different times.
     
  5. nanofrog macrumors G4

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    May 6, 2008
    #5
    Neither would I. It gives more capacity to keep the used space at 50% or less for best throughput.

    Assuming it's for video/graphics work, the simultaneous access issue is real (app + data on one array, scratch is the second). :( But I asked the question to make sure. ;)
     
  6. Macinposh macrumors 6502a

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    #6
    raidschmaid.

    well,i moved last week from tiger to leo and leo did not recognize my raid10 for installment at all.
    it recognizes the raid10 itself just fine after I put leo on to another drive (tiger=4drive raid10 in internal bays,leo=bay5 as boot disk), read and write,everything was ok.i could even boot from leo,write stuff on the tiger disk,restart to tiger and read it.

    but I couldnt update the tiger=raid10 to leo,nope.nada.nilch.
    go figure.


    if you want to play safe,back up for a external drive as well,just in case...uuhh..weird appleish issues will arise.
     
  7. UltraNEO* macrumors 601

    UltraNEO*

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    #7
    I don't expect the same thing to happen when it comes to Leopard to Snowy upgrade, it's more a architecture patch IMO; 32bit to 64bit code.
     
  8. nanofrog macrumors G4

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    May 6, 2008
    #8
    That sucks, but there's more of a difference between Tiger and Leopard IIRC. As SL is just Leopard optimized and a few new API's (Grand Central,...), it's far closer.

    But it's always good practice to backup just prior to any changes. ;)

    As you say, it's Apple afterall... :p
     
  9. Macinposh macrumors 6502a

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    #9
    well,honestly,me neither.

    but what I have learned,is to expect for the spanish inquisition...



    It.Just.Comes!
     
  10. RebootD thread starter macrumors 6502a

    RebootD

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    #10
    I actually followed a guide online when I got the new MP. I have all of my apps/home drive on the 640 that came with system. I then bought 2x 1TB drives and put my Data onto the 1st larger partition and made a secondary partition for when my render/cache/photoshop scratch.

    I ran tests like xbench and my RAID drives were 40% faster access compared to my boot drive. My workflow is open file from DATA and if I ever run out of ram my SCRATCH partition takes over.. but I don't think I put it near any real stress to have noticed a slow down. (?)

    But yeah if anyone has a better idea (just use one of the drives for data and one for scratch) let me know, always open for new ideas!
     
  11. nanofrog macrumors G4

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    #11
    Create the array as a single partition (scratch shares it).

    You should be seeing more than a 40% increase. More like 2x (of a single disk performance of the model used in the array). This would hold true for the Caviar Blacks vs. any of the Green or Blue models of the same capacity. AS the capacity increases, so does the performance. Seriously.

    As I was trying to explain earlier, using partitions to create multiple arrays on the same disks when there's simultaneous access, WILL slow you down. (Same drives, same controller, trying to serve 2 requests at the same time = bottleneck). Perhaps a little simplified, but hopefully, you get the idea. ;)

    Additional memory may be needed (I didn't see a physical memory capacity listed), as the concept of a scratch space was due to the past, where high costs of physical memory were prohibitive. Now, it's cheap enough that having adequate memory isn't an impass, and is much faster than any drive by a massive margin. ;)
     
  12. RebootD thread starter macrumors 6502a

    RebootD

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    #12
    Thanks for all the info and sorry it took so long for me to respond.

    I got 10.6 up and running from a clean install (and that fixed my Illustrator crashes and my MP sleeping issues thankfully) so I am going to revise my RAID 0 setup as one giant partition and see how that works for me. (and it kept my array intact while I erased and installed SL)

    I honestly never thought 2x partitions on the same array = bad. Then again this is my first attempt at it! :D
     
  13. nanofrog macrumors G4

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    #13
    :cool: Keep posting updates as you continue to make progress, if you don't mind. :)
     
  14. RebootD thread starter macrumors 6502a

    RebootD

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    #14
    Well good news I easily deleted the multiple partitions and created one giant DATA RAID 0 array with the two drives. I ran xbench and got the same overall score (246) but I can run it again if anyone really wants to the read through the details.

    So far it seems just as fast as before but I haven't done anything this weekend to stress using it for scratch and opening/saving at the same time.
     
  15. RebootD thread starter macrumors 6502a

    RebootD

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    #15
    Well I ran another xbench test so here were the results from the RAID array:

    Disk Test 166.07
    Sequential 204.98
    Uncached Write 348.52 213.98 MB/sec [4K blocks]
    Uncached Write 349.29 197.63 MB/sec [256K blocks]
    Uncached Read 87.83 25.71 MB/sec [4K blocks]
    Uncached Read 417.23 209.70 MB/sec [256K blocks]

    Random 139.58
    Uncached Write 59.43 6.29 MB/sec [4K blocks]
    Uncached Write 730.17 233.75 MB/sec [256K blocks]
    Uncached Read 166.09 1.18 MB/sec [4K blocks]
    Uncached Read 225.29 41.80 MB/sec [256K blocks]
     
  16. nanofrog macrumors G4

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    May 6, 2008
    #16
    Now experiment around with your work flow, and see how it feels. :)
     

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