MacPro5,1 Best SW Raid config?

Discussion in 'Mac Pro' started by Gr1f, Feb 12, 2013.

  1. Gr1f macrumors member

    Joined:
    Oct 1, 2009
    #1
    Hi Folks,
    As I just ordered a Crucial M4 512GB I thought I might reconfigure my 2 HDs currently set to SW Raid0 that I was using as my boot drive.

    Can I (or should I) run SW Raid5? I can shove a couple of more HDs in there similar to the 2 already in it and Raid5 them all?

    Thanks for your help as always!
     
  2. deconstruct60 macrumors 604

    Joined:
    Mar 10, 2009
    #2
    As a file server or primarily as a single user workstation ?

    As a workstation pragmatically, No.

    Apple's solution RAID 0 , 1 , 10
    http://support.apple.com/kb/HT2742

    SoftRaid 0 , 1
    http://www.softraid.com/features.html

    As a file server defacto RAID 5 through ZFS. RaidZ is better than RAID 5. The CPU/Memory overhead is higher enough though that probably don't want to be running several resource intensive user applications at the same time though.

    http://getgreenbytes.com/solutions/zevo/

    or MacZFS.


    I don't think there is anything like Linux's mdadm on OS X. (so no RAID 5 or 6 ).
     
  3. Gr1f thread starter macrumors member

    Joined:
    Oct 1, 2009
    #3
    deconstruct60,
    Thanks. yes it's a workstation. Design apps like Adobe Suite and some Cinema 4d stuff and webs dev. So I should just leave my Raid 0 config!
     
  4. deconstruct60 macrumors 604

    Joined:
    Mar 10, 2009
    #4
    RAID 0 needs an automated, highly available back-up option, but yes that is one option.

    Drive Bay
    1 SSD
    2 media RAID-0 A
    3 media RAID-0 B
    4 ??
    external back-up TimeMachine/Chronosync/etc. Larger slower drive.

    Another would be RAID 10

    ODD Bay 2 SSD
    Drive Bay
    1. media RAID-10 A
    2. media RAID-10 B
    3. media RAID-10 A2
    4. media RAID-10 B2

    external back-up the same as above.

    Here can take same single drive failure as RAID-5 and keep going. Apple's Software RAID will do this. Back-up doesn't have to be as time critical (maybe once a day or so) so not as great a need for continuous snapshot migration.
     
  5. Gr1f thread starter macrumors member

    Joined:
    Oct 1, 2009
    #5
    Yea, I've a NAS for TM backups :)
    maybe Raid0 4 drives instead of 2..... hrmm.
     
  6. phrehdd macrumors 68040

    phrehdd

    Joined:
    Oct 25, 2008
    #6
    When you say SW RAID do you mean Apple's native ability or a third party software? If you mean the former there is no RAID 5 just 0,1, 01 and 10.

    I have booted up on striped drives with no issues. However, if an issue occurs on one drive, the entire stripe is lost.
    Scenarios I have tried successfully -

    3xdrives raided + 4th drive that was larger than the total volume created by the stripe and used it for a backup internally. If the RAID fails, I can use the back up immediately.

    Boot up on single SSD, stripe 2 regular drives for scratch space, 4th drive again for backup

    RAID 10 regular drives -works but no real value given there are other options that appear to work better. I consider 10 best left for network storage.

    I would suggest you consider boot up on your SSD along with your apps. Additional consideration for other drive(s) for scratch space, downloads etc.
    Asynchronous back up to 4th drive - as in full back up once, then manually or by setting do backups of deltas (differences). Simple software such as the CC cloner and Superduper should work very nicely. Btw a nice combo would be SSD boot up, two velociraptor drives striped for scratch and downloads etc. and then a 4th simple drive for back up.
     
  7. deconstruct60 macrumors 604

    Joined:
    Mar 10, 2009
    #7
    Striping 3 wide is suspect. Striping 4 wide is plain just dubious in this context. If really need "super fast" scratch then get another SSD.

    Or striping 2 for scratch and 2 for sources/finished product. What you need to do is move different groups of files (e.g., temporary versus permanent ) to different raid sets. It is misguided to just keep on cranking up the striping width to suck in more files like the Blob/Black-hole.

    Unless that is a fast, low latency network bouncing it outside will likely kill off the RAID-0 aspect of that array. May be useful if 10's of users are banging away at the same set of drives.

    RAID has no write hole and much lower software overhead than RAID 5.
     
  8. Gr1f thread starter macrumors member

    Joined:
    Oct 1, 2009
    #8
    OK, What i'm going to do is simply leave my 2xHD Raid0. I can live with that till I can get my hands on a realistically priced 1T+ SSD or two....

    I will do a clean install on the SSD and only transfer basic settings from the older boot drive.

    I will re-install apps on the SSD from scratch and leave documents, photos, music (3 largest directories) on the original Stripe.

    Thinking about it... It would be great to be able to have a 4HD array with redundancy and speed. Seeing as I have the space....
     

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