Home folder on RAID 5, or Entire system on RAID 0+1?

Discussion in 'Mac Pro' started by benguild, Aug 12, 2009.

  1. benguild macrumors 6502a

    Joined:
    Jul 29, 2003
    #1
    Okay, I have two choices.

    1. Apple's Mac Pro RAID Controller, Four Drives, RAID 0+1
    One big disk, highest cost.

    2. Or, some other RAID Controller (?), Three matching drives, RAID 5.
    Then, 1 big drive for OS/Applications/Time Machine.


    I'd probably move my Home folder to the RAID Array and have just my data striping amongst those drives. Has anyone had a dilemma like this before? I like the idea of hardware separation of my Home folder from the OS.
     
  2. benguild thread starter macrumors 6502a

    Joined:
    Jul 29, 2003
    #2
    The other thing that I'm considering is installing four new drives (identical) and doing a Software RAID 10, then installing a carrier into the spare optical drive port and using one of the motherboard's SATA ports for the connection of a 5th drive for OS/Applications/Time Machine.

    I can't make up my mind. I haven't been happy with the performance of a software RAID 1, and I have an original launch 2006 Mac Pro.

    Help me. :(
     
  3. gugucom macrumors 68020

    gugucom

    Joined:
    May 21, 2009
    Location:
    Munich, Germany
    #3
    The question is why you feel you would need redundancy at all. It is usually only needed for servers where gaps in data backup during crashes would be lethal. If you are using reasonable backup practises you will not have a huge exposure by dropping redundancy.

    The money is better spend by installing faster dedicated boot and apps drives. Consider a 2x80 GB SSD boot RAID0 and a 2x1,5TB storage RAID0. Time machine external on a 2TB TC or internal in ODD bay 2 with a 2TB.

    I looked at RAID cards and concluded they give you nothing. You start getting effects from PCIe 4 lanes with SAS drives upwards. They cost close to 200$ and quickly go to 500$ for 8 lane. But those cards really only make sense if you have server exposure and then you want to be on serious enterprise class SAS drives as well. Software RAID0 is working excellent for most people I have known here on MacRumors.

    If your backup goes beyond 2TB you can look at a Highpoint RR2642. I will use this for additional 2 internal SATA SAS ports and 2 eSATA ports for adding external backup when I run out of internal or TC capacity.
     
  4. benguild thread starter macrumors 6502a

    Joined:
    Jul 29, 2003
    #4
    The OTHER thing that I considered was a Drobo ... but that seems like it'd be even slower and the single-point-of-failure would be a Firewire 800 port. Plus, then I'd have more clutter under my desk and another cord to plug into the UPS.

    So basically, I think no matter what a Software RAID 10 would be faster than a Drobo... but I'm just having a really tough time understanding what my best option is here. I like the idea of a Software RAID 10 with a 5th drive in the 2nd optical bay, but is that really faster than a Hardware RAID card from another vender? (it's obviously cheaper)
     
  5. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #5
    Apple's controller is JUNK. It's slow, expensive, only works in OS X, and still has issues with the battery.

    You'd be far better off with a 3rd party controller. The details will depend on the specifics, but they're capable of more array types than Apple's card, and certainly capable of 1+0. Details get into boot support, driver support, and port count & configuration.

    Take a look at Areca or Highpoint. The Areca's offer better features, particularly for boot support. Highpoint's can only boot a single OS (it can do either OS X or Windows/Linux, as it can only hold BIOS or EFI, not both).
     
  6. benguild thread starter macrumors 6502a

    Joined:
    Jul 29, 2003
    #6
    I mean basically I only have 500GB of data since I do primarily web-development, but if I had a hard-drive die out or start to corrupt, I would lose scripts I'd just written completely by hand or pages/illustrations I've designed in Photoshop.

    Since I'm not editing video or working with very-large files (although I do edit video occasionally, but not primarily), I'm presented with many more options here... but I just can't figure out what my route is.

    My plan is to start fresh with Snow Leopard, and I don't think Time Machine is enough. I mostly use Time Machine for reverting to previous versions of files if I want to literally "go back in time". Right now I have 3 hard-drives... two in a Software RAID 1 and the other for Time Machine.

    If Apple's card sucks, I won't buy it. However, I really can't decide what to do here because I'm not sure if Software RAID is slowing down my day-to-day routines enough that I should go back to a single-drive and risk it all.
     
  7. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #7
    It sounds like you'd be fine with OS X's software RAID functionality. It's not that much difference in performance (almost negligible) compared to a hardware RAID controller (not Fake RAID).

    If you're sticking to 3 drives, then the current setup is going to work. 2 drive RAID 1, and a backup drive.

    If you'd like a little more speed, and keep that degree of fault tolerance, get 5 disks, and use 4 in a RAID 10, and the 5th is the backup. Rather simple, and quite a bit less expensive than adding a RAID card to the mix.

    If you'd like to improve the reliability even more, you'd want to consider enterprise drives, rather than consumer models. They've better specifications, particularly the UBE (Unrecoverable Bit Error), as it's 1E15 vs. 1E14 for most consumer models. They also have some additional sensors that keep the drives in better shape (fly height adjustment for the heads), so the statistics for a head crash are lower.

    Up to you. ;)
     
  8. benguild thread starter macrumors 6502a

    Joined:
    Jul 29, 2003
    #8
    Okay, how is this for a plan:
    4 x 500GB hard-drives in a Software RAID-10, mounted in the factory bays.... (home folder only)
    1 x 750GB enterprise hard-drive mounted in the extra optical-drive bay -- partitioned as 100GB for Operating System & Applications, the remainder for Time Machine

    ... would that make sense? I don't know what drives to buy either, so I'm only halfway there if this is a decent plan. I already have an extra SATA cable for the 5th drive, but I'd need something to convert the bay to 3.5"
     
  9. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #9
    Not quite.

    This would be better:
    4x enterprise drives in RAID 10, contains the OS, applications, and data.
    1x consumer drive for backup (usable in this setting, as it's not accessed nearly as often)

    I'm partial to WD lately, and would recommend the RE3 models for enterprise. The Caviar Black would suffice for the backup drive, but even the Seagate 7200.12's would as well if you'd want a little more throughput, as the WD is 334GB per platter, and the Seagate is using 500GB per platter. Check the reviews on these however, and pay particular attention to the reliability, given the 7200.11 series. Newegg's customer reviews can help with this. (I've not checked out this line).
     
  10. benguild thread starter macrumors 6502a

    Joined:
    Jul 29, 2003
    #10
    I appreciate all of the help!
    Are you sure it wouldn't be faster to have the Applications/OS/Backup on a separate drive like that, or is it easier just to dogpile everything together, haha.
     
  11. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #11
    There's a reason to what I described:

    DO NOT place the primary and backup data on the same disks. EVER. A separate array can't protect you from an actual drive failure(s). So despite the array type used (fault tolerance), all data can be lost. Thus it's proper practice to keep backups on completely separate drives. ;)

    Hope this clears up any confusion. :)
     
  12. benguild thread starter macrumors 6502a

    Joined:
    Jul 29, 2003
    #12
    Got it.
    Do you think the performance increase will be noticeable from RAID 1 to RAID 10 for random read/writes?
     
  13. Macinposh macrumors 6502a

    Joined:
    Jun 7, 2006
    Location:
    Kreplakistan
    #13

    Ding ding! We have a winner.


    I have now been running software raid10 for about exactly 3 years today in my MP 1.1.
    Without a hitch (knocks wood).
    4 disk raid10 internally and 5th drive in the optical bay. CCC taking care of hourly backups of the system/present media on the main disk. I archive on external 1TB disks.
    It.Just.Works.

    On the apple raid cards,my associates have had a disasterous experiences.
    Of the 3 persons that I know,have had 4 disasters and several mishaps in total,resulting in 3 total data losses and a lot of work in general.
    So from my personal perspective,the hw cards have definately not been worth the money compared to the software raid...

    The data transfer rates have been good as well,now starting to work on hd video and it seems to be able to keep up with the transfer rates quite well.
    Let alone working with photos it has been more than enough.


    My .02 rubels.
     
  14. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #14
    Perhaps, but not as much as you might think (stripe size & usage can make a big difference here, but generally speaking). Though the type 10 uses 4 disks, the performance is still based off only 2 of them, as the other pair are just duplicates (mirror).
     
  15. benguild thread starter macrumors 6502a

    Joined:
    Jul 29, 2003
    #15
    Okay guys, thanks for all of your help.
    I've begun ordering 1 hard-drive every three days to try and get disks from different batches. We'll see.
     
  16. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #16
    Best to use different suppliers if possible. :) It changes the pricing a bit, but you've better odds you won't get drives out of the same batch. ;)
     

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