Would a RAID 0 setup be a bad idea in my situation?

Discussion in 'Mac Pro' started by Sharky II, Nov 3, 2011.

  1. Sharky II, Nov 3, 2011
    Last edited: Nov 3, 2011

    Sharky II macrumors 6502a

    Sharky II

    Joined:
    Jan 6, 2004
    Location:
    United Kingdom
    #1
    Hi guys

    I have a 2008 8 x 2.8Ghz Mac Pro that iI use in my studio. I'm going to buy a SSD soon, for my boot drive. I currently have these drives (not including my 2 externals):

    Bay 1: Samsung F3 1TB (System drive)
    Bay 2: Samsung F3 1TB (Main 'Audio' Drive)
    Bay 3: Samsung F1 750GB (TimeMachine Backup of the above two drives (they are not full))
    Bay 4: Stock Apple 500GB HD (This still has 10.5 System drive on it in case any old projects don't open)

    I haven't needed the Bay 4 drive in a long time, so will probably wipe that and use it as extra backup. I also have the two External drives i use as backups for some extra redundancy.

    Anyway to get to the point, i was hoping to get an SSD for the OS/apps, and Software RAID0 the 2 x 1GB Samsung F3's for audio data, for faster sample streaming and shorter project load times. Then i want to use the rest of the drives to back up frequetly, with time machine and CCC.

    However my situation is that i'm in a studio that unfortunately has occasional power cuts (main trip switch) - perhaps one to two a week. Currently I haven't lost any data other than what's lost from not saving whatever i'm working on before the cut occurs.

    If running a software RAID 0 setup of the two F3 drives, is there more likelihood of losing data under these circumstances (power cuts)? The Mac is on a surge protector, but i'm worried about using a software RAID 0 setup as i read that it was more prone to failure/corruption/data loss during power cuts/surges.

    Is this true?

    Thanks!

    Eddie

    P.S. - Yes, i'm working to resolve the power cuts in the first place, but it's proving to be a very tricky problem to fix!
     
  2. brentsg macrumors 68040

    Joined:
    Oct 15, 2008
    #2
    It's not a tricky thing to fix. You need to put your MP on a good UPS.
     
  3. Sharky II thread starter macrumors 6502a

    Sharky II

    Joined:
    Jan 6, 2004
    Location:
    United Kingdom
    #3
    UPS's, while great, are usually noisy (and expensive), and unfortunately i am only a small private 'one room' studio, i don't have a separate machine room.

    By tricky, i meant i've had electricians round and they're all scratching their heads and can't seem to find a reason for the trip switch tripping

    Thanks,

    Eddie
     
  4. peabo macrumors regular

    Joined:
    Feb 14, 2008
    #4
    Set up time machine with an external backup drive and you should be safe.
     
  5. Loa macrumors 65816

    Loa

    Joined:
    May 5, 2003
    Location:
    Québec
    #5
    Hello,

    My UPS (from APC) is dead silent unless in use. In your case you could buy a relatively cheap UPS just to protect against the trips. If those last too long, just safely shut down your mac. Seems the best alternative, as the benefits of a RAID0 will be great in your case.

    Loa
     
  6. Sharky II thread starter macrumors 6502a

    Sharky II

    Joined:
    Jan 6, 2004
    Location:
    United Kingdom
    #6
    Thanks guys. I had no idea they were so cheap. Thanks for pointing me in the direction of the APC ones. I've calculated how much wattage i'd need, and it's not much. One of the cheap £85 ones will give me 400watts for 4-5mins, which is plenty - the trip switch is in the same room so i only need it for 30 seconds. Even if there is a 'real' power cut - i'm happy to have enough time just to shut down.

    I see no fan at all on something like this: http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=BE700G-UK&total_watts=50

    So it should be totally silent.

    Which APC UPS do you have, Loa?

    Last time i checked UPS's were £500 and had big fans in them, i guess i didn't check for more 'consumer' stuff. If this £85 is sufficient for me, i'll get that before an SSD.

    So, am i right in assuming that software RAID 0 is indeed more volatile in a power cut vs a single HD?

    Thanks again
     
  7. Tomorrow macrumors 604

    Tomorrow

    Joined:
    Mar 2, 2008
    Location:
    Always a day away
    #7
    That's a new one on me. I have a 1500 VA UPS at my desk side that doesn't make any noise at all (unless the power goes out, in which case it starts beeping like someone's breaking in).

    RAID 0 stripes data, so if you lose one disk, you lose everything. Essentially, you're doubling your chances of a failure.
     
  8. Sharky II thread starter macrumors 6502a

    Sharky II

    Joined:
    Jan 6, 2004
    Location:
    United Kingdom
    #8
    Thanks. I wasn't aware of that before i posted this :eek:

    Thanks again. I was aware of that. What i was asking is - because the RAID is done via software, if the data is more prone to corruption when power is lost, vs a single drive, which doesn't seem to have any issues.

    Eddie
     
  9. khollister macrumors 6502a

    khollister

    Joined:
    Feb 1, 2003
    Location:
    Orlando, FL
    #9
    Not sure of the type of music you are doing and the relative mix between audio recording and MIDI sample playback, but I would suggest something like this:

    SSD for OS/apps/effects/VI's

    RAID 0 stripe for sample libraries

    Single HDD for audio track recording

    TM

    The reasoning is that the sample playback is the high performance application, and since it is read-only, the lower reliability of RAID 0 is of little consequence if you have a current backup

    A separate audio drive keeps the overall performance up, but improves the reliability on data that is being written
     
  10. Sharky II thread starter macrumors 6502a

    Sharky II

    Joined:
    Jan 6, 2004
    Location:
    United Kingdom
    #10
    Hi, thanks for your feedback!

    I don't really have too much sample playback stuff. It's only a few large sample libraries - about 20gb - this can live on the SSD as i'm going to get at least a 160gb, and won't even use near half that with my OS/apps/plugs.

    The stuff i put on the SSD will be the large 3rd party Kontakt libraries that need faster load time, but also will help the DFD stuff. The standard Kontakt stuff/everything doesn't take much time at all to load anyway.

    I'm mainly looking to speed up projects loading all the projects and audio files (as i'll have 2 identical drives 'free'), the killer sample library stuff will be on the spare space on the SSD.

    But i agree that your way would mean that the crucial data would be on a single drive, meaning less chance of... bad things.

    Thanks!
     
  11. Tomorrow macrumors 604

    Tomorrow

    Joined:
    Mar 2, 2008
    Location:
    Always a day away
    #11
    I don't think it matters whether it's a hardware or a software RAID (except for performance) - it's a matter of when a drive fails. If everything is on one disk, and you lose that disk, you lose all your data. If everything is on a RAID 0, and you lose one disk, you lose all your data - except with the RAID, there are twice as many disks you could possibly lose, which increases your chances of a failure.

    I don't have any numbers in front of me, but it was always my belief that a hardware RAID vastly outperformed a software RAID. And since the only benefit of RAID 0 is speed, I'm not sure whether the benefit is worth the risk - but that's just one user's opinion. :)
     
  12. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #12
    This isn't usually the case, and certainly not with a Line Interactive type (runs off of the wall when there's sufficient AC power, and only switches to battery when the AC voltage drops below operational threshold). Once they've switched to battery, you can hear, them, but they're not "screaming banshee's" either. You'll be able to live with it (might be an issue if it engages, and you've an active mic in the same room as the UPS when it switches to battery).

    There's also different inverters with UPS's, and you'll want to get a Pure Sine wave model, as it's much closer to an AC sine wave than a stepped inverter. The reason for this, is because the PSU in the MP can be damaged when it switches over to the inverter + battery (any Active Power Factor Control, aka Active PFC based PSU suffers this issue, which the 80%+ efficiency rated units are).

    So it's best to get the right inverter type to begin with, as PSU's aren't exactly cheap for MP's (usually see them for ~ $300 USD).

    Avoid this like the proverbial plague.

    You'd be better off with this or this. Prices will be under $300 per, and closer to $200 for the Cyberpower version (it's actually a PWM based inverter, but it's designed to work with A PFC type PSU's without causing damage). Others here have used it, and I've recently bought a smaller one I'm happy with (put the HDTV and Satellite DVR on it).

    For a software RAID implementation, No.

    If nothing's being written, nothing goes wrong. If something is being written, you end up with an incomplete write (corrupt file), and have to do it over. Where this can be a real issue, is if it's writing a system file (part of the OS for example). But it's the same for either a single disk or RAID configuration. Using a UPS will reduce this issue, and is a good reason to run one, RAID or not.

    Where a stripe set does come into issue vs. single disk, is the risk of data loss is n * that of a single disk (n = member count), which you seem to be aware of. But this means additional time you'll have to put in to fix a problem (replace disk/s, then restore data) that you truly need to be able to put forth when needed (matter of when, not if). It also makes your backup solution that much more important (not just hardware solution/disks, but the scheduling you're using).

    Hope all of this helps. :)
     

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