Which method is better to build RAID0 boot system

Discussion in 'Mac Pro' started by HyperX13, Nov 11, 2009.

  1. HyperX13 macrumors 6502

    Joined:
    Sep 3, 2009
    #1
    I have a Mac Pro 2008. I just got my second Crucial 256 gig SSD. Wanna make it a Raid 0 with my first one. Here are my thoughts.

    Process 1:

    1. Use disk utility to restore image of original Crucial 256 SSD to external USB drive
    2. Boot up with SL DVD
    3. Build Raid 0 using two drives. (do I need to 0 out?)
    4. Restore image to Raid 0
    5. Boot

    Process 2:

    1. Boot off DVD
    2. Create Raid0
    3. Use SL to restore backup from time Machine to Raid 0
    4. Boot


    Should both ways work? Which one is better?
     
  2. gugucom macrumors 68020

    gugucom

    Joined:
    May 21, 2009
    Location:
    Munich, Germany
    #2
    Both ways should work IMO. It depends a bit of the connection speed of your time machine, but if it is on the same external drive the second way may be a bit faster. Nevertheless I would always use way 1. The redundancy is higher and you have more options if you screw something up.
     
  3. kasbahlover macrumors newbie

    Joined:
    Dec 27, 2009
    Location:
    NY
    #3
    did it work?

    Would really like to know? thanks
     
  4. HyperX13 thread starter macrumors 6502

    Joined:
    Sep 3, 2009
    #4
    Yup both worked. I used option 1 and everything worked. I accidentally broke the raid a day later (my fault) so for the heck of it I used option 2 since time machine was most recent backup. My mac pro has 512 gigs of ssd and it flies!!!
     
  5. kellen macrumors 68020

    kellen

    Joined:
    Aug 11, 2006
    Location:
    Seattle, WA
    #5
    Nice HD's.

    I know you already did this, but when I did I chose option 1 and had number 2 as a backup.

    I am envious of your SSDs. How much do they run?
     
  6. HyperX13 thread starter macrumors 6502

    Joined:
    Sep 3, 2009
    #6
    I bought the first ssd for 440 dollars. It was through PC connection. Still had the original digital receipt. My 256 gigs was filling up fast, so I decided to do raid 0, I clicked on the part number (to buy another one) and now the m225 crucial was 789. I was like, WTF?? So I shopped around and found it for 550 on ebay. I know its a lot (considering I just got a 2 TB drive with 64 megs of cache for 229), but I really love the performance of SSD drive.
     
  7. superock macrumors newbie

    Joined:
    Jul 17, 2002
    #7
    Make sure you back up your Raid 0 frequently.
    I just had my Intel G1 SSD Raid 0 fail on me- and my backup was a month old. Sucked! One of the drives went kaput.
    The only good thing was that the drive got replaced by Intel and they sent me a G2 drive.
    I'm not going to raid them together this time as from my experience Apple's Software Raid SUCKS!
    This was the second time in a year- the first was with 2 regular HD's.
    Never again.... The single SSD is fast enough, I just miss the extra space.
     
  8. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #8
    Any reason you can't split the large files to a mechanical drive?

    That would put the random access needs on the SSD, and the sequential access on the mechanical, which provides inexpensive capacity, and is likely fast enough (mechanical can hit ~100MB/s+ avg. sequential reads now).
     
  9. HyperX13 thread starter macrumors 6502

    Joined:
    Sep 3, 2009
    #9
    Thanks for heads up but now I passed 256 gigs and I have to have raid 0. I am hoping crucial is reliable. Running time machine and super duper in case ;)
     
  10. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #10
    Well that's disheartening to hear. Sorry to hear about your loss. :(

    I was planning on building the same exact setup once I got a new Mac Pro. Is there any study out there that shows the failure rate of Apple's software RAID is higher than using a hardware RAID card? I'd really like to know this...
     
  11. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #11
    Hard to say, as some have had no problems, yet others total disasters. 10.6.2 has caused issues for some, and may be part of the cause, but there doesn't seem to be enough information to do much more than speculate as to whether or not it's actually damaging drives, or just caused instability for those that have had problems.
     
  12. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #12
    Hmm, so considering money isn't an object really, what would you personally go for? Or rather, should I ask, how is your RAID set up currently, if you do have one setup, and if you don't mind me asking :p
     
  13. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #13
    No SSD's, but 2x RAID sets:
    1 = ARC-1231ML + 8x WD RE3s in a RAID 5 config. It's been partitioned for an OS installation (Windows). The remaining space serves as a backup for the second card.

    2 = ARC-1680ix12 + 4x Fujitsu 15k rpm SAS drives for data (also RAID 5).

    4x Caviar Blacks serve as additional backup, clone space, and Linux. 1x Velociraptor for OS X.

    I may go with SSD for an OS disk in the future, but I'll wait until it's more mature (i.e. includes OS optimization). For RAID, I want to make sure it's reliable enough, and cheap enough for my capacity needs.
     
  14. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #14
    Nice, thanks for your input. :) I'll have to admit that some of that was over my head though. I'm still new to RAID so some of these brands and models are still new to me. I'm assuming the Arc in both your RAID setups are the hardware cards that you are using?

    I've been stalking any sort of RAID threads when I can. I really would like to minimize any complications myself.
     
  15. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #15
    Yes. Areca is the manufacturer of both.

    Quite understandable. Unfortunately, RAID tends to get complicated quickly, as it has to be taylored to each specific situation.

    You have to determine things like:
    • capacity requirement
    • throughputs (data speed needed for the intended use)
    • RAID level desired (0/1/10/5/6...)
    • environment (OS/s used and whether or not it will be booted from)
    • budget

    Once the usage is understood, then you can figure out if a hardware controller is needed (and associated features), drive count,...
     
  16. superock macrumors newbie

    Joined:
    Jul 17, 2002
    #16
    Well that's disheartening to hear. Sorry to hear about your loss. I was planning on

    I don't know of any study- but everything i've been reading lately confirms my experience...just backup regularly and I guess it doesn't matter- other than the down time LOL
    Nano I do have plenty of other HD space, I just liked to have a few gig's extra space on my startup drive for temporary downloads, and other **** before it's moved or deleted. My OSX install with apps, home folder, utilities, etc is about 75 GB's. I guess i'll deal with it.
     
  17. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #17
    Given the temporary nature of downloads, why not store them on HDD directly (mechanical), to avoid wear on the SSD (not to mention capacity, if it's that tight)?

    Given it's so close, you're too close to the limit, even with Intel's provision of 10% unused space for wear leveling (not available to the user). 20% is better IMO, so you'd want to keep the max at 72GB on an 80GB Intel drive.
     
  18. Icaras macrumors 603

    Icaras

    Joined:
    Mar 18, 2008
    Location:
    California, United States
    #18
    Wait, did you you mean to say leave at least 64GB free?
     
  19. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #19
    No.

    Assuming you've an 80GB Intel SSD, deduct another 10% <20% total> (8GB) from the available capacity, which leaves 72GB usable (16GB remains for wear leveling, which includes the 8GB <10%>that's unaccessible to the user by Intel for wear leveling purposes).
     
  20. fiatlux macrumors regular

    Joined:
    Dec 5, 2007
    #20
    I use a Gen2 80GB X25-M for boot drive, and that's plenty in my case. I only use about 30GB for MacOSX and apps (and I have [too] many apps installed).

    My home folder (including temporary downloads, settings...) is on a RAID0 stripe of mechanical discs. An identical RAID0 setup is used for Time Machine.

    Moving one's home folder to a separate partition/disk helps keeping the boot drive to the bare minimum.

    There might be some side effects, such as not being able to log in if the RAID stripe is not available. Which is why it is a good idea to create a special user (with administrator rights) for maintenance activities, with its home folder on the boot drive.
     

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