Thinking of trying RAID for the first time. Need advice.

Discussion in 'OT Technology' started by Guardfather, Jan 4, 2008.

  1. Guardfather

    Guardfather The Paradox

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    So I'm thinking of getting a couple of 150gb raptors to run in RAID 0. Eventually I might go to RAID 0+1.

    Now, is this something I can do with an Asus P5E LGA 775?
    http://www.newegg.com/Product/Product.aspx?Item=N82E16813131219

    Or would I need to get a separate RAID controller card? Also, I'm reading some things about needing a floppy drive for RAID drivers to be installed. I've also read that there's a way to do it with a CD too, though it's not as straightforward? I'll be installing XP-64 SP2, so I'm not sure if that revision has the necessary RAID drivers or not.
     
  2. P07r0457

    P07r0457 New Member

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    DO NOT DO THIS.

    If it's simply for redundancy, RAID1 is okay. If you want speed+redundancy, look at RAID3/5

    NEVER EVER EVER EVER EVER use FAID0 for a main drive. The *only* time I will use FAID0 is for a dedicated scratch-disk.
     
  3. thebox

    thebox New Member

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    you can use on-board raid and it will work fine for raid0.

    raid0 ftw. just make sure you know what will happen when it fails, and how likely it is that it will fail.
     
  4. etech

    etech New Member

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    "Need advice."

    Don't bother.
     
  5. deusexaethera

    deusexaethera OT Supporter

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    Seriously, why do people ever consider using RAID0 for anything important? "I'm going to try something for the first time, and even though it's potentially devastating if something goes wrong, I think I'll opt for the cheapest possible approach." I mean, ten seconds on Google will give you all the eye-opening you'll ever need.
     
  6. P07r0457

    P07r0457 New Member

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    because he's a fucking idiot. FAID0 is a bad idea, anyway. But to trust a shitty onboard controller is the icing on the cake.


    The funny part is that for the short time that it does function, it won't actually net any speed improvement, so it's like shooting yourself in the head to sleep with a supermodel and then the supermodel turns out to be a fat-ugly-hairy man.
     
  7. dorkultra

    dorkultra OT's resident crohns dude OT Supporter

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    just get a raptor drive or a scsi drive, that will give you the speed you want
     
  8. Harry Caray

    Harry Caray Fine purveyor of x.264, h.264 & TS HD-Video !!! HD

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    :ugh: WTF ???

    He's a user coming to ask a question... :ugh2: You must be a big hit with the ladies (on WoW that is):mamoru:
     
  9. thebox

    thebox New Member

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    oh noes i'll have to reload windows and a few programs if my raid fails :greddy:

    pretty devastating :hsugh:
     
  10. Guardfather

    Guardfather The Paradox

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    I would be keeping my important data on other drives. I just wanted to have my OS and programs load as fast as reasonably possible. It's not like it would be devastating. I'd just have to reconfigure, and reinstall my stuff. The important data would be on other drives. If my important data were going to be on those drives, I wouldn't have considered it.


    However I did choose to just get a single raptor for my OS/App drive. I'm guessing I'll be more than satisfied with the speed compared to this computer.
     
  11. Guardfather

    Guardfather The Paradox

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    So asking advice from people qualifies me as a "fucking idiot"? I think it's clear who the idiot is here. There's no good reason to get all upset and call someone an idiot over this shit. If I were advising other people to put their absolutely most critical important data into such a storage mechanism, then I could see you getting upset. But me asking what others think about the idea is nothing near idiocy.

    People like you don't seem to realize that you create the very problems you hate. Rather than providing sound, considerate advice, you jump to name-calling and insulting the person's intelligence. This is why so many people are afraid to try to learn something about computers, and go begging other people to do the most inane shit. While I may not be one to take such ridiculous criticism to heart, others do. Try doing some good and showing a little patience so people learn something helpful without becoming afraid to try learning in the future.
     
  12. deusexaethera

    deusexaethera OT Supporter

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    ...okay...

    If he set up a RAID0, put all his shit on it, crashed it, and then came here asking for help to restore his data, THEN he would be a fucking idiot. As it stands, he had the sense to ask first.

    - - -

    OP: I have 3 Raptors in a RAID3 (similar to RAID5 except all the backup data is on a single disk instead of evenly distributed), using a $25 NetCell RAID controller. It's degraded itself once in two years, and a quick disconnect/reconnect of the failed disk allowed the controller to rebuild the lost data and it was good to go in an hour. For newer drives, you'd want a newer RAID controller, but if you're going to go with Raptors, the NetCell cards will do just fine.

    - - -

    Oh, and Jolly...don't go on any more blind dates.
     
  13. Guardfather

    Guardfather The Paradox

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    Awesome. I hadn't really learned anything about RAID3 until this thread. That does sound like the best option overall. If I choose to implement RAID in the future, that will be my choice.
     
  14. deusexaethera

    deusexaethera OT Supporter

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    Well...RAID3 is the best option for applications that will do a lot more reading than writing, whereas RAID5 is better-balanced. Since all the parity data (the correct term) is stored on one disk in RAID3, reading the array is just like reading a RAID0 -- the parity disk doesn't have to be touched at all; on the other hand, that also means when you're writing data to the array, all of the parity data that gets recalculated has to get funneled onto a single disk instead of being split across all the disks.

    For some reason that I don't entirely understand, RAID3 is actually a pretty unusual option to have on a RAID controller -- I myself probably wouldn't be using it if the controller I bought wasn't pretty much the only one on the market (within a reasonable price range) that offers it.
     
  15. Harry Caray

    Harry Caray Fine purveyor of x.264, h.264 & TS HD-Video !!! HD

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    Actually, RAID-1 is the best for maximum write and ultimate read throughput as the read I/O's will pull off of multiple disks/parallel (aka, data is addressed independently) I/O's for sustained performance that are well above any other RAID or nested levels.

    EMC, NetApp, Pillar, HDS (hitachi data sys) and others choose to use R1 for specific LUNs on target partitions that will be used for DB's and other high IO, heavy hit apps...

    That is, a RAID 1 array of two drives can be reading in two different places at the same time

    On a side note, effects of RAID 3 is that it generally cannot service multiple requests simultaneously. This comes about because any single block of data will, by definition, be spread across all members of the set and will reside in the same location. So, any I/O operation requires activity on every disk.:ugh:
     
  16. deusexaethera

    deusexaethera OT Supporter

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    Saying that a single block of data will necessarily be spread across all disks in RAID3 assumes that the stripe width is narrower than a single block of data can fit in. Of couse, it's a pretty useless argument either way, since "block" and "stripe width" are variables and not actual numbers. So I'm gonna go ahead and say that you're full of shit, but only with regards to RAID3's that don't resemble the RAID3 you were imagining when you wrote that post.

    As far as any RAID's ability to service multiple requests simultaneously, that really comes down to the RAID controller, not the RAID configuration. A $1000 controller will be able to do the math for any RAID config to pull pieces of data blocks from multiple disks at once in order to satisty multiple queued requests at the same time, whereas a $20 RAID controller won't even have enough sophistication to read two different data blocks at once from a RAID1, like you were talking about above.
     
  17. Harry Caray

    Harry Caray Fine purveyor of x.264, h.264 & TS HD-Video !!! HD

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    Well, you can say whatever you want, the "standard" specification for R3, R4, R5, etc,etc is that all data (aka parity) is spread out across all the disks... PERIOD. You don't like this.. well tough shit. You want a single file, it HAS to be pulled off EVERY SINGLE DISK and the controller has to verify the integrity of the metadata off each drive as it comes off.

    You don't like that? well WHO FUCKING CARES.. that the way the real world works. That why only a 20disk EMC DMX system will have a GAZZILION GB of RAM and bazzillion PowerPC processors just to handle the I/O, caching, etc,etc..

    And to answer your question, yes, even the CHEAPEST of RAID controllers will do parallel RAID 1 reads. The High-P RocketRaid 133 ($39) that I used to put in all my clients machines does it in R1.. the RocketRaid 404/454 does it... etc,etc..

    And this coming from the guy that put ReiserFS on his boot /:rolleyes:
     
  18. deusexaethera

    deusexaethera OT Supporter

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    Ah, you were talking about parity checking when you said the controller had to read all of the disks when using RAID3. I misunderstood, I thought you meant all the disks had to be read just to get the data you wanted.

    To be fair, that isn't something special about RAID3 -- any RAID that stores parity data (i.e. not just a simple stripe or mirror) will have that stipulation, that all disks must be read to check the parity data. You said so yourself, but I wanted to spell it out more clearly because the way you said it was easy to miss.

    Well, I guess I now know the one saving grace of RAID1 (compared to higher RAID levels). Too bad it has to be so space-inefficient, though -- I just don't at all like the idea of losing half my disk space and not having any scalability to speak of, which is why I went with a higher-level RAID in the first place.
     

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