Thread: RAID question?

  1. #1
    and the hat of sweating
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    RAID question?

    Hi,
    I just wanted to see if anybody here knows a lot about RAID and can answer this.
    I currently have 3 Seagate Barracuda 500GB SATA (model ST3500320AS) drives, and which are configured in RAID 5 (and RAID 0 which I plan to move to 5 soon), but I was wondering if the Seagate Barracuda ES (model ST3500630NS) would be a better choice to use for drives in a RAID 5 configuration? The Enterprise drives only have 16MB cache instead of the 32MB that mine have, but it says they're designed for "Dynamic, capacity-intensive RAID systems".
    Since they have less cache, I would guess they'd be a little slower than mine (unless there's something about them that makes them work better in RAID)?
    "I am probably the laziest programmer on the planet, a fact with which anyone who has ever seen my code will agree." - esbo, 11/15/2008

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    and the hat of int overfl Salem's Avatar
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    Read performance improves on RAID systems because (if the controller is doing it's job poperly) it will interleave all the reads across all the disks which contain the data.
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    Malum in se abachler's Avatar
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    The 16MB caches may be faster than the 32MB cache memory.

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    OK, but I think I also read something once about some kind of timeout setting on hard drives where it gives some kind of timeout error if it can't read/write your data in a certain amount of time, and if that happens the drive can get dropped out of the RAID array? Does anyone know what that's called? Would that ever help with todays hard drives?
    "I am probably the laziest programmer on the planet, a fact with which anyone who has ever seen my code will agree." - esbo, 11/15/2008

    "the internet is a scary place to be thats why i dont use it much." - billet, 03/17/2010

  5. #5
    and the hat of sweating
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    Nevermind, I found it: Time-Limited Error Recovery
    "I am probably the laziest programmer on the planet, a fact with which anyone who has ever seen my code will agree." - esbo, 11/15/2008

    "the internet is a scary place to be thats why i dont use it much." - billet, 03/17/2010

  6. #6
    Malum in se abachler's Avatar
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    By the time this becomes an issue, the drive is old enough that you need to replace it anyway. In any case you need to have a human make the judgement call as to whether to use teh drive or not. If you scan the disk and find that it is otherwise useable, all you have to do is reinsert it into the array.

  7. #7
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    Currently my system seems to be playing a game of Now you boot me, Now you don't. I'm wondering if it's one of my drives that are dying or if one of the drives is getting dropped out of the RAID array (which in my case is extremely bad since Windows is installed on RAID 0, so if any drive gets dropped, the whole RAID 0 array is useless). It was working fine for almost the first year and just started this nonsense last week, so I'm leaning towards the drive dying explaination.
    "I am probably the laziest programmer on the planet, a fact with which anyone who has ever seen my code will agree." - esbo, 11/15/2008

    "the internet is a scary place to be thats why i dont use it much." - billet, 03/17/2010

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