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Hard Drive Choice Concern WDRE2 Drive RRS feed

  • Question

  •  

    Hi

     

    I have 1 WD 500GB RE2 drive installed in the server, and have recently read that these drives are not really suited for WHS due to their Raid Specs and the way WHS treats drives.  Would i be best removing this drive and replaceing it? what issues could arrise from this drive?

     

    If i do have to pull the drive it would mean selling as i have no other system to install it in that does n ot treat as single drive.

     

    Thank You

     

    Rick (RB)

    Sunday, January 6, 2008 2:38 PM

All replies

  • The only reason I would take this out of your machine is to give it to me

    The drives are said to be some of the best WD have every produced and are designed for use in RAID units.  This means three things:

    1) They are desgined to be very very reliable

    2) They are low power units - so saving running costs

    3) Low noise / vibration - so being quiet

    Basically do not worry about the RAID class - the drive itself is not RAID and should not give you any issues beyond the normal drive fail risks with WHS.

    WHS is not designed for RAID configurations - it handles protection by itself when you use two or more drives and have folder duplication on.

    If you can afford it - buy another on of these and turn folder duplication on.

    Andrew

    Sunday, January 6, 2008 3:03 PM
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    Andrew,

    This is the only WD RE2 drive in the server the other 500GB is a err.. normal WD drive  Aling with a Seagate 160GB drive that came with the Proliant server i bought.

     

    There is a white paper somewhere which states the RE2 drives are not disigned for sinlge drive operation which is basically how WHS treats the drives as single ones.

     

    Dont think i will be giving the drive away any time soon  - nice try

    Most of the data on the server is already duplicated, so no worries there.

     

    I am just trying to find out if this drive will be ok to be left to do its thing in my WHS or not.  Must note that i have not had any issues so far.

     

     

    Sunday, January 6, 2008 3:09 PM
  • I've just been on the WD site again and cannot see anything that suggests you MUST use this in a RAID controller.

    The only two concerns I would have are:

    That they have limited the recovery the drive itself does:

    RAID-specific, time-limited error recovery (TLER) - A feature pioneered by WD, significantly reduces drive fallout caused by the extended hard drive error-recovery processes common to desktop drives.

    This may leave you more vunerable to failures as the controller in a single drive mode will rely on the drive to do the recovery rather than handling itself (on the RAID card).

    It also only has 16Mb of buffer
    This is low for single drives but better than a kick in the teeth.

    As I said above - I would be happy to use it in mine in place of my current WD500 drive.

    Andrew

    Sunday, January 6, 2008 3:48 PM
  • Andrew, Western Digital recommends against the use of their RE drives (which all have TLER) in non-RAID (and more specifically, non-enterprise RAID) environments. Here's the quote from their TLER information sheet:

    "It is important to relaize that TLER-capable hard drives should not be used in non-RAID environments."

    The information sheet explains how TLER works, and makes it pretty clear that it's only suitable for use with a RAID card that's capable of dealing with having an error reported from the drive without degrading the array. This excludes most "motherboard RAID" as they're basically just low-level software RAID and treat a drive error the same as a time-out.
    Sunday, January 6, 2008 7:55 PM
    Moderator
  • Thanks for that Ken - I did not think to check the system only the drive links.

    Remember the days when the only choice you had was 10Mb or 20Mb hard disks

    Andrew
    Monday, January 7, 2008 6:51 PM
  • I remember "disk packs". I used IBM 3330 packs in college...
    Monday, January 7, 2008 8:06 PM
    Moderator
  • Posh or what?

    I'm an old DEC pdp8e man myself - switches to load the bootstrap, bootstrap to load the PAPER tape reader in the terminal, paper tape to load the optical reader and all this to load the OS to boot from disk.

    As for the disk - wrapped in concrete to stop it shaking.

    Had to manually boot the thing over 20 times one day why trying to solve a power problem.

    Please forgive the hijack - its two glasses of good wine, a great open fire and wonderfull music in the hotel tonight
    Wednesday, January 9, 2008 9:22 PM
  • Andrew, dont mind the hijack no problem.

     

    I think what Ken has said has confirmed my fear,  i will have to replace this drive and sell it on.  would rarther not have to do this at the moment due to funds, but to be honest best the cost rarther than it causing issues in the server.

     

    I will read the white paper from western digital , just because i am interested to find out what affect it would have if the drive did fail.

     

    Thank you for your replies.

     

     

    Wednesday, January 9, 2008 10:54 PM
  • RB, the issue isn't that the drive will fail in your server, the issue is that the drive is designed to operate in a particular environment, and is tuned for that environment. The white paper I linked will tell you all of this in more detail, but the issue with desktop drives in RAID arrays is that they do a lot of error recovery on the drive, at the time you read the data. That can take a while, and the result is that the RAID array detects the drive as going off-line, so it drops it out of the array and degrades. Then the drive eventually comes back up and the RAID controller has to rebuild it, which hammers disk performance for hours (or days with a large enough array).

    TLER lets the drive return an error within a few seconds, so a RAID controller can move on and do it's own error recovery. Then when time permits, the controller and drive may do the drive's error recovery process. But in a desktop environment, returning an error within a few seconds is just like your drive returning any other read error. You lose data.
    Thursday, January 10, 2008 12:53 AM
    Moderator
  • Thank you for you input guys.

     

    I have decided to purchase another drive to replace the WDRE2 drive ... then sell the RE2 drive.

    Now have to decide what drive to use to replace it.

     

    Thanks Again.

     

    RB

    Thursday, January 10, 2008 9:44 PM