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Harddrive for WHS: Desktop or Enterprise model? RRS feed

  • Question

  • Shure there are several differences between the listed models.

    the "Enterprise" aka 24/7 ist certified for 24/7 duty and that is what WHS is supposed to be. An "allways on" system.

     

    The "Enterprise model" aka RAID Edition or 24/4 Edition will get hotter - does it need active cooling? ( I would like to know that for the HP SmartServer)

     

    The Enterprise model has a technical difference. Because I do not use RAID as a normal WHS-configuration, let me quote WD:

    Q:What is time-limited error recovery and why do I need it? 
    A: Desktop drives are designed to protect and recover data, at times pausing for as much as a few minutes to make sure that data is recovered. Inside a RAID system, where the RAID controller handles error recovery, the drive needn't pause for extended periods to recover data. In fact, heroic error recovery attempts can cause a RAID system to drop a drive out of the array. WD RE2 is engineered to prevent hard drive error recovery fallout by limiting the drive's error recovery time. With error recovery factory set to seven seconds, the drive has time to attempt a recovery, allow the RAID controller to log the error, and still stay online. 

     

    So what kind if harddrive is recommended for WHS in an 24/7 enviroment? We are talking about a system to secure data, so quality and technical harddrive data should be priority one to fit the needs of a backup system.

    Friday, September 7, 2007 4:57 AM

Answers

  • I would recommend against a drive with time limited error recovery, or equivalents from other manufacturers, in a WHS system. TLER is intended only for drives that are used in RAID arrays, not individual drives connected to a HBA.

    Modern disk drives have the ability to detect and correct a wide range of errors on their own, without ever involving other hardware or software in the system. The problem with consumer drives in RAID arrays is that this detection/correction can take a while, depending on what exactly is being done. For a single consumer drive, that means that the drive is unresponsive for a short time, which isn't (usually) a disaster. For a RAID array, having a drive go silent can result in an alert for a failing array, and a rebuild.

    TLER limits the time a drive spends trying to deal with errors. Instead, it will report a soft (I think; can't find the right tech doc on the WD site at the moment) error and keep going. For a RAID array, this is preferable. The array controller presumably has the ability to deal with the error, so it keeps the array online and operational.

    In WHS, TLER will result in the drive delivering that error back to the operating system, which will result in a read error on the client when attempting to access that file.

    For more information, see the fact sheet on the WD site. Note particularly the warning near the end that TLER capable drives should not be used in nonRAID environments.
    Saturday, September 8, 2007 12:58 PM
    Moderator

All replies

  • Hi,

    Since WHS not going with raid, and as knowing "NCQ" slow down the HDD, and WHS will be good for sharing and a like, I will really goes with desktop ver HDD, since it cheaper.

    Unless if you are after the better warranty, then the "Enterprise" will be good value.

    I nowday, only buy
    "Enterprise" ver of the HDD.

    My best.

    Friday, September 7, 2007 6:37 PM
  •  photoexposer wrote:

     

    So what kind if harddrive is recommended for WHS in an 24/7 enviroment? We are talking about a system to secure data, so quality and technical harddrive data should be priority one to fit the needs of a backup system.

     

    I "lightly" researched this a while back, when trying decide on the type of system that I would build.  I'll reference two of my sources that allowed me to come to the conclusion that "consumer-grade" hard drives would be ok for whs:

     

    1) http://arstechnica.com/news.ars/post/20070225-8917.html : shows how google uses over 100,000 "consumer-grade" hard drives in a 24/7 operation.  

     

    2)   http://www.usenix.org/events/fast07/tech/schroeder/schroeder_html/index.html : "we observe little difference in replacement rates between SCSI, FC and SATA drives, potentially an indication that disk-independent factors, such as operating conditions, affect replacement rates more than component specific factors."

     

    3) In addition, if you research some of the threads here, an overall consensus (if it can be called that) in one thread was that a drive spinning at 10,000 rpm will not provide a large leap in performance over a drive that spins at 7200 rpm due to the other bottlenecks in the (typical) system and the way whs is used.  To be honest, I’ve not given much thought to the matter, other than going out and killing one bottle-neck, and upgrading to a gigabit switch.  Doubt if I'd see much improvement using 10,000 or 15,000 rpm drives due to the way my systems are setup... or maybe anything that I could see or use.... 

     

    Of course, some "hard drive" expert might show 1,000 good reasons why you should pick a "industry-grade" HD over a "consumer-grade" HD.  I'm not an expert in this matter... only sharing what I found, and the conclusions that I came up with....

     

     

    Friday, September 7, 2007 8:09 PM
  • There are many angles you could answer this question with.

    First, Windows Home Server does NOT handle drives like RAID.  It will not "drop" a drive.  It will inform you there is something wrong with it but when it's running correctly, it will remain green. 

     

    I'd recommend a fast primary drive.  It is used more intensely than any other drive during file copies and while Drive Extender is working.

     

    The rest of the pool, I would just avoid using too slow of a drive while looking for drives that are reliable.

     

    Keep in mind that some drives consume more power and this is usually because they run at a faster RPM. 

     

    If you have duplication enabled, the needs for a reliable drive versus speed and size are greatly reduced.

    Saturday, September 8, 2007 12:01 AM
    Moderator
  • I would recommend against a drive with time limited error recovery, or equivalents from other manufacturers, in a WHS system. TLER is intended only for drives that are used in RAID arrays, not individual drives connected to a HBA.

    Modern disk drives have the ability to detect and correct a wide range of errors on their own, without ever involving other hardware or software in the system. The problem with consumer drives in RAID arrays is that this detection/correction can take a while, depending on what exactly is being done. For a single consumer drive, that means that the drive is unresponsive for a short time, which isn't (usually) a disaster. For a RAID array, having a drive go silent can result in an alert for a failing array, and a rebuild.

    TLER limits the time a drive spends trying to deal with errors. Instead, it will report a soft (I think; can't find the right tech doc on the WD site at the moment) error and keep going. For a RAID array, this is preferable. The array controller presumably has the ability to deal with the error, so it keeps the array online and operational.

    In WHS, TLER will result in the drive delivering that error back to the operating system, which will result in a read error on the client when attempting to access that file.

    For more information, see the fact sheet on the WD site. Note particularly the warning near the end that TLER capable drives should not be used in nonRAID environments.
    Saturday, September 8, 2007 12:58 PM
    Moderator
  • So everybody buying the RAID Editions or 24/7 Editions because of longer guarantee will come to problems in some time while installing these drives.

    Saturday, September 8, 2007 2:51 PM
  • Hi,

    Go with the 24/7 editions if you will not use the RAID ver.

    My best.
    Saturday, September 8, 2007 3:41 PM
  • As for which drives to use, I would just stay away from RAID designated drives, and I would read the specs on any other "Enterprise" or "24/7" drive very carefully. Personally, I buy OEM consumer grade drives. (I buy the OEM drives because they cost less than the retail packages and have a longer warranty.) The sweet spot in terms of dollars per GB is currently 500 GB, by the way; Newegg has them for as little as 99.99 plus S&H, though you can likely find them cheaper. I have had drives fail, but it's rare.

    And remember that every drive fails, and every drive experiences occasional soft errors. A drive that's designated for RAID use by the manufacturer presumably includes some sort of TLER, so it will tend to start reporting errors sooner, and more frequently, because the drive is passing errors back up to the HBA faster. This is likely to result in problems sooner rather than later.

    Saturday, September 8, 2007 8:05 PM
    Moderator
  •  Ken Warren wrote:
    As for which drives to use, I would just stay away from RAID designated drives, and I would read the specs on any other "Enterprise" or "24/7" drive very carefully. Personally, I buy OEM consumer grade drives. (I buy the OEM drives because they cost less than the retail packages and have a longer warranty.) The sweet spot in terms of dollars per GB is currently 500 GB, by the way; Newegg has them for as little as 99.99 plus S&H, though you can likely find them cheaper. I have had drives fail, but it's rare.

    And remember that every drive fails, and every drive experiences occasional soft errors. A drive that's designated for RAID use by the manufacturer presumably includes some sort of TLER, so it will tend to start reporting errors sooner, and more frequently, because the drive is passing errors back up to the HBA faster. This is likely to result in problems sooner rather than later.



    Hi,

    1 - Good point there, Ken.
    2 - Well said indeed to explain the issue, yes, RAID drives for RAID.

    My best.


    Saturday, September 8, 2007 8:17 PM
  • I currently buy seagate ES OEM drives from newegg. They only cost about $5 - $30 (depends on capacity) more than the consumer grade drives.
    Sunday, September 9, 2007 6:47 AM
  • I would also add to stay away from 2.5" laptop hard drives.  I'm talking about the traditional 2.5" pata ide drives, not SAS.  Some of those drives are designed such that they need to power down every once in awhile (I seem to recall 20 minutes in an hour) in order to maintain calibration.  My employer used them in a 24/7 network gear situation and started having HD failures in the field within a year.  After much investigation, it was discovered that the drives loose calibration due to thermal issues and just letting them power down and cool off will recover them (usually).  We never saw the problem because our development labs have a 67 deg. F ambient (or at least we try<G>), so they got enough cooling due to the low ambient.

     

    Bottom line, Not appropriate for 24/7 use.

     

    SC

    Tuesday, September 11, 2007 4:21 AM
  • Am I the only one who is using his old computer for a WHS??  I have an old P4 3.06GB with 6 120GB hard drives.  I figure this would be kind of an over kill for WHS.
    Tuesday, September 11, 2007 4:31 AM
  • I think a lot of people are finding that when you start looking at buying bigger drives, they want SATA which their old hardware may not support. And then they look at the 200watts their old P4 draws and see the 60watts of the new processors and then everything kind of snowballs from there.

     

    Your setup should have plenty of processor and I assume with 6x120, you probably aren't storing much Video which is driving a lot of people to 500gb or larger drives.

     

    Tuesday, September 11, 2007 9:14 PM
  •  HLaRoux wrote:

    I think a lot of people are finding that when you start looking at buying bigger drives, they want SATA which their old hardware may not support. And then they look at the 200watts their old P4 draws and see the 60watts of the new processors and then everything kind of snowballs from there.

     

    Your setup should have plenty of processor and I assume with 6x120, you probably aren't storing much Video which is driving a lot of people to 500gb or larger drives.

     



    I was going to put video on the server, but it won't let me put 360+GB worth of video.  Lucky for me Newegg have 750GB hard drive for $199.  I picked up 2 of these drives.  This what I love most about WHS, you can change the configuration of the drive on the fly, add a drive, remove a drive, I love it!
    Saturday, September 15, 2007 12:41 AM