How long can we realistically expect the Hard Drives (int or ext) to perform well?

Discussion in 'DIRECTV HD DVR/Receiver Discussion' started by nsolot, Apr 11, 2012.

  1. nsolot

    nsolot AllStar

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    In PC environment, I typically replace the hard drive(s) every 3 to 5 years, depending on how critical the data.

    With my new setup with external drives and the BlacX docks, it's ever so obvious from the flashing red activity light, that drives connected to HRs are getting worked 24x7.

    What do you do? Wait for the drive to start performing poorly (or go paws up)? Or swap them out on a scheduled basis for a new drive? I'm inclined to swap my external drives every 2-3 years as part of preventative maintenance.
     
  2. cygnusloop

    cygnusloop Hall Of Fame

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    But to prevent what? Loss of your programming? That will happen anyway when you swap a new drive in, unless you go through the painful process of copying the data over to the new drive.

    Personally, I have 2 external drives. One has been chugging along for nearly 6 years, on the same HR20-700. The other about 5yrs. It however has been on a variety of HR21s and 22s. It is now on an HR24-500, and is happier than it has ever been.

    I guess my point is that in my experience, the more likely point of failure is the DVR, not the HDD. But that's just in my experience.:grin:
     
  3. BAHitman

    BAHitman Godfather

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    if data is critical or important to you, put in a RAID array. replace drives when they fail

    if data is less critical, replace drives when they fail

    in either case, keeping backups is the best defense...

    in the case of the DVR's. either use multiple DVR's to have backups, use a RAID enclosure, or do both.

    ther is no real point toh replacing a HDD before it dies. i have some drives in a RAID arrays tha have been working for 7 or more years... they will eventually fail. when they do I just swap in a newer drive and I'm done with it...
     
  4. harsh

    harsh Beware the Attack Basset

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    It isn't a case of having to replace an operating system and reloading/configuring all of your applications software. As such, there's not much point in being proactive with a DVR drive.
     
  5. Carl Spock

    Carl Spock Superfly

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    I'd ask the question as when will a hard drive fail?

    Any day now.
     
  6. BAHitman

    BAHitman Godfather

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    so right... I've seem 'em fail in as little time as it took me to get it out of the box, others that have run 24/7 for many years...
     
  7. Rich

    Rich DBSTalk Club DBSTalk Club

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    Actually, the external devices used to house the external HDDs seem to be the most likely thing to go bad. The HDDs last a lot longer than I expected them to.

    Rich
     
  8. Jerry_K

    Jerry_K Godfather

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    Internal drives still going strong in DirecTiVo after 8 years. IDE drives. Longest I have had a SATA drive running has been for three years.

    External is a crap shoot because the drive enclosure is the weak link. I had one enclosure destroy a drive, and one enclosure die without killing the drive.

    YMMV
     
  9. Richierich

    Richierich Hall Of Fame

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    Depends on a lot of things such as how Hot the Environment it is kept in is, how many times it has a sudden power Shutdown rather than a Graceful Shutdown.

    Also, who made the drive and what type of drive is it.

    There are now hard drives designed for use in DVRs that run 24/7. I would say most drives last around 5 years but could go on for 7 or 8 years depending on the factors stated above and other factors such as dependable noise free electricity.

    The Power Supply will probably go first on most DVRs which Mimics a Bad Hard Drive.
     
  10. ThomasM

    ThomasM RF Engineer

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    I've got three of them running in my 3 DVR's. One of my R15's was made in 2005 and it has the original Maxtor drive in it working fine. The other two are now about 5 years old and still bumbling along.

    I think the two most significant detriments to an HDD is moving it when it is powered up and big power glitches during storms. High temperature doesn't help either but the DirecTV receivers have fans and let you know how hot they are running.

    When the first hint of thunder is heard around here, my ENTIRE DirecTV system gets unplugged (including the multiswitch). So do all my expensive electronics (computers, TV's, stereo, etc.)

    I worked for years on radio transmitters at remote tower sites and have seen just what lightning can do (plus so-called "surge protectors" which generally get blown apart and do nothing to protect the equipment).
     
  11. TomCat

    TomCat Broadcast Engineer

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    Heat is an important factor. How it shuts down really isn't. With a rude shutdown the actuator moves to a "neutral corner" and the platters stop spinning. Nothing bad happens mechanically. THe actuator does not dive into the platters and dig a trench in the recording media.

    The risk from a rude shut down is if the drive is in write mode and a few bytes get sprayed across sectors they were not originally targeted for. This can corrupt a file or two on occasion, but unless it is a file important to operation, such as the OS, there is no real danger, and even if those files are important it only means a loss of data. If it sprays across the catalog database you could lose a lot of recordings, so it is not highly recommended to yank the power cord, but will it hurt the drive mechanically or electrically? Categorically, no.

    The jury is still out on whether a drive has a shorter life expectancy if it regularly shuts down, or if it continues to spin. Either scenario has the potential for mechanical failure; for one, the bearings wear out faster, for the other the inertia of spinup and spindown may be even worse. No one really knows.

    "Noise-free electricity" most certainly has nothing to do with it; AC is reduced to DC in every power supply, which means all spikes or frequencies much above zero Hz are completely filtered out. When noise becomes a problem is when the filter caps dry out letting ripple and other noise through, but it will play hell with your microprocessor long before your HDD will ever notice it. The early warning sign that your PS may be letting noise into the system is that the device reboots regularly. IOW, you have larger problems long before things can deteriorate to the level of threatening the chips in the HBA or HDD.

    The most definitive information is in a Google white paper (which you can google--I did) which did a comprehensive study of thousands of HDDs over an 8-year period in an enterprise environment where they are running all the time. The original report second-hand was that HDDs, after a few-month infant mortality period where many die, fail at a rate of about 8% per year, compounded. That means a HDD on its 2nd birthday will have a 16% chance of failure within the coming year, and that a HDD on its 3rd birthday will have a 24% chance of failure in the coming year, and so on, which means that once a drive gets beyond 5 years old, it has about a 50-50 chance of living to its 6th birthday, and if it makes it to 8 years, it has about a 25% chance of making it to 9 years old. It also means that a new drive has much less of a chance of ever making it that far.

    But if you read the white paper carefully (again, I did), the results are not as clear, and are not quite as easy to pin down. Google seems to say that a HDD will have a "significant chance" of failing between 3-5 years. But what is "significant"? 10%? 30%?

    Regardless, this has no impact or preventative replacement, which seems to make little sense in most applications and even less sense in a DVR application. The only similar scenario that might make sense is retiring a 3 to 4 year-old HDD, say, in September, just before the new fall season begins. But that entails swapping drives if you want to go back (a Thermaltake helps if that is what is decided).

    According to the Google study, really not so much. Every drive manufacturer (and I think there are really only 3 left) has had a run of problematic drives on occasion, but generally they are all about the same as far as shelf life. HDDS don't have "types". They run at different rotational speeds (in a DVR slower is actually better because of the heat factor), they have different chips in the controllers, they have different capacities, buffer sizes and physical sizes, but they all work in pretty much exactly the same way. Those designed for media applications don't do thermal calibration the same way, but those not designed for media will last just as long; its just that they will never perform well even out of the box in a DVR scenario.

    Actually, the HDD will probably has a life expectancy twice the normal HDD. It has no moving parts, for one thing. HDDs wear out over time; either the actuator sticks or dies, a bearing sticks, the recording surface flakes off, or there is a catastrophic failure of an electronic component. PS's degrade slowly, and then eventually die from a power surge or catastrophic failure of the voltage regulator. But the average life of a PS is still longer by far; its a solid state device while a HDD is mainly a mechanical device. But you are correct in that a degrading PS with drying filter caps will often present very much in the same way (spontaneous hangs and reboots) as a dying HDD.

    Actually Richie, I Think The Worst Threat To a HDD is Annoyingly-Improper Capitalization. ;)
     
  12. P Smith

    P Smith Mr. FixAnything

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    "The risk from a rude shut down is if the drive is in write mode and a few bytes get sprayed across sectors they were not originally targeted for."
    Nay, never happen - HDD's FW does control all the aspects and will have a few mS to cease writing and park heads e.g totally prevent the hypothetical case.
     
  13. skoolpsyk

    skoolpsyk Mentor

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    I just use a 2TB SSD myself.





    :)
     
  14. P Smith

    P Smith Mr. FixAnything

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    Another billionaire came here ... :D
     
  15. 1948GG

    1948GG Icon

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    It's really a crap-shoot. Most of the drives in the HR series are in the 300GB range, and have a fair to good reliability. The earliest (HR20-700) with 320GB drives (flip a coin pretty much as to what manufacturer), have been pretty good IF aided by some externally applied (read: laptop cooler) air flow.

    I have one which is my main LV/DVR, that has had cooling applied since day one 5+ years ago, but isn't used as my 'primary' viewing machine, but as a 'recorder only' while I use another machine to actually 'view' things. So it isn't 'tuned' to an 'active' channel (99% of the time it's on a music channel) so the amount of stress applied constantly recording is just about nill.

    The other sets, HR20-100's, I bought all at the same time some 3+ years ago, and have a much better designed cooling system, as others will attest to, but about the same size HD.

    I've run a HR with a RAID1 array (twin 2TB drives) for quite a while on one machine, and had more trouble with it than anything else (2 failures over 2 years). And this wasn't a 'home built', but a consumer available RAID0/1 box from a reputable manufacturer, the drives that failed were Samsung and Toshiba, and yes, data was lost.

    At that point, I put all the emphasis on 'off-loading' material via the Hauppague HD-PVR box, out to a RAID6 array. Since the day I put together that system, I've 'lost' ZERO.

    The only way to insure yourself against loss of programming is, simply, to get it out of the DirecTV realm and off-load it to reliable, expandable, systems.
     
  16. Jerry_K

    Jerry_K Godfather

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    Thanks for the good info Tom Cat.
     
  17. Joe C

    Joe C Godfather

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    +1

    Tom Cat, I really enjoy reading your posts, they are so informative. Keep it up !:)
     
  18. nsolot

    nsolot AllStar

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    +1 more for Tom Cat for reminding of the Google white paper which I had read a few years ago, and skimmed again.

    I agree with some of the posts and disagree with others. With an external drive setup, esp. the BlakX, cloning a disk (aka sector copy) is very simple. Currently I use free software from www.easeus.com. With a spare PC, connecting the cables takes less than 1 minute. The process is slow, 12-24 hours with the big drives. If the drive is starting to fail (for example, dropping sectors) the process can take longer, much longer, which is one reason to replace drives proactively.

    I quote from the Google white paper (bolding is mine)

    Our results confirm the findings of previous smaller population studies that suggest that some of the SMART parameters are well-correlated with higher failure probabilities. We find, for example, that after their first scan
    error, drives are 39 times more likely to fail within 60 days than drives with no such errors.
    First errors in reallocations, offline reallocations, and probational counts are also strongly correlated to higher failure probabilities.
    Despite those strong correlations, we find that failure prediction models based on SMART parameters alone are likely to be severely limited in their prediction accuracy, given that a large fraction of our failed drives have shown no SMART error signals whatsoever. This result suggests that SMART models are more useful in predicting trends for large aggregate populations than for individual components. It also suggests that powerful
    predictive models need to make use of signals beyond those provided by SMART.


    Which is consistent with my own experience. If a drive starts dropping sectors, or making unusual noises, I try to replace ASAP.

    Anecdotal stories from my own experience is similar to the Google paper. In one case, we purchased about 25 used "industrial" rack mount systems at a BK auction, and replaced all the hard drives with Quantum 10GB units, which ran fine and then a cluster of about 6 died about 3 years later. Otherwise the drives fail 1 or 2 a year. Another time we purchase 14 brand new rack mount systems, with IIRC Seagate drives, and 3 or 4 of them died within the first 3 months, we we replaced drives on all 14 systems.

    Hard drives were, by far the most common failure at our data center. Then other items with fans (Chassis fan, CPU fan, Power Supply, etc.) so in my mind, motors have a high incidence of failure relative to solid state devices (motherboards, add in cards, etc). The exception to this is the batteries in UPS, which can have an expected life of 3-5 years.

    Why replace drive proactively? For me, it's kind of like doing maintenance on the car. Sure I can wait for either to break down and fix it then. It's a matter of whether I are alone, or on the family vacation. I'm inclined to replace drives before they die not for my own viewing, but more so for the wife & kids, who scream at me when the DVR starts acting poorly.
     
  19. P Smith

    P Smith Mr. FixAnything

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    It's obvious to try remap bad sectors by specialized program (like MHDD, Victoria, etc) before attempt to copy a content. You'll spend much less time total.
     
  20. Wilhite

    Wilhite AllStar

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    :confused:
    I guess my interpretation of the symptoms of a failing hard drive aren't in line with what yours are.

    What symptoms do you see when a hard drive starts to go? My experience has been stuttering recordings, partial recordings, issues with playback, sporadic reboots and lockups. When I see a power supply go, it's pretty much that the unit either won't turn on or it won't stay on.
     

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