A computer components & hardware forum. HardwareBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HardwareBanter forum » General Hardware & Peripherals » Storage & Hardrives
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Failure of external HDD's - why doesn't any manufacturer wake up to this?



 
 
Thread Tools Display Modes
  #1  
Old February 16th 07, 03:31 PM posted to comp.arch.storage
richard
external usenet poster
 
Posts: 4
Default Failure of external HDD's - why doesn't any manufacturer wake up to this?

A couple of years ago I bought 4 external HDD's, Maxtors, to increase
storage capacity on some machines (and offer portability) in my business.
After 2 failed in short order I returned the other 2 and swore not to
touch external drives again.

A couple of months ago my IT supplier convinced me to try a Lacie 2T
external HDD (internally, 4 Hitachi 500G's in a raid 0 array). We were
using it to store video clips after editing, pending backup to tape.
Sure enough, it has failed and I am again in the quandry of whether to
send it back for warranty repair - risking propagation of my sensitive
files, and the best I can hope for, is a new, empty drive. Recovering
the data is at least $3,500 and I may not get it all. The drive itself
cost me $2K. ($Australian).

I'm an engineer and it is my opinion that these units are all
under-designed, thermally. Ok they have cooling fans but that means
nothing. In the case of the Maxtor units, the HDD was suspended
internally on rubber bushes and so there's no mechanical heatsinking. A
one-inch fan sucked out a little warm air but the drive itself still ran
hotter than one mounted inside a PC, where the chassis sucks up a fair
amount of heat. One type I looked at didn't even have cooling fans so
the casing was effectively a blanket!

The Lacie drive had been left on (but mostly idle) almost continuously
for the entire 3 months it was in service, and failed during a cold
start. That smacks of a thermal stress failure.

These days I always order my PC's with cooling fans mounted directly on
the HDD bay and haven't had a failure since. Put your finger near the
spindle of a HDD that has been running an hour or so and you'll find it
almost too hot to touch. Friction rises exponentially with temperature
because it's a positive feedback loop. Heat loss also rises
exponentially with temp, which stabilises at a point where they are in
balance - and the better the heat removal, the lower the temp.

HDD failure is every computer user's worst nightmare. The temperature
issues are obvious to even a novice engineer. So why, oh why, do they
continue to underdesign these things - not just in external units, but
inside PC's as well? Of course both manufacturers told me "you know we
dont' get many of these back..." (Probably something to do with their
policy that the faulty unit can't be returned and therefore you have no
hope of getting your data back, so you're better off sending it to a data
recovery service).

Who else has experienced a higher failure rate on external HHD's? Or
undercooled internals?

As far as I can tell my only solution for reliable, portable mass storage
will be to re-engineer a commercial unit to improve it's cooling - but
void its warranty. Who cares, the warranty is useless when it doesn't
cover your data.




  #2  
Old February 16th 07, 11:25 PM posted to comp.arch.storage
Bill Todd
external usenet poster
 
Posts: 162
Default Failure of external HDD's - why doesn't any manufacturer wakeup to this?

richard wrote:

....

HDD failure is every computer user's worst nightmare. The temperature
issues are obvious to even a novice engineer. So why, oh why, do they
continue to underdesign these things - not just in external units, but
inside PC's as well?


The disk manufacturers, at least, don't: the environment for which
their disks are designed is quite publicly specified, and it's hardly
their fault if those who use the disks don't pay attention to it.

Failure rates of (S)ATA units have been studied by users as well as
manufacturers: while the real-world-environment failure rates
encountered by the former (such as the Internet Archive project and the
- I'm sad to say now apparently late - Jim Gray at Microsoft) tend to be
higher than the more-carefully-controlled-environment failure rates
published by the latter, the differences aren't nearly sufficient to
support your allegation that they're 'underdesigned' for their use.

Perhaps you're just unlucky, or unusually hard on your disks, or the
design of the cases you use sucks, or you're using older disks (the
newer ones don't tend to get nearly as hot as you claim when properly
cooled: for the past several years my internal 7200 rpm Seagates have
idled at around 20 degrees C. below their nominal 55 degree C. maximum,
according to S.M.A.R.T., with no special cooling arrangements such as
you describe: the normal influx of air to the front of the drive bays
caused by the PSU fan plus a single auxiliary 80mm. fan is more than
sufficient for them).

Unless the internal air flow misses the drives, you can get a pretty
good idea of how hot disks in external cases are getting by checking
whether the exhaust-fan air feels warm (if not, the flow is probably
adequate to keep the disks cool). You noted that one of your external
cases didn't have a fan, and just acted as a 'blanket'. Maybe, maybe
not: some such cases claim to make good thermal contact with the drive
and conduct heat efficiently to their exteriors (the USB example that I
happen to have here unfortunately doesn't report S.M.A.R.T. attributes
via any of the software I have readily available - anyone know of some
software that might do this?).

In any event, don't presume to generalize from your own experience -
especially given the ease with which you could find broader relevant
information.

....

Who else has experienced a higher failure rate on external HHD's? Or
undercooled internals?


Undercooled disks certainly don't live as long - the rule of thumb is
that the life halves for every 15 degree C. rise in operating
temperature (and likely drops far faster if you exceed the nominal
maximum). Of course, external drives may also be prone to more physical
shock during operation than internal drives.

The bottom line is, keep your disks reasonably cool and free from abuse
and they won't disappoint you.


As far as I can tell my only solution for reliable, portable mass storage
will be to re-engineer a commercial unit to improve it's cooling - but
void its warranty.


Why not just look around until you find a commercial unit that cools its
disks properly? With external SATA units that should be trivial (no
problem getting the S.M.A.R.T. information there).

- bill
  #3  
Old February 17th 07, 05:27 AM posted to comp.arch.storage
_firstname_@lr_dot_los-gatos_dot_ca.us
external usenet poster
 
Posts: 4
Default Failure of external HDD's - why doesn't any manufacturer wakeup to this?

In article vpadnVkUKdnZskvYnZ2dnUVZ_uejnZ2d@metrocastcablevi sion.com,
Bill Todd wrote:
richard wrote:

...

HDD failure is every computer user's worst nightmare. The temperature
issues are obvious to even a novice engineer. So why, oh why, do they
continue to underdesign these things - not just in external units, but
inside PC's as well?


The disk manufacturers, at least, don't: the environment for which
their disks are designed is quite publicly specified, and it's hardly
their fault if those who use the disks don't pay attention to it.

Failure rates of (S)ATA units have been studied by users as well as
manufacturers.


Both large scale users (computer and storage array makers) and disk
makers have very detailed data on this. However, this data is not
shared with competitors, nor with consumers.

Several studies have been published in the open literatu

while the real-world-environment failure rates
encountered by the former (such as the Internet Archive project and the
- I'm sad to say now apparently late - Jim Gray at Microsoft)


May Jim rest in peace. I hope he died the way he wanted to. At this
point, that's the best we can hope for.

In addition to his data, this year's FAST conference (go to
www.usenet.org and search for FAST2007) had two papers on real-world
disk failure rates. The first one (by Bianca S. from Carnegie Mellon)
got best paper award, and has a lot of information about a variety of
settings. The second one (from google) has some very interesting
information about a 5-year study; unfortunately, it mixes older and
newer disks.

The second paper has some astonishing data: namely that disks live
longer if you don't keep them too cold; 30 or 40 degrees are better
than 15 or 20. We know that really cold temperatures (5 or 10
degrees) are bad for disks, but I was quite astonished by this result.
A very senior person from a disk manufacturer was sitting next to me
during this talk, and was shaking his head. The above observation
quite bady violates many things we thought we had known, and might be
an artifact of mixing different disks that use different housings in
the same data set. So don't take it too serious yet.

Please note that disk lifetime is also affected by other factors.
Such as workload: continuously seeking is bad; continuously writing
is also bad (as it increases the risk of off-track writes). This is
particularly true for consumer-grade disks (which is often but no
always synonymous with IDE/SATA disks); those are typically specified
for 40-hour-per week operation, instead of 24x7.

Disk lifetime (and error rate) is obviously affected by temperature,
except that the recent Google result above confuses that issue. It is
also seriously affected by vibration, in particular for consumer-grade
disks (again, often IDE/SATA), which can't simultaneously servo and
transfer data. For this reason, it is important to use
vibration-absorbing disk mounts, low-vibration fans, and isolate disks
from other vibrating components (such as CD-ROMs and other disks).
Mechanical shock during operation can be very very bad, so don't kick
your computer just because your program doesn't compile.

Perhaps you're just unlucky, or unusually hard on your disks, or the
design of the cases you use sucks, or you're using older disks (the
newer ones don't tend to get nearly as hot as you claim when properly
cooled: for the past several years my internal 7200 rpm Seagates have
idled at around 20 degrees C. below their nominal 55 degree C. maximum,
according to S.M.A.R.T., with no special cooling arrangements such as
you describe: the normal influx of air to the front of the drive bays
caused by the PSU fan plus a single auxiliary 80mm. fan is more than
sufficient for them).


Warning: 10K and 15K RPM SCSI/SAS/FC disks run considerably hotter
than 5400 and 7200 RPM IDE/SATA disks. Particularly true for 2.5"
enterprise-grade disks. All those disks should be equipped with a fan
that guarantees good airflow.

In any event, don't presume to generalize from your own experience -
especially given the ease with which you could find broader relevant
information.


If you want to generalize from your experience, your experience better
be based on hundreds of thousands of disks. Most home computer users
(fortunately) don't gather that kind of data.

--
The address in the header is invalid for obvious reasons. Please
reconstruct the address from the information below (look for _).
Ralph Becker-Szendy
  #5  
Old February 17th 07, 03:38 PM posted to comp.arch.storage
richard
external usenet poster
 
Posts: 4
Default Failure of external HDD's - why doesn't any manufacturer wakeup to this?

In article vpadnVkUKdnZskvYnZ2dnUVZ_uejnZ2d@metrocastcablevi sion.com,
opined thusly:


Unless the internal air flow misses the drives, you can get a pretty
good idea of how hot disks in external cases are getting by checking
whether the exhaust-fan air feels warm (if not, the flow is probably
adequate to keep the disks cool).


Without voiding the warranty how can you know? If the air is cool it is
either missing the drive or doing a good job. If the air is warm it is
either doing its job...or not, it may still be insufficient to keep the
bearing and surface temperatures down. But a 1" fan in an enclosed space
where there's no mechanical heatsinking, intuitively, isn't going to cut it.

You noted that one of your external
cases didn't have a fan, and just acted as a 'blanket'. Maybe, maybe
not: some such cases claim to make good thermal contact with the drive
and conduct heat efficiently to their exteriors


This one had the drive suspended on rubber shock mounts so it really was an
oven, a perfect way to test for heat failure.

In any event, don't presume to generalize from your own experience -
especially given the ease with which you could find broader relevant
information.


Well the purpose of my post was to find out if I'm not alone in my
experiences. Citing the above example, that brand is just going to fail over
and over - but only I guess for users who give it a duty cycle that's
light enough to keep its temp down.


The bottom line is, keep your disks reasonably cool and free from abuse
and they won't disappoint you.


As far as I can tell my only solution for reliable, portable mass storage
will be to re-engineer a commercial unit to improve it's cooling - but
void its warranty.


Why not just look around until you find a commercial unit that cools its
disks properly? With external SATA units that should be trivial (no
problem getting the S.M.A.R.T. information there).


Any suggestions? How about this S.M.A.R.T. software, does it slow down access
time? Any recommendations on whose to use?

thanks for the info.

  #6  
Old February 17th 07, 06:03 PM posted to comp.arch.storage
toby
external usenet poster
 
Posts: 6
Default Failure of external HDD's - why doesn't any manufacturer wake up to this?

On Feb 16, 11:27 pm, wrote:
In article vpadnVkUKdnZskvYnZ2dnUVZ_uejn...@metrocastcablevi sion.com,
Bill Todd wrote:

richard wrote:


...


HDD failure is every computer user's worst nightmare. The temperature
issues are obvious to even a novice engineer. So why, oh why, do they
continue to underdesign these things - not just in external units, but
inside PC's as well?

...
In any event, don't presume to generalize from your own experience -
especially given the ease with which you could find broader relevant
information.


If you want to generalize from your experience, your experience better
be based on hundreds of thousands of disks. Most home computer users
(fortunately) don't gather that kind of data.


Richard's observation that common-or-garden external enclosures are
underdesigned is likely quite valid. Although one should perhaps spend
commensurately with the value of one's data, not just on enclosure,
but also on redundancy.

It's also usually true that software could make better use of SMART
data and other early warning signs (I believe this is on Solaris' ZFS
and Fault Management roadmap).

http://www.opensolaris.org/os/community/fm/
http://blogs.sun.com/eschrock/date/20051121


--
The address in the header is invalid for obvious reasons. Please
reconstruct the address from the information below (look for _).
Ralph Becker-Szendy



  #7  
Old February 17th 07, 10:39 PM posted to comp.arch.storage
Bill Todd
external usenet poster
 
Posts: 162
Default Failure of external HDD's - why doesn't any manufacturer wakeup to this?

richard wrote:
In article vpadnVkUKdnZskvYnZ2dnUVZ_uejnZ2d@metrocastcablevi sion.com,
opined thusly:

Unless the internal air flow misses the drives, you can get a pretty
good idea of how hot disks in external cases are getting by checking
whether the exhaust-fan air feels warm (if not, the flow is probably
adequate to keep the disks cool).


Without voiding the warranty how can you know? If the air is cool it is
either missing the drive or doing a good job. If the air is warm


Actually, the air shouldn't be more than luke-warm, because then the
disk would be even warmer. Moving air feels cooler than still air, so
if the disk is, say, 12 - 14 degrees C. above room temperature (as my
Seagates seem to tend to run; a couple of WDs that I checked ran a
little warmer) the exhaust air (at a slightly lower temperature) should
barely feel warm at all.

it is
either doing its job...or not, it may still be insufficient to keep the
bearing and surface temperatures down. But a 1" fan in an enclosed space
where there's no mechanical heatsinking, intuitively, isn't going to cut it.


Our intuitions differ, then (or perhaps it's the disks we're used to
using - mine tend to run only slightly warm to the touch).

....

Well the purpose of my post was to find out if I'm not alone in my
experiences. Citing the above example, that brand is just going to fail over
and over - but only I guess for users who give it a duty cycle that's
light enough to keep its temp down.


Heavy seek loads are the worst. Video loads tend to use long accesses
with relatively few seeks: while the disk head still has to follow the
track, far less heat should be generated (I'd tend to suspect much
closer to an idle level than to a heavy-seeking level).

....

Why not just look around until you find a commercial unit that cools its
disks properly? With external SATA units that should be trivial (no
problem getting the S.M.A.R.T. information there).


Any suggestions? How about this S.M.A.R.T. software, does it slow down access
time? Any recommendations on whose to use?


Modern disks include firmware that monitors their own operation and
health, one of the outputs being their internal temperature. S.M.A.R.T.
monitoring software just interrogates the disk to get that information
out of it: there's no overhead at all save at the times you ask the
disk a question (which shouldn't be that often unless you want to use
the software to monitor temperatures for unusual changes rather than
simply check them occasionally).

I use a small free utility called Dtemp from
http://private.peterlink.ru/tochinov/ and just start it up once in a
while to see how things are doing (it reports a lot of other S.M.A.R.T.
attributes too - Seagate drives are a little strange, since they come
from the factory with non-zero values for some failing-health
indicators, according to another S.M.A.R.T. utility from Adenix that I
use less often). A quick look around turned up some other free
utilities but none that could work through a USB connection (still
hoping that someone here knows of one) - nor did the few paid-for
utilities that I encountered claim to do so.

- bill
  #8  
Old February 18th 07, 04:13 AM posted to comp.arch.storage
richard
external usenet poster
 
Posts: 4
Default Failure of external HDD's - why doesn't any manufacturer wakeup to this?

In article ,

Thanks for that info Bill. OK since the Maxtor external drive I have on my
home PC is out of warranty I just opened it up. Drive is suspended on
neoprene(?) shock mounts. The only metal-to-case contact is via a copper
earthing strip. Ventilation is a few square cm at the front and perhaps one sq
cm at the back. Fan? Nil. This is going to cook - esp as it ages.

opined thusly:


richard wrote:
In article vpadnVkUKdnZskvYnZ2dnUVZ_uejnZ2d@metrocastcablevi sion.com,
opined thusly:

Unless the internal air flow misses the drives, you can get a pretty
good idea of how hot disks in external cases are getting by checking
whether the exhaust-fan air feels warm (if not, the flow is probably
adequate to keep the disks cool).


Without voiding the warranty how can you know? If the air is cool it is
either missing the drive or doing a good job. If the air is warm


Actually, the air shouldn't be more than luke-warm, because then the
disk would be even warmer. Moving air feels cooler than still air, so
if the disk is, say, 12 - 14 degrees C. above room temperature (as my
Seagates seem to tend to run; a couple of WDs that I checked ran a
little warmer) the exhaust air (at a slightly lower temperature) should
barely feel warm at all.

it is
either doing its job...or not, it may still be insufficient to keep the
bearing and surface temperatures down. But a 1" fan in an enclosed space
where there's no mechanical heatsinking, intuitively, isn't going to cut it.


Our intuitions differ, then (or perhaps it's the disks we're used to
using - mine tend to run only slightly warm to the touch).

...

Well the purpose of my post was to find out if I'm not alone in my
experiences. Citing the above example, that brand is just going to fail

over
and over - but only I guess for users who give it a duty cycle that's
light enough to keep its temp down.


Heavy seek loads are the worst. Video loads tend to use long accesses
with relatively few seeks: while the disk head still has to follow the
track, far less heat should be generated (I'd tend to suspect much
closer to an idle level than to a heavy-seeking level).

...

Why not just look around until you find a commercial unit that cools its
disks properly? With external SATA units that should be trivial (no
problem getting the S.M.A.R.T. information there).


Any suggestions? How about this S.M.A.R.T. software, does it slow down

access
time? Any recommendations on whose to use?


Modern disks include firmware that monitors their own operation and
health, one of the outputs being their internal temperature. S.M.A.R.T.
monitoring software just interrogates the disk to get that information
out of it: there's no overhead at all save at the times you ask the
disk a question (which shouldn't be that often unless you want to use
the software to monitor temperatures for unusual changes rather than
simply check them occasionally).

I use a small free utility called Dtemp from
http://private.peterlink.ru/tochinov/ and just start it up once in a
while to see how things are doing (it reports a lot of other S.M.A.R.T.
attributes too - Seagate drives are a little strange, since they come
from the factory with non-zero values for some failing-health
indicators, according to another S.M.A.R.T. utility from Adenix that I
use less often). A quick look around turned up some other free
utilities but none that could work through a USB connection (still
hoping that someone here knows of one) - nor did the few paid-for
utilities that I encountered claim to do so.

- bill


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WD External hard disk failure... Jay Storage (alternative) 35 December 17th 05 03:28 AM
Maxtor External Drive Failure [email protected] General 5 October 5th 05 09:22 PM
Can I put 4 IDE HDD's, 2 Sata HDD's and 3 DVD drives on an A8N-SLI Deluxe? Paul Asus Motherboards 19 July 1st 05 04:54 AM
Failure of monitor to wake-up when PC does. Russell W. Barnes Compaq Computers 5 October 20th 04 08:34 PM
Keyboard failure (Power/sleep/wake) Euh General 0 December 4th 03 04:06 PM


All times are GMT +1. The time now is 06:52 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 HardwareBanter.
The comments are property of their posters.