rdgreenall@watnot.UUCP (Richard Greenall) (10/17/86)
<Line-eater Food>
In an article written approx. 1 weeks ago I wrote:
I was wondering if any one out there has had any experience in running
a bulletin board system off of a 20 meg hard disk. I am wondering
if the constant running of the hard disk is damaging to it. (Ex. running
approximately 20 hours. per day.)
It seems crazy to me that the hard disk should be running
when there is no activity on the board. The
ideal situation would be for the pc to start the motor on the
hard disk as soon as it detects a call on the modem. (I think this
is impossible but who knows what somebody can come up with)
Any Ideas? Has anybody tried such a project.
Do I have any idea of what I'm talking about?
Thanks
RDGREENALL@watnot.UUCP
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jmsellens@watdragon.UUCP
Organization: U. of Waterloo, Ontario
WRITES -
Common wisdom is to leave the drive on all the time. You'll do more
damage to it turning it on and off all the time than leaving it
running ...
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guzzi@uicsrd.CSRD.UIUC.EDU (Mark D. Guzzi)
WRITES -
Richard,
Although what you're saying makes perfect sense, it doesn't work
that way. Disks on mainframes run constantly--it's a fairly major thing
to spin one down, and most sites only do it if they are moving the disk.
Running a disk adds some wear and tear; it's mechanical after all. but I
think it's the starting up and the stopping that do the most damage. The
machine that I use at work stays on 24 hours a day during the work week--I
sometimes shut it down on weekends.
You certainly wouldn't want the hard disk to be spun down when not
used and then spun up when you needed it--like a floppy. A hard disk take
quite a while to get up to speed before it can be used, and it takes a
while to spin down. Besides making the hard disk slower than a floppy, I
think the acceleration and deceleration puts more strain on the disk than
running it.
These are the opinions of a user and system's person, not
a disk designer nor hardware specialist.
--Mark Guzzi
University of Illinois at Urbana-Champaign
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seismo!gatech!gitpyr!SCHEUTZOW, MICHAEL J <seismo!gatech!gitpyr!gt6294b>
Organization: Georgia Institute of Technology
WRITES -
One thing worth considering is the wear-and-tear caused during spin-up
and spin-down. I cannot judge if it is a valid comparison or not, but
it has been "proven" that you are better off leaving a PC on 24 hours
a day, rather than turning it on and off. Supposedly, the startup
current surges do horrible things to silicon devices, so it is better
to let them remain in a steady-state.
Of course, this is contrary to saving energy (etc), but life is full of
tradeoffs.
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seismo!uwvax!puff!plocher (John Plocher)
Organization: U of Wisconsin CS Dept
WRITES -
Some versions of the DEC Rainbow did that - supposed to keep heat down...
EVERYONE complained - dec finally undid that 'feature'
reason: HD takes > 30 seconds to power up, disk reads on a
stopped disk take > 40 seconds! Who of your BBS users is going
to wait 30 seconds for your BBS to respond?
The disk running 24 hours should be no problem as long as it is
well cooled (fan, vents...) Mine has been running 24 hours a day
since June 6 with NO problems...
John
--
harvard-\ /- uwmacc!uwhsms!plocher (work)
John Plocher seismo-->!uwvax!<
topaz-/ \- puff!plocher (school)
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seismo!decvax!wanginst!wang!wang7!pingel (Lee Pingel)
WRITES -
I have considered such a problem. I personally op for an entire system
power off/on with fast boot. I am building my own pwer controller to be
driven by CD from the modem. If you are interested, there is a commercial
power controller that operates the same way. I don't have the name off
hand, but will locate if you are interested.
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From: conway<cc743805@sjuvax.sju.edu> (Chuck Conway)
Organization: St. Joseph's Univ., Phila. PA
WRITES -
It seems to me that there would be a lot fewer IBM BBS systems out
there if running a hard drive 24hrs a day 365 days a year was very
detrimental to the drive. Matter of fact, I might even propose that
the strain on the drive motor would be higher if it kept cycling
off an on, than if it just ran at a constant speed all the time.
Besides, wouldn't the cycling on/off really slow down the system?
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From: timothym@tekigm2.UUCP (Timothy D Margeson)
Organization: Tektronix, Inc., Beaverton, OR.
WRITES -
Here in our department, we run three IBM PC-AT's. Each with two 20 meg disks.
Each are left on 24 hours a day. In each system there is one stock (CMI?)
drive, and one after market drive (Seagate). We have not had any problems
with the disks or computers, and we have had them over one year now. That
makes a total test time of 50,000 hours with 0 failures. Or 25,000 hours per
disk drive without failures. Not bad when you think about it.
BTW, it is my understanding that crashes are more likely during spin-up and
spin-down, as that is when the heads actually begin or stop flying over the
media.
FYI....
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