🚀 go-pugleaf

Hi,

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....

-- 
Tim Margeson (206)253-5240
PO Box 3500  d/s C1-937                          @@   'Who said that?'  
Vancouver, WA. 98668
{allegra..inhp4..decvax..ucbvax}!tektronix!tekigm2!timothym 

I could be wrong, but it seems to me that it might be more damaging
to constantly spin your hard disk up and down than it would be to
just keep the thing running all the time.  Don't hard disk heads generally
"float" above the disk surface, rather than touch it (as is the case
with floppies)?  My 20M hard disk frequently runs 24 hours a day, 7 days
a week, and generally runs just fine.  (I say "generally" because it's
a CMI drive in a PC-AT, and has a family history of hard errors.)

bill frolik
hp-pcd!bill
Hewlett-Packard Portable Computer Division
Corvallis, Oregon

In article <12068@watnot.UUCP> rdgreenall@watnot.UUCP (Richard Greenall) writes:
>      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.) 

Yep!  I run a BBS using a PC-XT, with two 20MB drives in it.  One is for
work stuff and the other for the BBS.  Before that I had two 10MB drives
in the XT, which ran for over a year for 24 hours a day.  The current drives
have only been in about 6 months.  They too run for 24 hours a day.  Yesterday
I had to low-level format the BBS drive.  The drive started to take hits, ie,
it would error when reading data.  Everything seems fine now.

Because the drives run 24 hours a day, I use a program called TIMEPARK which
parks the heads after 1 to 9 minutes (user selectable).  That keeps the
heads off the work area while nobody is on the system and since the work
drive is spinning, it isn't accessed, it parks that one as well.

I wouldn't worry about drives spinning 24 hours a day.
-- 
		  ihnp4------\
		harvard-\     \
Mr. Video	   seismo!uwvax!nicmad!brown
		  topaz-/     /
		 decvax------/

If the disk has decent bearings its better for the disk to run
continuously throughout its life, but if the manufacturer skimped
on bearings thats different. It just depends what the weak link is.

In article <897@nicmad.UUCP> brown@nicmad.UUCP (Mr. Video) writes:
>In article <12068@watnot.UUCP> rdgreenall@watnot.UUCP (Richard Greenall) writes:
>>      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.) 

	The original bbs, CBBS-Chicago has been running 8 years, the last
6 on a 15 meg HD in a s-100 box *continuously* but for one power outage
about 3 years ago.  Also, my 3b2 has been running with standard PC type
80 meg disks for over a year.  I believe the general opinion is that
hard disks like to run, and spinning them up and down is what leads to
failures.

-- 
.. that's the biz, sweetheart...
Randy Suess
chinet - Public Access UN*X
(312) 545 7535 (h) (312) 283 0559 (system)
..!ihnp4!chinet!randy

In article <644@chinet.UUCP> randy@chinet.UUCP (Randy Suess) writes:
>...  I believe the general opinion is that
>hard disks like to run, and spinning them up and down is what leads to
>failures.

And, in general, that seems to be the consensus gathering on this topic.

BUT:	1) What about drives on their sides?  I assume disk drives are
	   designed to be run horizontally.  Do you get problems due to
	   the one-sided weight distribution?
	2) Are there any disk drive engineers listening?  You guys know
	   what's up.  What are your design objectives?  Are disks
	   designed such that it's better for them to spin indefinitely
	   rather than being turned on and off?  Is it the same story
	   for 10Mb disks as it is for 80Mb disks, or are the design
	   considerations different?

Thanks.

-Dean   (dean@ruby.berkeley.edu)

In article <12068@watnot.UUCP> rdgreenall@watnot.UUCP (Richard Greenall) writes:
>      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.) 

Actually the power up sequence is the most likely to damage you disk.
When the disk is up to speed, the heads fly just off the platter and
there is no wear. Most hard disks, particularly the less expensive
models, have a "landing zone", which is where the heads land on the
surface of the platter when powered down. Needless to say this is
always a good time to have backups.

We have a number of XTs where I work which have been powered up for
about four years now. At one time one of the repair technicians
determined that the failure rate for PCs and terminals was lower in
terms of failures per calendar year with the machine left powered up
all the time.

Disclamer: this represents personal opinion and experience only.
-- 
	-bill davidsen

	seismo!rochester!steinmetz!--\
       /                               \
ihnp4!              unirot ------------->---> crdos1!davidsen
       \                               /
        chinet! ---------------------/        (davidsen@ge-crd.ARPA)

"Stupidity, like virtue, is its own reward"

In article <12068@watnot.UUCP>, rdgreenall@watnot.UUCP (Richard Greenall) writes:
> 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)

I can see where you are coming from, but this would be worse, for a
number of reasons.

1) Although the heads contact the disk surface for floppies, for hard
disks they fly above the surface of the disk, separated by a small air
space.  There is no wear on the surface on the disk while it is
spinning or being accessed.

2) A hard disk has a lot of inertia.  When you start the motor on a
floppy drive, the system typically waits for a second or less for the
floppy to "come up to speed".  This can take up to a minute on a
typical small (20MB) hard disk.  Even after this amount of time, the
rotational speed won't be quite as stable as it will after it has been
running for a long period of time.

3) The shocks to the drive mechanism and to the disk platters
themselves from slowing down, stopping, and coming back up to speed
are significant.  They can, after time, cause mechanical problems and
can knock loose any foreign particles that might be safely tucked in a
crevice somewhere.

4) Winchester-type disks are *designed* to be constantly running.  On
large multi-user systems, with disks up to 14" in diameter, the drives
run 24 hours a day, 365 days a year, constantly; "spinning down" the
disk is a rare event.  When designing hard disks for microcomputers,
the designers have to take into account that the disk will be powered
up and down quite often (once or twice a day), and make it more rugged
to withstand that.

In summary, please *don't* try to start and stop your hard disk like
that.  And for anyone who has a system with a hard disk: don't turn it
on and off many times a day if you can help it.  I have an XT that I
turn on and off daily, and an AT that has been running for months
without being powered down.  (The AT is running XENIX, and I want to
leave it up at all times to pick up mail and such.)

John Owens		General Electric Company - Charlottesville, VA
jso@edison.GE.COM	old arpa: jso%edison.GE.COM@seismo.CSS.GOV
+1 804 978 5726		old uucp: {seismo,decuac,houxm,calma}!edison!jso

> ...  I believe the general opinion is that
>hard disks like to run, and spinning them up and down is what leads to
>failures.
>Randy Suess
>chinet - Public Access UN*X
>(312) 545 7535 (h) (312) 283 0559 (system)
>..!ihnp4!chinet!randy


I'll buy the argument that hard disks like to run, but do *PC's* like
to run as well? I'd like to keep my AT running all the time, but can
anyone tell me which if any other parts might go first? Is this an
issue with these machines? I sure would appreciate the input,
especially since my original CMI bit the dust not too long ago, and I
would like to maximize the life of the replacemnet drive (Seagate).

-- 
Charles Blair   			    ..!ihnp4!gargoyle!sphinx!cjdb
The University of Chicago		    lib.cb%chip@UChicago.Bitnet

Request for info on running PC/AT 24hr/day from:
>Charles Blair   			    ..!ihnp4!gargoyle!sphinx!cjdb
>The University of Chicago		    lib.cb%chip@UChicago.Bitnet

I have run my PC since November 1984 with the following problems:
	1) disk controller died in the 1st month
	2) CMI hard drive died at 1 1/2 years (replaced with Segate)
	3) Power supply died at last month.

The power supply was a blown fuse I think but it was inside the shield and I
left it up to XEROX (under contract) to decide how to fix it.