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Old 01-16-2008, 04:09 PM
DoN. Nichols
 
Posts: n/a
Default Re: 6 bay scsi enclosure. overheating?

According to james <at>:
> DoN. Nichols wrote:
> <snip>
> > Does the fan work? (Can you feel air being blown out the back
> > when you turn it on?)

>
> yes. both are pushing quite a bit of air
>
> > Is the box clogged with housedust? Ours tend to accumulate cat
> > hair and dust with a few years of continuous operation.

>
> it's sitting in an open back "cubby hole" in my desk about 3 feet off
> the ground so there wasn't much dust at all when i opened it up a couple
> of days ago, but i blew it out anyway.


O,K. So that is eliminated, assuming that the fans in the box
still run -- which your statement above suggests.

> i actually ended up leaving the
> side pannel part way open and putting a fan in front. it works for
> about 30 minutes this way and when it starts it's "cycle" it goes about
> 2 minutes before crapping out again.
> cheesy top view ascii art follows:
>
> ____
> /| |
> / | | <--drives
> ----
>
> /-----\
> \-----/ <--fan
>
> > There are some software packages out there which will report the
> > temperature that at lest some of the drives sense.

>
> i didn't know that there were any drives that reported temp... any
> pointers?


I've been trying to remember. IIRC, someone posted to this
newsgroup within the last year a fairly simple C program which reads that
information. And, I think that it may also report the temperature at
which it decides to shut down as well. I compiled it, and it worked
nicely, but I now forget its name. (One of the hazards of having
programs without man pages. :-)

One thing which is a major superset of that is:

smartmontools-5.33

which might be a good idea while running striped disks anyway.

> > Note that I am not running it as a stripe, but rather as
> > individual filesystems under Solaris 10, which may have some impact on
> > things.

>
> the only difference i can think if is that these 18 gig drives are
> double height 3.5" rather than the little 4 giggers that were in it. i
> pulled them out of an AlphaServer 1200 that started having /issues/
> (hince the other DEC enclosuer i have).


Hmm ... so you are using the 1" high spuds to mount the drives.
I have some which came with 9GB drives which include an extra barrier to
make the front the same height as the drives.

The numbers on an example of that style are:

0020772-9750C48359

and

5402951-02

The latter looks more like a Sun part number, but I'm not sure whether
it refers to the combination of the drive and the spud, or the spud
alone.

The former number is on the drive's label as well -- for a
Seagate ST19171WC.

Note that there is another multipack which looks just like what
you have, except that it has more LEDs on the front, and it can accept
twelve of the 1" high drives, instead of six of the 1.6" high drives.

I think that the drive should have a matching height spud, to
make the cooling better.

Note that I have had some 1" 18GB drives which would shut down
from heat in an Ultra-2, while the are quite happy in the 12-slot
Multipack.

> the way FreeBSD does the stripe is that one sector is on one drive the
> next is on the next drive and so on before going back to the first one
> so it spreads the load pretty evenly across all the drives and, therfore
> reading/writing at the same time across the file system /should/ be more
> efficient. this just adds to the confusion on 1 particular drive or
> another causing the issue since any 1 disk is only getting 1/6 of the load.


But -- it *may* translate to all six drives being run at full
speed, if the data transfer path (and the CPU) are fast enough to accept
all six drives worth of maximum throughput. In that case, there would
be more heat generated than with a single drive being run at maximum
throughput at a time.

I would be tempted to find six of the 1" 18GB drives to replace
your 1.6" ones. Start by replacing the one which overheats, as it may
simply have a lower overtemperature threshold. If necessary, replace
them all. The 1" disks typically run cooler than the 1.6" ones of
similar capacity.

Good Luck,
DoN.



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