shreeve@hpcvc0.HP (Bob Shreeve) (06/17/87)
I have been having problems with my 30MB hard disk. Once the system has warmed up for 20 to 30 minutes the disk works fine. However, before this period the disk boots but typically has read errors reading files from the disk ( including command files!). The disk is a 30MB Seagate 238 and the controller is an Adaptec 2070A. If the system is power cycled after the 20 minute warm up period everything works fine. Therefore it seems the problem is heat related. Has anyone else had this problem? Any solutions? Thanks for your help. Bob Shreeve HP NID (503) 750-2975 hp-labs!hp-pcd!shreeve
dleigh@hplabsz.HPL.HP.COM (Darren Leigh) (06/18/87)
Did I once hear a wild rumor that the ST238 had problems if its bolts were tightened down too far? Sounds strange. Has anyone else heard anything? Darren Leigh
burton@parcvax.Xerox.COM (Philip M. Burton) (06/19/87)
While I have not heard rumors specifically about the ST 238 having problems if the screws are tightened too much, I have had actual experience with this problem before. When I worked at Fortune Systems, we used Tandon floppies, which were fine on the lab bench, but had tremendous problems in use. It turns out that the base casting wasn't even, so if you tightened the drive too much, you threw the drive out of alignment. If it could happen with floppies, it certainly could happen with rigid drives, where the tolerances are much, much tighter. Phil Burton Xerox Corp.
bruceb@telesoft.UUCP (06/19/87)
> I have been having problems with my 30MB hard disk. Once the system has > warmed up for 20 to 30 minutes the disk works fine. However, before this period > the disk boots but typically has read errors reading files from the disk ( > including command files!). The disk is a 30MB Seagate 238 and the controller > is an Adaptec 2070A. If the system is power cycled after the 20 minute warm > up period everything works fine. Therefore it seems the problem is heat > related. Has anyone else had this problem? Any solutions? > > Bob Shreeve HP NID > hp-labs!hp-pcd!shreeve I've got the same ST238 you do, Bob, and the same problems. I wanted to have my dealer fix it, however I just don't have the time he wanted to spend looking at it, so I've suffered with it for a while. After a period, you get used to it. I usually leave my system on all the time (which is really better anyhow), however if it gets real hot during the day, I'll turn it off. I agree it's related to heat; I've proven it. Recently, however, I ran DiskOptimizer on my disk and it rearranged the files enough that the majority of the 'boot-up-required' files aren't in the first few hundred sectors (where the controller thinks the bad sectors are). By the time that I get around to touching the files in that first area, it's usually okay. Interesting test: when you get booted up, run a utility like SCAV30 on your disk as soon as possible. It will let you know the sectors where you shouldn't place data. If you find a better solution - LET ME KNOW! thanks bruce bergman -- bang!- allegra!\ \ (619) 457-2700 x123 gould9! \ crash!--\ ihnp4! \ \ >--sdcsvax!---->--telesoft!bruceb (Bruce Bergman N7HAW) noscvax! / / scgvaxd! / log-hb!--/ TeleSoft, Inc. ucbvax! / / 5959 Cornerstone Court talaris!- San Diego, CA. 92121-9891 All opinions are mine. [ packet: n7haw @ n6atq-1, fido: 103!203 ]
jamesa@dadla.TEK.COM (James Akiyama) (06/26/87)
As most of you probably guessed, Seagate did have a thermal reliability
problem on many of their disk drives. They also had some problems with their
stepper motors, I believe. Since that time, Seagate has told us that they
corrected both problems (I haven't actually verified this since the disk drives
are no longer an engineering concern).
For the most part we (Tek. LA) have had good luck with the ST225 drives (from
which the ST238 was derived).
A couple of things that you might try:
1. Try backing up the fixed disk, then reformatting it with a low-level
format routine while the drive is operating at nominal temperature
(about 25 degrees C after running for approximately one-half hour). Be
sure to map out the listed bad blocks. Usually its best to map out the
entire track, although it is possible (through calculations) to derive
and map out only the affected sectors. Note that it is usually best
to format the drive with the actual controller that the drive is to be
used with (allows greatest margin on the data separation).
2. Be sure you are using the correct Write Precompensation. For the ST225,
the correct value is 12 nS. for both early and late bits from track
300 to track 614. This may be different on the ST238 (I don't have a
ST238 manual). Adaptec may have already set this value correctly.
3. Make sure your drive enclosure has adequate ventilation. The Seagate
Drives disipate approximately 15 watts and must run under 45 degrees
C. Generally this means have adequate heat conduction from the drive's
frame to the enclosure and/or providing force air circulation. I
believe that IBM's derated temperature specification for the PC's is
a result of this requirement.
4. Verify that the grounding strap is attached. This strap serves to
"bleed off" electrical charge which could otherwise cause errors during
reads.
5. If possible, verify the buffered seek pulse widths meet the Seagate
timing requirements. Buffered seek pulses MUST be between 5 uSecs and
200 uSecs for the drive to function properly in buffered mode. Note
that several disk controller chips (e.g. Western Digital WD2010)
provide a FAST seek rate (3.2 uSec for the WD2010). This fast rate
may cause the Seagate drive to "miss" pulses, resulting in a seek
error.
6. Finally, be sure the drive is reasonably shielded from stray magnetic
and electrical fields. This is especially a problem on drives which
are not mounted in an enclosed cabinet.
Also worth noting is the fact that there are reports of problems with the
Seagate ST238 and the Adaptec 2070A (as well as the WD1003-RAH). Western
Digital has told us that the problem appears to be in the Seagate Drive. I
haven't followed up on this at all. Hope this helps.
James E. Akiyama
Logic Analyzer Division
Tektronix, Inc.
P.O. Box 4600 Mail Sta. 92-725
Beaverton, OR 97075
(503) 629-1907mitch@alice.UUCP (06/26/87)
In article <4490004@hpcvc0.HP>, shreeve@hpcvc0.UUCP writes: > > > I have been having problems with my 30MB hard disk. Once the system has warmed up for 20 to 30 minutes the disk works fine. However, before this period > the disk boots but typically has read errors reading files from the disk ( > including command files!). The disk is a 30MB Seagate 238 and the controller > is an Adaptec 2070A. If the system is power cycled after the 20 minute warm > up period everything works fine. Therefore it seems the problem is heat > related. Has anyone else had this problem? Any solutions? > Thanks for your help. > > Bob Shreeve HP NID > (503) 750-2975 > hp-labs!hp-pcd!shreeve I've talked to folks at both Seagate and Adaptec about this problem, and both ends agree that the problem is due to a bug in the 2070A controller. The bug has been fixed in all boards shipped since last October, I believe. If you get in touch with Adaptec, they'll send you an upgrade kit to fix the problem. The buggy controller does indeed cause overheating of the disk, for reasons which I don't remember. Mitch Marcus