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Title: General hardware problems

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General hardware problems
Symptom:
One ore more of the following phenomena occur :
- Timing problems when accessing the CD-Rom (halt,long delays, bus errors, segmentation faults)
- kernel generation (or compilation of other programs) aborts with signal 11
- kernel generation (or compilation of other programs) aborts with signal 7
- Incorrect file contents
- Memory access errors
- Graphics are not displayed correctly
- crc-errors when accessing the floppy disk drive
- Crashes or halts during boot-up
- Errors when creating a filesystem (mke2fs reports errors)
Cause:
These strange phenomenona are most probably down to faulty or wrongly
configured hardware.
The reason for this is that many motherboards apparently have
timing problems. These timing problems become visible through
bus errors (CPU-memory-PCI-ISA).
Even if the system is stable under DOS or Windows, for example, this
doesn't say anything about the stability of the hardware
and its configuration. The hardware manages to work with the slow
segmentated memory access of a CPU working in 16 bit realmode (under
DOS, Windows). As soon as the memory is accessed in linear mode with
32 bit bursts, errors can occur.
A further cause can be a badly cooled CPU or too slow or faulty (heat-sensitive)
RAM modules (SIMMS).
The cause lies quite clearly, then, with the hardware, and not with Linux.
Linux requires more hardware stability than other operating systems do.
On the one hand this provides increased performance. On the other hand
it can lead to the above mentioned problems on some systems. In contrast to
other operating systems Linux assumes that the hardware works properly and is stable. If this
is not the case Linux stops working.
An operating system that still runs with faulty or potentially faulty
hardware represents a severe security risk.
Remedy
There are a number of parameters and conditions that can be changed
in order to isolate the faulty equipment.
- Switch off the internal and/or external Cache using the BIOS setup (CMOS)
- Reduce the bus clock (VLB maximum 40MHz !
PCI bus according to the specification maximum
66 MHz ext. processor clock) : use BIOS setup or jumpers on the mainboard.
- Add waitstates : use BIOS setup
- In (Advanced) Chipset Setup, if available,
set
CAS before RAS
: use BIOS setup
- Test the memory :
-
There will always be problems where modules of different kinds are
used together!
- When using a PCI-bus with 66 MHz the DRAM modules must
be specified with 60ns or less (no overtiming).
- Check the fittings of the SIMMS or DIMMS, they must fit exactly and must
not be loose or tilt. Remove the modules from the board and put them back in
(check for corroded contacts).
- Change the order of the modules in the memory banks.
- Check that the CPU fan is working and whether it really fits
exactly on the CPU (if necessary use heat transfer paste)
- Switch off Power Management (APM). This was noticed several times as a
source of errors,
particularly in conjunction with the 2940 : use the BIOS setup.
- Some Pentium clones cause problems if the kernel or the compiler were
optimized for the Pentium but a K6 or a Cyrix 6x86 is used instead.
On such a system you have to optimize the kernel and the
programs for a 486 at the maximum. If might even be necessary to fall back to 386 optimization.
- Check all general BIOS settings. If necessary revert to the (rather
conservative) BIOS defaults.
- If you have a buggy PC-BIOS the only solution is a BIOS update.
Ask your local dealer or the manufacturer of the mainboard. See also the article
"Motherboard Chaintech 5IFM-0 causes problems" maddin_ifm0.html
- The power supply doesn't provide enough electricity or the voltage fluctuates : Try switching off some other appliances.
Further information:

See also:

Keywords: HARDWARE, APM, 2940, INCONSISTENT DATA, INEXPLICABLE, SIG11, SIGNAL11, SEGMENTATION FAULT, POWER MANAGEMENT, MKFS, MKE2FS, CRC

Categories:
Frequently asked Questions
, Hardware

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SDB-kfr_58, Copyright SuSE GmbH, Nuremberg, Germany
- Version: 12. Mar 1998
SuSE GmbH - Last generated: 07. Oct 1999 16:55:32
by maddin
with sdb_gen 1.00.0