Kernel-3.10.0-957.el7_bad_memory

March 2008
Jan-Simon Moeller, dl9pf@gmx.de

How to deal with bad memory e.g. reported by memtest86+ ?
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There are three possibilities I know of:

1. Reinsert/swap the memory modules

2. Buy new modules (best!) or try to exchange the memory
   if you have spare-parts

3. Use BadRAM or memmap

This Howto is about number 3) .

BadRAM
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BadRAM is the actively developed and available as kernel-patch
here: http://rick.vanrein.org/linux/badram/

For more details see the BadRAM documentation.

memmap
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memmap is already in the kernel and usable as kernel-parameter at
boot-time. Its syntax is slightly strange and you may need to
calculate the values by yourself!

Syntax to exclude a memory area (see kernel-parameters.txt for details):
memmap=$

Example: memtest86+ reported here errors at address 0x18691458, 0x18698424 and
some others. All had 0x1869xxxx in common, so I chose a pattern of
0x18690000,0xffff0000.

With the numbers of the example above:
memmap=64K$0x18690000
or
memmap=0x10000$0x18690000