Re: "Out of Memory: Killed process" errors on server running Oracle or VMware

[Eric Sisler <esisler westminster lib co us>]

My apologies to Gene (the OP) for inadvertently hijacking this thread,
which was certainly not my intention. Once I have a solution I'll repost
a summary to this list & the RHEL4 list.

> If you decide to try hugemem or 64-bit I'd be interested in those
> results.

Here they are:

The hugemem kernel makes a pretty big difference.  Test server w/8Gb RAM
running the regular 32-bit kernel:

Kernel    HighTotal    LowTotal     MemTotal
----------------------------------------------
regular   7470840 kB    837724 kB   8308564 kB
hugemem   5242872 kB   3063376 kB   8306248 kB

Not sure why the MemTotals don't exactly match, I'm thinking it may be
overhead imposed by the hugemem kernel.  I was unable to run the server
out of low memory when running the hugemem kernel, so protecting it via
lower_zone_protection probably isn't necessary.  The hugemem kernel is
available for RHEL3, so perhaps this would be a good solution for the
OP, where lower_zone_protection isn't an option?

I also wiped the box & installed 64-bit RHEL4, which apparently treats
all memory as low memory, at least on my 8Gb test box:

# egrep 'Mem|Low|High' /proc/meminfo
MemTotal:      8162488 kB
MemFree:       4928372 kB
HighTotal:           0 kB
HighFree:            0 kB
LowTotal:      8162488 kB
LowFree:       4928372 kB

BTW - the free command may be a bit easier to read:

# free -lm
             total       used       free     shared    buffers     cached
Mem:          7971       3158       4812          0         83       2864
Low:          7971       3158       4812
High:            0          0          0
-/+ buffers/cache:        210       7760
Swap:        11727          0      11726

No problems thus far with this configuration either (knock wood).  As a
final test, I need to install 64-bit RHEL4 on my server w/16Gb RAM and
see if all the memory is still reported as low.

-Eric

-- 
Eric Sisler <esisler westminster lib co us>
Library Network Specialist
Westminster Public Library
Westminster, CO USA

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