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Date:      Wed, 18 Nov 1998 13:40:48 -0500
From:      "USWW (United States Wide Web)" <unix@usww.com>
To:        freebsd-isp@FreeBSD.ORG
Subject:   Cannot Fork/kvm read:Bad address
Message-ID:  <365314B0.51BE@usww.com>

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System Configuration:
ASUS TPX4 CPU: Pentium (233.86-MHz 586-class CPU) Origin =
"GenuineIntel"  Id = 0x543  Stepping=3,
Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX>, 256 meg pc 100,
barracuda 4.3 scsi, wide controller. OS 2.2.7 FreeBSD, tried apache
1.2.6 reg and recompiled with mod perl. Increased maxusers to 253,
sommaxconn=512 in kernel. Changed login.conf to infinity for all
default, root, daemon processes and 256 meg for all mem limits.
Additions to GENERIC Kernel are at the bottom of the email.

I Still have a massive problem with "500 Internal Server Error" with
kvm_read errors running cgi's. I maintain a total of 47 machines around
the US all of them that have any anount of traffic are having these
problems. I have 5-6 locations ready to bailout and go back to Linux if
I can not solve it. I have sent Email to some groups with no response. I
have read several hundred reports about this online with no resolve.
Jordan or some one I need your help quickly. Tech support told me to
email you since they did not have an up to date phone number.

I have tried mod_perl with the same result. I tried the new 1.3.0, 1.3.1
and 1.3.2 and saw too many problems and went back to 1.2.6. What am I
missing? What is slapping me in the face that I don't see?

Here is a bit more information about the system problem it appears that
kvm is coming in to play here. Once the cannot fork error starts showing
up in the apache error log file. If I HUP apache it will work ok for
about 30 minutes. In top it appears as though I have lost memory and
vmstat is reporting major page faults. Under no conditions can I get the
kvm_read: Bad Address to re-cycle. Is there a way while the system is
running that I can re-init the kernels virtual memory? Server loads are
running at average 2.05, 3.20, 2.15.

I can fix the problem by rebooting the box it will go about 24 hour (2
million hits) before occuring again. Reminds me of a BRG (Bill Reboot
Gates) NT box which has to be re-cycled daily because it looses memory
pointers and looses rescources. 

Jordan:
Have you tried asking the true experts when it comes to this topic?
freebsd-isp@freebsd.org would be my very first avenue of recourse if
our positions were reversed.  I'd explain exactly what I was trying to
implement (# of desired simultaneous users, type of CGI script(s)
being run) along with the Apache version, OS info, hardware manifest
and other such information as you have already provided me.  The folks
in freebsd-isp don't just contemplate such problems as an abstract
challenge, as I do, they actually solve them every day.

- Jordan


## Start of mods 
# changed maxuser because http://apache.org/docs/misc/perf-bsd44.html
# also added SOMAXCONN NMBCLUSTERS cause of the same
# changed SOMAX in /usr/include/sys/socket.h, /usr/src/sys/sys/socket.h
# instead of defining here from
http://apache.org/docs/misc/perf-bsd.html
#options         SOMAXCONN=256           # set w/sysctl -w
kern.somaxconn=512
                                         # in /etc/rc.local at boot
 
options         NMBCLUSTERS=4096        # mbuf clusters at 4096
options         CHILD_MAX=512
options         OPEN_MAX=512
#added the following because 500 cgi errors occur when loaded
options         "MAXDSIZ=(256*1024*1024)"
options         "DFLDSIZ=(256*1024*1024)"
options         "MAXMEM=(256*1024)"
options         MROUTING                # Multicast routing
options         IPFIREWALL              #firewall
options         IPFIREWALL_VERBOSE      #print information about
                                        # dropped packets
options         "IPFIREWALL_VERBOSE_LIMIT=100" #limit verbosity
options         IPFIREWALL_DEFAULT_TO_ACCEPT #allow everything by
default
options         IPDIVERT                #divert sockets
options         TCPDEBUG
options         MFS                     #Memory filesystem

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