avast, /proc/sys/kernel/shmmax is insufficient for avast to run

[Silviu C.]

Avast for linux requires a higher value in order to be able to update its signature database. This is the info they post on their forum to help people fix the issue:

"Starting with the 400.vps, version 100328-1, one of it's internal block reached the inner limit 33554432 bytes. It's a kernel variable which
is (quite artificially) limiting the maximum size of any SHM memory block - and 33554432 was a default for some kernels.

Solution? Set the limit to higher values (as root):

sysctl -w kernel.shmmax=128000000
OR
echo 128000000 >/proc/sys/kernel/shmmax

Place those lines to /etc/init.d/rcS or equivalent file (it's distribution-specific a bit - see /etc/inittab, the sysinit runlevel) to have them set automatically (just after boot)."

The current value in Ubuntu 10.04 is:
silviu@silviu-lucid:~$ cat /proc/sys/kernel/shmmax
33554432

Is there any reason to have this default and not something along the lines that the Avast staff suggest. Could future Ubuntu releases have "128000000" as default ? Would be nice if newbie switchers could just fire off their on demand scanner and have it work out of the box.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-image (not installed)
Regression: No
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.38-10.46~lucid1-generic 2.6.38.7
Uname: Linux 2.6.38-10-generic x86_64
NonfreeKernelModules: nvidia
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: PCH [HDA Intel PCH], device 0: ALC892 Analog [ALC892 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: silviu 1428 F.... pulseaudio
 /dev/snd/pcmC0D0p: silviu 1428 F...m pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'PCH'/'HDA Intel PCH at 0xfb500000 irq 52'
   Mixer name : 'Realtek ALC892'
   Components : 'HDA:10ec0892,1043841b,00100302'
   Controls : 32
   Simple ctrls : 18
Date: Sat Aug 6 18:49:08 2011
HibernationDevice: RESUME=UUID=95018fd9-2d30-4d41-abf1-e925fe91c88e
InstallationMedia: Ubuntu 10.04.3 LTS "Lucid Lynx" - Release amd64 (20110720.1)
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.

 eth1 no wireless extensions.
MachineType: System manufacturer System Product Name
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.38-10-generic root=UUID=a2bed996-5e17-4f52-b8db-274d9ee35737 ro quiet splash
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.34.7
RfKill:

SourcePackage: linux
dmi.bios.date: 05/09/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1013
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: P8P67 LE
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev X.0X
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1013:bd05/09/2011:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP8P67LE:rvrRevX.0X:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer

[John Russell (jrussell-88)]

These settings will not remain after the next reboot unless they are saved in the /etc/sysctl.conf file.

Open /etc/sysctl.conf in a text editor and add entry:
kernel.shmmax=128000000

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