Avast suddenly won't open

I have been using Avast on my ubuntu PC for two years. I reset the kernel to 128000000. It worked like a charm until last night. In the middle of downloading the update, an “invalid argument” icon appeared. Since then it won’t start, even after I reinstalled it.

Just to be clear, i get the “invalid argument” icon every time.

Hi MattGood, I encountered the same error after 26Mar2014. My last working 400.vps was dated 26Mar2014.

Within the context of http://forum.avast.com/index.php?topic=57775.0 , I revised the Shmmax value to 133120000 and avast started

to work again.

Perhaps one of the moderators can shed light on this matter.

Best regards.

Thank you! It’s working.

I’m curious where you got the new value. It doesn’t seem to be mentioned in the thread you posted.

I guess it would be convenient if Avast could send out some kind of notification.

Hi MattGood,

It’s just an small increase to the Shmmax value to 128000000 + (5000kbytes x 1024) = 133120000 and then try-out in a spare box. ;D

Best wishes

Hi MattGood,

Just an update, it appears that this issue has been covered before within this forum :

http://forum.avast.com/index.php?topic=57764.0

In order to accomodate future increase in the 400.vps database internal block size

(re : http://forum.avast.com/index.php?topic=57764.msg486989#msg486989 ),

I have now revised the shared memory block size maximum limit of my Ubuntu/Linux Mint machines to:

shmmax = 268435456 (256Mbytes x 1024 x 1024)

which is about 1/16 of my 4GM RAM machine and 1/8 of my other 2GB RAM machine.

So far so good.

Best regards

Thank you. What is the terminal command for changing the value permanently?

Hi MattGood,

To recap:

a) The default maximum size of a shared memory block segment or shmmax is set in the linux kernel (32Mb in the case of Ubuntu) by the linux kernel maintainers? (i.e hardcoded).
b) However, this shmmax value can be revised via issuing the command after the boot up process:

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

To automate the process, see : http://forum.avast.com/index.php?topic=57775.msg486945#msg486945.

c) The value of the shmmax can be revised e.g from 128000000 to 133120000 or a higher value as time goes by to accommodate later changes in vps.400 (avast definitions).
d) I am setting the shmmax value to as high as I think it will work in order to minimise this issue from recurring again.
f) As long as this limitation is in play between avast vps.400 and the shmmax limit, we will encounter the same error in the future when it is exceeded.
g) My guess is this solution is a “workaround”.

Best Regards

Sorry to re-open the thread but after carefully looking at the remedies proposed, I’m still unable to launch Avast (getting the message invalid argument - I downloaded Avast today). I changed in the terminal the default value for shmmax to 128000000 (and even later to a higher one) as suggested in this thread but nothing changes.

I don’t know if there is something new about.

I’m under Ubuntu 14.04 LTS.

Thanks

PS: to be more precise, I can launch Avast if I delete the file 400.vps in the terminal. Then I launch the definition update and it ends up in “reinitialization of avast engine failed after the database update - the application will terminate” plus “An error occurred in avast ! Argument invalid”; checking in the terminal the file 400.vps is back.

I’m having the same issue with Ubuntu 14.04.

I applied the changes prescribed but still receive the error.

Below follow the procedure for error to start avast:

My machine is a “Dell Inpiron” with 4GB of memory, and Ubuntu Linux 13.10.

This solution will work for computers with higher memory not low ones.

Insert

SHMMAX=sysctl -n kernel.shmmax
[ $SHMMAX -lt 128000000 ] && sysctl -w kernel.shmmax=128000000

in /usr/lib/avast4workstation/bin/wrapper-script.sh

Then open terminal and type

sudo sysctl -w kernel.shmmax=200000000

Hit Enter.

And then start avast.

Now Avast works!