Setting up 1/4 of memory of virtualbox on vagrantfile - vagrant

Question

I'm new on vagrant and I'm trying to put my machine to 1/4 of system memory like this:
config.vm.define "UbuntuServer2" do |server2|
server2.vm.box = "ubuntu/trusty64"
server2.vm.provider :virtualbox do |vb|
vb.customize ["modifyvm", :id, "--cpuexecutioncap", "50"]
vb.customize ["modifyvm", :id, "--memory", 'echo -n $($(awk '/MemTotal/' {print $2} /proc/meminfo / 1024 / 4))']
end
end
But i'm getting this error:
Path:
Line number: 38
Message: NameError: uninitialized constant MemTotal
How I can init this variable?
I'm using MacOs 10.11.5
Thanks in advance.

Answer 1

Here's what I am using in such case if your host OS is mac
config.vm.define "UbuntuServer2" do |server2|
server2.vm.box = "ubuntu/trusty64"
server2.vm.provider :virtualbox do |vb|
vb.customize ["modifyvm", :id, "--cpuexecutioncap", "50"]
mem = `sysctl -n hw.memsize`.to_i / 1024 / 1024 / 4
vb.customize ["modifyvm", :id, "--memory", mem]
end
end
I got a more complete script that can help anyone if needed
config.vm.provider "virtualbox" do |v|
host = RbConfig::CONFIG['host_os']
# Give VM 1/4 system memory & access to all cpu cores on the host
if host =~ /darwin/
cpus = `sysctl -n hw.ncpu`.to_i
# sysctl returns Bytes and we need to convert to MB
mem = `sysctl -n hw.memsize`.to_i / 1024 / 1024 / 4
elsif host =~ /linux/
cpus = `nproc`.to_i
# meminfo shows KB and we need to convert to MB
mem = `grep 'MemTotal' /proc/meminfo | sed -e 's/MemTotal://' -e 's/ kB//'`.to_i / 1024 / 4
else
cpus = `wmic cpu get NumberOfCores`.split("\n")[2].to_i
mem = `wmic OS get TotalVisibleMemorySize`.split("\n")[2].to_i / 1024 /4
end
v.customize ["modifyvm", :id, "--memory", mem]
v.customize ["modifyvm", :id, "--cpus", cpus]
end