Create and test speed of RAM disk on Ubuntu Linux

Make a Simple RAM disk:

Create the directory location you want to mount:
mkdir /media/ram
mount -t tmpfs -o size=1G tmpfs /media/ram/

Test how fast it is to write to it:
dd if=/dev/zero of=/media/ram/zero bs=4k count=10000

Test how fast it is to read from it:
dd if=/media/ram/zero of=/dev/null bs=4k count=10000

Remove your test file:
rm /media/ram/zero

If you want to create it again when you reboot:
vi /etc/fstab
none /media/ram tmpfs defaults,size=1G 0 0

Ubuntu 12.04 VLAN trunk to OpenWRT 10.03.1 router

sudo su
apt-get install vlan
vconfig add eth0 2
vconfig add eth0 3
vconfig add eth0 4
ifconfig eth0 0.0.0.0
ifconfig eth0 mtu 1504
dhclient eth0.2
ifconfig eth0.2 mtu 1500
dhclient eth0.3
ifconfig eth0.3 mtu 1500
dhclient eth0.4
ifconfig eth0.4 mtu 1500
echo "nameserver 8.8.8.8" > /etc/resolv.conf
ping -M do -s 1472 -c 1 google.com
ifconfig


uname -a
Linux ubuntu 3.2.0-23-generic #36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

lspci
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)
lspci -n
02:00.0 0200: 10ec:8168 (rev 06)