To fix the error of Double.MIN_NORMAL not defined, replace it with
Double.longBitsToDouble(0x0010000000000000L)
Double.MIN_NORMAL is a constant holding the smallest positive normal value of type double, 2-1022.
Without any additional comments, we managed to install KVM over a fresh installation of Ubuntu 11.10 (Oneiric Ocelot).
To do this we installed the following packages from the repositories and added our user to the libvirtd group.
We called kvm-ok to make sure that our hardware supports KVM properly and thus having better performance.
Installation Commands:
sudo apt-get install kvm libvirt-bin sudo adduser $USER libvirtd sudo apt-get install virt-viewer sudo apt-get install python-vm-builder sudo apt-get install bridge-utils sudo apt-get install virtinst #for cloning
After these we created a virtual machine with the following command:
sudo vmbuilder kvm ubuntu --suite oneiric --flavour virtual --arch amd64 --mem 1024 --cpus 2 -o --libvirt qemu:///system --ip 192.168.0.100 --hostname uranus --part vmbuilder.partition --user userName --name MyName MySurname --pass myPassword --addpkg unattended-upgrades --addpkg acpid --addpkg nano
where in general, what it does is, create an Ubuntu Oneiric Ocelot JeOS virtual machine that has an AMD64 architecture, 1GB of RAM, 2 Virtual CPUs, it’s name is uranus, has a user with the username userName, has pre-installed some applications like nano and enabled automatic updates for the system.
If you are trying to check if a socket is empty but you cannot use select(), because what you need is to check the write buffers instead of the read ones just to be sure that you have successfully managed to send all data to your peers before terminating, or if you want to tell if a socket buffer is full.
You can use the ioctl to find out.
To check a write buffer if it empty (assuming you have already put data there and want to check if they were consumed):
ioctl(fd, SIOCOUTQ, &pending);
Where fd is the socket’s file descriptor and pending the variable were the remaining size of data will be returned.
To check a read buffer if it empty (assuming someone has already put data there and you want to check if they there is any without consuming them):
ioctl(fd, SIOCINQ, &pending); *note the difference on the second parameter, where we change the flag from SIOCOUTQ to SIOCINQ
Among other includes be sure to add these:
#include <sys/ioctl.h> #include <linux/sockios.h>
So you’ve set up KVM on your machine and you have installed a few guests to run on top, now it’s the time to access them.
Since KVM can run without a GUI, you might want to control these guests from the command line. But, how can you do it if you do not know the IP of the guests?
You can either connect to the guest using virt-viewer:
virt-viewer -c qemu:///system $MACHINE &
which requires more bandwidth since it will open up a VNC session.
Or, use ssh to connect using the guest’s name, like this:
ssh $MACHINE
which doesn’t require that you know the IP beforehand.
To achieve this, access guest machines using their hostname only, you can do the following: Edit /etc/resolv.conf and add the line nameserver 192.168.122.1 right after the search entries .
Your file should look something like this afterwards:
domain in.bytefreaks.net
search in.bytefreaks.net
nameserver 192.168.122.1
nameserver 194.44.13.20
nameserver 194.44.13.58
nameserver 194.44.13.11
Then you are ready to go! No restarts needed no extra steps.
NOTES:
