Ciao Sic

October 24th, 2011


EC2 tty configuration

March 18th, 2011

Hi, if on your CentOS instance you can see some of this lines in your /var/log/messages

... /sbin/mingetty[1816]: tty2: No such file or directory
... /sbin/mingetty[1817]: tty3: No such file or directory
... /sbin/mingetty[1818]: tty4: No such file or directory
... /sbin/mingetty[1819]: tty5: No such file or directory
... /sbin/mingetty[1820]: tty6: No such file or directory

edit /etc/inittab and comment the relative lines

# Run gettys in standard runlevels
1:2345:respawn:/sbin/mingetty tty1
#2:2345:respawn:/sbin/mingetty tty2
#3:2345:respawn:/sbin/mingetty tty3
#4:2345:respawn:/sbin/mingetty tty4
#5:2345:respawn:/sbin/mingetty tty5
#6:2345:respawn:/sbin/mingetty tty6

save it and then use the following command

kill -HUP 1

That’s all!


How to convert instance-store to EBS for boot

December 7th, 2010

In the last days I spent some time to take care of some AWS instances, and I ported one of this from instance-store to EBS, so the whole server is persistent and can be restarted without any data loosing.

  • Start ad instance-store machine, modify as you like.
  • Create a Volume with the size of 10GB and attach it to instance (suppose that it will be /dev/sdf).
  • format it as EXT3
    mkfs.ext3 /dev/sdf
  • mount it

    mkdir /mnt/ebs
    mount /dev/sdf /mnt/ebs
  • sync the instance with the volume

    rsync -avHx / /mnt/ebs
    rsync -avHx /dev /mnt/ebs
  • flush and umount

    umount /mnt/ebs
  • detach the volume and create a snapshot
  • register the AMI

    ec2-register --region $REGION -s $SNAP –name $NAME –description “$DESC” –architecture $ARCH --root-device-name /dev/sda1 --block-device-mapping '/dev/sda2=ephemeral0' --block-device-mapping '/dev/sda3=ephemeral1'

    change the appropriate parameter with your own

Now you have a fresh EBS AMI ready to boot into a new instance.


Missing modules.dep on EC2 Instance

October 22nd, 2010

If you are experiencing the following error in your /var/log/messages

... ... modprobe: FATAL: Could not load /lib/modules/2.6.16-xenU/modules.dep: No such file or directory

download, extract into / and the exec

$ depmod -a


Upgrading to Kubuntu 10.10 Alpha 3

September 2nd, 2010

yesterday I’ve upgraded my notebook to the development version of Kubuntu, there was only 2 problems. The first is that my “sudo update-manager -d” does not work properly, I got a dependency break that I resolved reading the relative Launchpad bug. Another problem was a post upgrade problem, the nvidia driver (ver. 256.44) was not loaded and for resolve it I just added the following lines to my generated (with nvidia-xconfig) xorg.conf

Section "ServerFlags"
Option "IgnoreABI" "True"

Now everything seems to work well! :)


Creating software RAID on living CentOS

May 17th, 2010

I need to add a software RAID 1 to our development server. Actually it is a used server so I cannot do it during installation phase. After searching a bit into the web I found a very nice guide here.


New web vocalization service

February 22nd, 2010

In the last months we released under our brand name the web vocalization service. This service is able to read your site only adding a link/form on your pages. In the next days you can find on our site the various pricing, initially only three version will be available: Free (with advertising), Basic and Plus.
We have in development some platforms integration too, for now WordPress (soon available on this blog obviously) and Drupal, in the next months some other platforms will be take in care (if you need some specific platform integration does not hesitate to ask).

Let me to know your feedback.


Increase disk size of Xen VM

November 21st, 2009

Looking for a fast and safe mode to increase the size of a Xen VM I find this link that match exactly my situation: a image disk with only two partitions, the root partition and a swap partition.

So this is the steps that I followed to reach my goal:

  1. create a backup of the diskimage that you want to modify
  2. shutdown domU
  3. add extra space to the image by entering: dd if=/dev/zero bs=1M count=1024 >> /path/to/diskimage (this would add another 1024M to the DomU image)
  4. boot domU
  5. disable swap partitions by entering: swapoff /dev/xvda2 (or what corresponds to your setup)
  6. fdisk /dev/xvda (or what corresponds to your setup)
  7. press p + enter so see the whole disksetup
  8. delete the second swap partition by entering d + enter and then 2 + enter
  9. delete the system partion by entering d + enter and then 1+enter
  10. recreate the system partition with the same start cylinder than the older one but an end-cylinder bigger than the old cylinder value. press n <enter> p <enter> 1 <enter> and then enter the values
  11. recreate the swap partition (with n <enter> p <enter> 2 <enter> and appropriate values
  12. chance the partition type of partition 2 to swap by pressing: t <enter> 2 <enter> 82 <enter>
  13. exit fdisk by pressing w <enter>
  14. execute: mkswap /dev/xvda2 to make the swap space ready
  15. reboot domU
  16. execute: resize2fs /dev/xvda1

Be aware that if you have a different partition schema this would not work!


Force time to a AWS Instance

November 20th, 2009

echo 1 > /proc/sys/xen/independent_wallclock

Now you can force the host date.


How To create a CentOS 5.3 EC2 AMI

October 25th, 2009


after looking some usefull guides to create Amazon Machine Image based on CentOS distribution, I decide to write the steps that i followed.

First of all we need of a CentOS machine, if you don’t have it use a virtual machine program (on my Kubuntu based laptop I use VirtualBox), once we have it login and start:

  • create image file (in this case about 1,1GB of space reserved), take in mind that this will be the size of your / mountpoint on AWS, so if you want to use the whole size use 10GB (count=10240)

    dd if=/dev/zero of=base-server.fs bs=1M count=1024
  • then create the file system

    mke2fs -F -j base-server.fs
  • create a mount point and mount the image file

    mkdir /mnt/ec2-fs
    mount -o loop base-server.fs /mnt/ec2-fs
  • prepare a base filesystem structure

    mkdir /mnt/ec2-fs/dev
    /sbin/MAKEDEV -d /mnt/ec2-fs/dev/ -x console
    /sbin/MAKEDEV -d /mnt/ec2-fs/dev/ -x null
    /sbin/MAKEDEV -d /mnt/ec2-fs/dev/ -x zero
    mkdir /mnt/ec2-fs/etc
    mkdir /mnt/ec2-fs/proc
    mount -t proc none /mnt/ec2-fs/proc
  • create a yum-xen.conf file with the repository info (in this case for i386 32bit architecture)

    name=CentOS-5.3 – Base
    #released updates
    name=CentOS-5.3 – Updates
    #packages used/produced in the build but not released
    name=CentOS-5.3 – Addons
    name=CentOS 5.3 Extras $releasever – $basearch
  • install all packages in “Core” group (optionally use “Base” or whatever you want)

    yum -c yum-xen.conf --installroot=/mnt/ec2-fs -y groupinstall Core
  • edit network interface configuration file /mnt/ec2-fs/etc/sysconfig/network-scripts/ifcfg-eth0

  • turn on networking editing file /mnt/ec2-fs/etc/sysconfig/network

  • create the file /mnt/ec2-fs/etc/hosts and add at least the localhost interface

    echo " localhost.localdomain localhost" > /mnt/ec2-fs/etc/hosts
  • copy your resolv.conf, when boot from AWS DHCP was changed

    cp /etc/resolv.conf /mnt/ec2-fs/etc/resolv.conf
  • edit the file /mnt/ec2-fs/etc/fstab (32 bit linux machine match only m1.small and c1.medium instance with this mount points)

    /dev/sda1 / ext3 defaults 1 1
    none /dev/pts devpts gid=5,mode=620 0 0
    none /dev/shm tmpfs defaults 0 0
    none /proc proc defaults 0 0
    none /sys sysfs defaults 0 0
    /dev/sda2 /mnt ext3 defaults 0 0
    /dev/sda3 swap swap defaults 0 0
  • if you need more packages install now with yum

    yum -c yum-xen.conf --installroot=/mnt/ec2-fs -y install wget
    yum -c yum-xen.conf --installroot=/mnt/ec2-fs -y install curl
  • disable selinux in /mnt/ec2-fs/etc/selinux/config by setting SELINUX=disabled
  • move TLS library out of the way (if you have it)

    mv /mnt/ec2-fs/lib/tls /mnt/ec2-fs/lib/tls.disabled
  • put your ssh public key for root user (if you want to use another user, create it) in /mnt/ec2-fs/root/.ssh/authorized_keys or read the following step if you prefer to use the AWS assigned key-pair
  • create the file /mnt/ec2-fs/usr/local/sbin/ (have you installed curl? is needed for this script)

    if [ ! -d /root/.ssh ] ;
    then mkdir -p /root/.ssh
    chmod 700 /root/.ssh
    # Fetch public key using HTTP
    curl -f > /tmp/my-key
    if [ $? -eq 0 ] ;
    cat /tmp/my-key >> /root/.ssh/authorized_keys
    chmod 600 /root/.ssh/authorized_keys
    rm -f /tmp/my-key

    make it executable

    chmod +x /mnt/ec2-fs/usr/local/sbin/

    add it to /mnt/ec2-fs/etc/rc.local

    # get AWS credentials
  • chroot into your image

    chroot /mnt/ec2-fs /bin/bash
  • start your services at desired run level and emtpy yum cache

    chkconfig --level 345 sshd on
    yum clean all

    then exit from chroot

  • umount image file

    umount /mnt/ec2-fs/proc
    umount -d /mnt/ec2-fs

Now your image file is ready, simply create bundle volume and upload to S3

  • install ruby, download ec2-ami-tools and install it

    yum install ruby
    rpm -Uvh ec2-ami-tools.noarch.rpm
  • create bundle volume (put file in /tmp)

    ec2-bundle-image -i base-server.fs -c my-cert.pem -k my-private-key.pem -u 1234-5678-9101 (amazon account id)
  • upload to Amazon S3

    ec2-upload-bundle -b base-server -m /tmp/base-server.fs.manifest.xml -a my-aws-access-key-id -s my-secret-key-id

Now you can register an AMI and launch your instance.