Creating Centos-7 Image for Openstack

Download the Centos-7 Minimal ISO from the centos ISO repo

http://isoredirect.centos.org/centos/7/isos/x86_64/

Setting up the KVM environment to create the custom images.

yum install kvm qemu-kvm python-virtinst libvirt libvirt-python virt-manager libguestfs-tools

Script for starting the KVM installation  cat createcentos7.sh
=============
IMAGE=Centos7.qcow2
VIRTIO_ISO=/root/virtio-win-0.1-81.iso
ISO=/ISO/CentOS-7.0-1406-x86_64-Minimal.iso

KVM=/usr/libexec/qemu-kvm
if [ ! -f "$KVM" ]; then
    KVM=/usr/bin/kvm
fi

qemu-img create -f qcow2 -o preallocation=metadata $IMAGE 8G

$KVM -m 2048 -smp 2 -cdrom $ISO -drive file=$VIRTIO_ISO,index=3,media=cdrom  -drive file=$IMAGE,if=virtio,boot=off -boot d -vga std -k en-us -vnc 192.168.2.10:4 -usbdevice tablet
=============
using any VNC client connect to 192.168.2.10:4  and do the rest of configuration.

Complete the installation do the following configurations after starting the image in openstack


cat <<EOF >/etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE="eth0"
BOOTPROTO="dhcp"
ONBOOT="yes"
TYPE="Ethernet"
PERSISTENT_DHCLIENT=1
EOF

cat <<EOF > /etc/sysconfig/network
NETWORKING=yes
NOZEROCONF=yes
EOF
yum update -y

yum -y install https://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-2.noarch.rpm -y

yum install cloud-init

yum history new
yum clean all
truncate -c -s 0 /var/log/yum.log
rm -rf /var/lib/yum/*
rm -rf /var/lib/random-seed
rm -rf /root/install.log
rm -rf /root/install.log.syslog
rm -rf /root/anaconda-ks.cfg
rm -rf /var/log/anaconda*


Now save the Vm as a snapshot and use it again :)

List installed Python Modules.

First install the python-pip package and use "pip freeze" command to display the Modules.

[root@ceph01-server ~]# python --version
Python 2.6.6
[root@ceph01-server ~]# pip freeze
Cheetah==2.4.1
Markdown==2.0.1
PyYAML==3.10
Pygments==1.1.1
argparse==1.2.1
backports.ssl-match-hostname==3.4.0.2
boto==2.32.1
ceph-deploy==1.5.17
chardet==2.0.1
cloud-init==0.7.4
configobj==4.6.0
distribute==0.7.3
heat-cfntools==1.2.6
iniparse==0.3.1
jsonpatch==1.2
jsonpointer==1.0
ordereddict==1.1
policycoreutils-default-encoding==0.1
prettytable==0.7.2
psutil==0.6.1
pycurl==7.19.0
pygpgme==0.1
requests==1.1.0
setools==1.0
six==1.7.3
urlgrabber==3.9.1
urllib3==1.5
yum-metadata-parser==1.1.2
[root@ceph01-server ~]#

Resuming Download in Linux

wget -c Resume Unfinished Downloads

This small command can save your time and money while downloading big files so I found it useful to share with you .I was downloading a file with wget command and it was 98% downloaded and my computer turned off unexpectedly. It was a very huge file and downloading it from the beginning was a painful job. So I came  across a wget command that can be used for resuming unfinished downloads.

I found this command after reading wget manual, you can add wget -c or wget --continue to resume unfinished download.

wget -c url

Webmaster Tools errot "Warning: Missing required field "updated"" with Google Blogger

When you check your blog hosted with Blogger for Google Authorship with Rich snippet testing tool mostly you get two common warning and error messages 'Warning: Missing required field "updated".' and 'Warning: Missing required hCard "author".

Warning: Missing required field "updated"

Note: Before making any changes to the template please take the backup. Link given below will help you.

Go to Blogger Dashboard › Select Blog › Click on Template › Proceed › Edit HTML

Now press Ctrl+F to find the code timestamp-link   or  published   like below

<a class='timestamp-link' expr:href='data:post.url' rel='bookmark' title='permanent link'><abbr class='published' expr:title='data:post.timestampISO8601'><data:post.timestamp/></abbr></a>

Now care fully change it to the code below

<a class='timestamp-link' expr:href='data:post.url' rel='bookmark' title='permanent link'><abbr class='updated published' expr:title='data:post.timestampISO8601'><data:post.timestamp/></abbr></a>

Now have a smile!


You can re check this here Rich Snippet testing tool.

Delete a VM in an Error State in Openstack

Delete a VM in an Error State

mysql -u$MYSQL_USER -p$MYSQL_PASSWD -h$MYSQL_HOST -e 'USE nova; DELETE FROM security_group_instance_association WHERE instance_id IN (SELECT id FROM instances WHERE vm_state = "error");'
mysql -u$MYSQL_USER -p$MYSQL_PASSWD -h$MYSQL_HOST -e 'USE nova; DELETE FROM block_device_mapping WHERE instance_id IN (SELECT id FROM instances WHERE vm_state = "error");'
mysql -u$MYSQL_USER -p$MYSQL_PASSWD -h$MYSQL_HOST -e 'USE nova; DELETE FROM instance_info_caches WHERE instance_id IN (SELECT uuid FROM instances WHERE vm_state = "error");'
mysql -u$MYSQL_USER -p$MYSQL_PASSWD -h$MYSQL_HOST -e 'USE nova; UPDATE fixed_ips SET allocated = 0 WHERE instance_id IN (SELECT id FROM instances WHERE vm_state = "error");'
mysql -u$MYSQL_USER -p$MYSQL_PASSWD -h$MYSQL_HOST -e 'USE nova; DELETE FROM instances WHERE vm_state = "error";'

Resetting the Instance state once it’s in a stuck state in Openstack

Resetting the Instance state once it’s in a stuck state

$ nova list
+--------------------------------------+----------------+---------+------------------------------------------.  -------------+-------------+----------------------------------+
| ID                                                                 | Name         | Status        |   Task State  | Power State | Networks                                      |
+--------------------------------------+----------------+---------+-------------------------------------------  -------------+-------------+----------------------------------+
| ca9496e9-0bd2-4734-9cf9-eb4e264628f7 | www            | SHUTOFF | powering-on | Shutdown    | fsf-lan=10.0.3.18, 93.20.168.177  |
+--------------------------------------+----------------+---------+----------------------------------------------------------+-------------+----------------------------------+

   
Setting the fields for the instance directly in the database will allow operations on the instance (nova start or nova volume-detach for instance):

$ mysql -e "update instances set task_state = NULL, \
           vm_state = 'stopped', \
           power_state = 4 \
           where deleted = 0 and hostname = 'www' and \
           uuid = 'ca9496e9-0bd2-4734-9cf9-eb4e264628f7'" nova

Removing a Cinder volume from the MYSQL in Openstack

Get the Cinder Volume’s ID from Cinder List and use it in other commands

>>cinder list;
$> nova volume-detach testvm aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee
$> cinder delete vol-00000001
Or
In mysql Server
mysql
use cidner;
SELECT id,status,attach_status,mountpoint,instance_uuid from volumes;
UPDATE volumes SET status="available", attach_status="detached", mountpoint=NULL, instance_uuid=NULL WHERE id="57b32eaf-7b71-49bf-a8fd-4115567a6cda";
SELECT id,status,attach_status,mountpoint,instance_uuid from volumes;
bye