Roderick Derks

The master monitors the availability of ESXi 5 hosts and also the VM availability. The master agent also monitors all slave hosts and in case this slave host fails, all VMs on that host are restarted on another host.  Within each individual host the status of each protected VM is monitored and if a failure of that protected VMs happens, the master proceeds with the restart of this VM. The FDM master keeps a list of VMs being protected, which is updated after every power off or power on status initiated by user. FDM master keeps track of all hosts being a members of a cluster, any adding/removing of hosts refresh this list as well. When the master fails there is a re-ellection process (this was not the case in vSphere 4) and the host which has an access to the greatest number of datastores is elected as a master. Why's that? It’s because the secondary communication channel is through datastores. The next consideration is the MoID number of a host. The hosts with slave roles maintain a direct point-to-point TCP connection (no broadcasts) which is encrypted, with the Master. The election process is done via UDP, and then again only via SSL encrypted TCP the communication between the Master and the slaves are maintained.

presentation: e. sloof, text: vladan.fr d.epping r.derks

One of the great features of VMware vSphere is the capability to boot VMware ESXi from USB flash — eliminating local storage and array controllers can reduce the acquisition and operational costs for hypervisor hosts.

Now with VMware ESXi 5, it is possible to perform an automated installation to USB storage.  Simply specify usb-storage as part of the install command in an automated install script.  For example:

install --firstdisk=usb-storage --overwritevmfs

For more flexibility in a single script, multiple disk types can be specified; they will be tried in order.  Below is an example install command from a script for HP servers.  If USB flash is not installed, the on-board SAS disks will be used.  If neither are present — such as when installing virtual ESXi systems — generic local storage is the last resort.

install --firstdisk=usb-storage,hpsa,local --overwritevmfs

After some puzzeling I found the way to create a SSL web proxy that connects to SSL and non-SSL websites. This is an example of the VirtualHost configuration in the ssl.conf file.
Read more about creating ssl websites here.

NameVirtualHost *:443

<VirtualHost *:443>
    ServerName site_no_ssl.r71.nl
    SSLEngine On

    SSLCertificateFile /etc/pki/tls/certs/localhost.crt
    SSLCertificateKeyFile /etc/pki/tls/private/localhost.key

    ProxyPass / http://site_no_ssl.r71.nl/centreon/
    ProxyPassReverse / http://site_no_ssl.r71.nl/centreon/
</VirtualHost>

<VirtualHost *:443>
    ServerName other_site_no_ssl.r71.nl
    SSLEngine On

    SSLCertificateFile /etc/pki/tls/certs/localhost.crt
    SSLCertificateKeyFile /etc/pki/tls/private/localhost.key

    ProxyPass / http://other_site_no_ssl.r71.nl/
    ProxyPassReverse / http://other_site_no_ssl.r71.nl/
</VirtualHost>

<VirtualHost *:443>
    ServerName site_with_ssl.r71.nl

    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>

    SSLEngine on
    SSLProxyEngine On
    SSLCertificateFile /etc/pki/tls/certs/localhost.crt
    SSLCertificateKeyFile /etc/pki/tls/private/localhost.key

    ProxyRequests On
    ProxyPreserveHost On
    ProxyPass / https://site_with_ssl.r71.nl:443/
    ProxyPassReverse / https://site_with_ssl.r71.nl:443/
</VirtualHost>

Step 0: Install Apache module mod_ssl

# yum install mod_ssl
# service httpd restart

Step 1: Generate a Private Key

The openssl toolkit is used to generate an RSA Private Key and CSR (Certificate Signing Request). It can also be used to generate self-signed certificates which can be used for testing purposes or internal usage.

The first step is to create your RSA Private Key. This key is a 1024 bit RSA key which is encrypted using Triple-DES and stored in a PEM format so that it is readable as ASCII text.

openssl genrsa -des3 -out server.key 1024

Generating RSA private key, 1024 bit long modulus
…………………………………………………++++++
……..++++++
e is 65537 (0x10001)
Enter PEM pass phrase:
Verifying password – Enter PEM pass phrase:

Step 2: Generate a CSR (Certificate Signing Request)

Once the private key is generated a Certificate Signing Request can be generated. The CSR is then used in one of two ways. Ideally, the CSR will be sent to a Certificate Authority, such as Thawte or Verisign who will verify the identity of the requestor and issue a signed certificate. The second option is to self-sign the CSR, which will be demonstrated in the next section.

During the generation of the CSR, you will be prompted for several pieces of information. These are the X.509 attributes of the certificate. One of the prompts will be for "Common Name (e.g., YOUR name)". It is important that this field be filled in with the fully qualified domain name of the server to be protected by SSL. If the website to be protected will be https://hostname.360viewpoint.nl, then enter hostname.360viewpoint.nl at this prompt. The command to generate the CSR is as follows:

openssl req -new -key server.key -out server.csr

Country Name (2 letter code) [GB]:NL
State or Province Name (full name) [Berkshire]:NB
Locality Name (eg, city) [Newbury]:'s-Hertogenbosch
Organization Name (eg, company) [My Company Ltd]:Roderick ICT Consultancy
Organizational Unit Name (eg, section) []:Information Technology
Common Name (eg, your name or your server's hostname) []:hostname.360viewpoint.nl
Email Address []:info at 360viewpoint dot nl
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:

Step 3: Remove Passphrase from Key

One unfortunate side-effect of the pass-phrased private key is that Apache will ask for the pass-phrase each time the web server is started. Obviously this is not necessarily convenient as someone will not always be around to type in the pass-phrase, such as after a reboot or crash. mod_ssl includes the ability to use an external program in place of the built-in pass-phrase dialog, however, this is not necessarily the most secure option either. It is possible to remove the Triple-DES encryption from the key, thereby no longer needing to type in a pass-phrase. If the private key is no longer encrypted, it is critical that this file only be readable by the root user! If your system is ever compromised and a third party obtains your unencrypted private key, the corresponding certificate will need to be revoked. With that being said, use the following command to remove the pass-phrase from the key:

cp server.key server.key.org
openssl rsa -in server.key.org -out server.key

The newly created server.key file has no more passphrase in it.

-rw-r–r– 1 root root 745 Jun 29 12:19 server.csr
-rw-r–r– 1 root root 891 Jun 29 13:22 server.key
-rw-r–r– 1 root root 963 Jun 29 13:22 server.key.org

Step 4: Generating a Self-Signed Certificate

At this point you will need to generate a self-signed certificate because you either don't plan on having your certificate signed by a CA, or you wish to test your new SSL implementation while the CA is signing your certificate. This temporary certificate will generate an error in the client browser to the effect that the signing certificate authority is unknown and not trusted.

To generate a temporary certificate which is good for 365 days, issue the following command:

openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
Signature ok
subject=/C=NL/ST=NB/L='s-Hertogenbosch/O=Roderick ICT Consultancy/OU=Information
Technology/CN=hostname.360viewpoint.nl/Email=info at 360viewpoint dot nl
Getting Private key

Step 5: Installing the Private Key and Certificate

When Apache with mod_ssl is installed, it creates several directories in the Apache config directory. The location of this directory will differ depending on how Apache was compiled.

cp server.crt /etc/httpd/conf.d/ssl.crt
cp server.key /etc/httpd/conf.d/ssl.key

Step 6: Configuring SSL Enabled Virtual Hosts in the file ssl.conf

SSLEngine on
SSLCertificateFile /usr/local/apache/conf/ssl.crt/server.crt
SSLCertificateKeyFile /usr/local/apache/conf/ssl.key/server.key
SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown
CustomLog logs/ssl_request_log \
   "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"

or create a virtual host:

<VirtualHost centreon.r71.nl:443>
        ServerAdmin <info at 360viewpoint dot nl>
        DocumentRoot /usr/local/centreon/www
        ServerName hostname.360viewpoint.nl
        ErrorLog /var/log/httpd/error.log
        CustomLog /var/log/httpd/centreon.log combined

        SSLEngine  on
        SSLCertificateFile /etc/httpd/conf.d/hostname.360viewpoint.nl.crt
        SSLCertificateKeyFile /etc/httpd/conf.d/server.key
        #SSLLog /var/log/httpd/hostname.360viewpoint.nl.log
        #SSLLogLevel warn
</VirtualHost>

And you can create a proxy pass on another incoming Apache webserver which serves as a proxy:

<VirtualHost 192.168.0.11:443>
    ServerName hostname.360viewpoint.nl

    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>

    SSLEngine on
    SSLProxyEngine On
    #SSLCertificateFile /etc/apache2/ssl/certificate.crt
    #SSLCertificateKeyFile /etc/apache2/ssl/certificate.key
    SSLCertificateFile /etc/pki/tls/certs/localhost.crt
    SSLCertificateKeyFile /etc/pki/tls/private/localhost.key

    ProxyRequests Off
    ProxyPreserveHost On
    ProxyPass / https://hostname.360viewpoint.nl:443/
    ProxyPassReverse / https://hostname.360viewpoint.nl:443/
</VirtualHost>

Read more about building a single SSL proxy with multiple SSL and non-SSL websites bbehind this proxy here.

Step 7: Restart Apache and Test

/etc/init.d/httpd stop
/etc/init.d/httpd start

https://hostname.360viewpoint.nl

This article is published for my own reference. Thanks to acadia.com and JMD.

netstat -tlnp

netstat -tlnp | grep <portnumber>

Very simple procedure:

• service ndo2db stop
  service centstorage stop
  service centcore stop
• ./install.sh -u /etc/centreon
• service centstorage start
  service centcore start
  service ndo2db start

Restarting the daemons is needed to make sure the new software is loaded into memory. I.e.: not restarting the service centstorage will result in graphs not being updated anymore.

Troubleshooting Centreon Graphs

Check if service-perfdata is growing. If so then the file is not being emptied by NDO2DB:
# tail -f /usr/local/nagios/var/service-perfdata

Check if Centstorage proces is running:
# ps -ef |grep centstor

Check the centstorage log or errors:
# tail -f /usr/local/centreon/log/centstorage.log
Restart centstorage if you find errors.