Oracle vmware interview preparation

What is Oracle VM? Oracle VM is the latest virtualization technology from oracle. It is built upon the open source project Xen.Oracle VM is the virtualization solution from Oracle Corporation. Recent version on Oracle VM is Oracle VM 2.1.2.Oracle VM Server is a self-contained virtualization environment that runs various virtual machines.It is built on top of Xen Hypervisor which is a open source virtual monitoring software developed by Cambridge University Professors. Oracle VM is a Virtualization solution from Oracle. What are the components of Oracle VM? Oracle VM Server comprises of an Oracle VM Agent, a Linux Kernel.Oracle VM includes : 1) Oracle VM Server 2) Oracle VM Manager What is a Oracle VM Manager? It is a web-based GUI used to administer Oracle VM(virtual machines).It is used to perform a host of administrative tasks like virtual machine creation,dropping,managing virtual machines. What is Oracle VM Agent? Oracle VM Server communicates with Oracle VM Manager using Oracle VM Agent. What are the components that constitute Oracle VM? Oracle VM is composed of Oracle VM Server ,the software component that is used for virtualization provisioning and Oracle VM Manager a GUI tool used to control VM Server. What is an Oracle VM Agent? VM agent is a component of Oracle VM Server.It is the communication medium between the Oracle VM manager and the Oracle VM Server. What is dom0? Dom0 refers to the Domain0 which is the refernce given to Oracle VM Server. What is domu? Domu refers to unprivileged domains. What are the types of server pools? There are three major types of server pools namely Master Server,Utility Server,Virtual Servers. Give details on oracle exalogic and inherent virtualization utilization:- Oracle the 3rd biggest software and hardware giant has finally unleashed the cloud in a box. It has been rightly branded exalogic. In a recent conference larry elson Oracle CEO unleashed this interesting exalogic which has server,storage,network everything built in a box and named exalogic. Companies will find this interesting as it is going to be easy to run oracle applications in this box. In general aggregating resources and sharing it among companies form cloud computing definition. Exalogic has inherent virtualization provision that will make the resource provisioning more powerful.It is interesting to note that salesforce.com the cloud leader in market introduced vmware virtualization in its cloud platform under brand name vmforce. Exalogic is expected to take over major share of salesforce soon Give details on Oracle VM Server Utilities and Configuration Files:- A brief listing of various Oracle VM server utilities is given here: virt-install - Oracle VM Server Command-line utility used to create Virtual Machines(guests/guest operating systems). xm - Oracle VM Server Command-line tools used to manage domains. xm migrate - Oracle VM server command to migrate domains. /etc/xen/xend-config.sxp - Oracle VM Server Configuration Files.Onces changes are made to this file,we must restart the Oracle VM server for the changes to take effect. Oracle VM Server Repository - Used to store ISOs,guest and live migrations. /opt/ovs-agent-2.2 - Default Installation Location of Oracle VM Agent.Oracle VM agent is installed along with the Oracle VM Server.It doesnt need seperate installation. /opt/ovs-agent-2.2/logs/ovs_trace.log - Oracle VM Agent Installation logs. ovs-agent - Oracle VM Agent command-line tool allows us to configure and control Oracle VM Agent. service ovs-agent configure - command to configure Oracle VM Agent.This command is run as a root user What is Oracle VM(Virtualization) - xm tool? Oracle VM(Virtualization) - xm tool is the Oracle VM Server management command-line management tool that creates, destroys, manages and migrates guests. What are guests? A guest is a virtualized operating system running within a domain. A guest operating system may be paravirtualized or hardware virtualized. Multiple guests can run on the same Oracle VM Server. What is a domain? A domain is a configurable set of resources, including memory, virtual CPUs, network devices and disk devices, in which virtual machines run. A domain is granted virtual resources and can be started, stopped and rebooted independently What is a virtual machine? A virtual machine is a guest operating system and its associated application software. What are the two modes in which guest/guest os can be run? Oracle VM Server guest operating systems may run in one of two modes, paravirtualized or hardware virtualized. What is paravirtualized mode? In paravirtualized mode, the operating system guest kernel is recompiled to be made aware of the virtual environment. This allows the paravirtualized guest to run at near native speed, since most memory, disk and network accesses are optimized for maximum performance. What is hardware virtualized mode? The hardware virtualizated mode is available (either Intel VT or AMD SVM), for the guest operating system to run completely unmodified. This hardware virtualized fully-virtualized guest is carefully monitored and trapped by Oracle VM Server when any instruction is executed which would violate the isolation with other guests or dom0. What is the prerequisite for running xm command? The xm command requires xend daemon to be started. Give the syntax of xm command? xm command can be used as follows : xm [option] [argument] Give the various xm options and their usage:- console {domain-id} - Attaches to a domain's console. create [-c] {config-file [name=value ...]} - Creates a domain based on the entries in the config-file.Entering the -c parameter attaches to the domain's console when the domain is created and started.We can also enter name value pairs to override variables in the config-file using the name=value parameter. destroy {domain-id} - Immediately terminates a domain. dmesg [--clear] - Displays message buffer logs similar in format to the equivalent to the dmesg command in the Linux kernel. help [--long] [option] - Displays help on the xm command, and its options.The --long option displays full help on xm commands, grouped by function.Enter a command name as an option to the xm command to get help only on that command. info - Displays information about the host computer. list [--long --label] [domain-id, ...] - Displays information on all the running domains.The --long option displays full information on running domains.Enter the domain-id as an option to the xm command to get information on only that domain, or a set of domains. log - Displays logs similar in format to the equivalent for the Linux kernel. The log file is located at /var/log/xend.log. migrate {domain-id} {host} [-l --live] [-r=MB --resource=MB] - Migrates a domain to another computer.The domain-id parameter is the domain to migrate.The host parameter is the target computer.The --live parameter migrates the domain without shutting down the domain.The --resource parameter sets the maximum amount of Megabytes to be used. new [config-file] [option ...] [name-=value ...] - Adds a domain to Oracle VM Server domain management. pause {domain-id} - Pauses the execution of a domain. reboot [--all] [--wait] [domain-id] - Reboots a domain.The --all parameter reboots all domains.The --wait parameter waits for the domain to reboot before returning control to the console. restore {statefile} - Restores a domain from a saved state. save {domain-id} {statefile} - saves a domain state so that it can be restored at a later date. shutdown [-a] [-w] [domain-id] - Shuts down a domain gracefully.The -a parameter shuts down all domains.The -w parameter waits for the domain to shut down before returning control to the console. top - Displays real time monitoring information of the host and domains. unpause {domain-id} - unpauses a paused domain. Give details on xm new option:- new [config-file] [option ...] [name-= value ...] Adds a domain to Oracle VM Server domain management. We can set domain creation parameters with a number of command-line options, a Python script (with the --defconfig parameter), or an SXP configuration file (the --config parameter). We can set configuration variables with name=value pairs, for example vmid=3 sets vmid to 3. The config-file parameter is the location of the domain configuration file. The option parameter is one or more of the following: [-h --help] Displays help on the command. [--help-config] Prints the available configuration variables for the configuration script. [-q --quiet] Quiet. [--path=path] Searches the location given in path for configuration scripts. The value of path is a colon-separated directory list. [-f=file --defconfig=file] Uses the given Python configuration script. The script is loaded after arguments have been processed. Each command-line option sets a configuration variable named after its long option name, and these variables are placed in the environment of the script before it is loaded. Variables for options that may be repeated have list values. Other variables can be set using name=value on the command-line. After the script is loaded, values that were not set on the command-line are replaced by the values set in the script. [-F=file --config=file] Sets the domain configuration to use SXP. SXP is the underlying configuration format used by Xen. SXP configurations can be hand-written or generated from Python configuration scripts, using the --dryrun option to print the configuration. [-n --dryrun] Prints the resulting configuration in SXP, but does not create the domain. [-x --xmldryrun] Prints the resulting configuration in XML, but does not create the domain. [-s --skipdtd] Skips DTD checking and XML checks before domain creation. This option is experimental and may slow down the creation of domains. [-p --paused] Leaves the domain paused after it is created. [-c --console_autoconnect] Connects to the console after the domain is created. Usage Example : xm new /home/myhome/myconfig