Configuration Item Life Cycle - Virtual Servers
- Eric Puchalski
A virtual server (or "virtual machine," or "VM") is a group of files and other resources residing on one or more physical hosts and managed by a virtual machine monitor control program to appear as a stand-alone physical computer. A VM, like a physical computer, runs an operating system and applications but unlike a physical computer, a VM only has access to a specific subset of the available physical resources. The VM is defined by a set of specification and configuration files and is backed by the physical resources of a host. VMs allow a single set of physical hosts to run multiple instances of an operating system with the separate VM instances preventing applications from interfering with each other. If one application crashes, it does not affect the programs running in the other VMs.
Like a physical server, a VM can be used for a number of applications, including databases, business applications, network management, email, directory services, etc. The life cycle outlined here applies to any virtual machine irrespective of its application or underlying control program.
CI Naming Convention
Host names for virtual servers are often specified by the client at the time the VM is requested. However, when this is not the case, server names should follow the form of:
{assigned_to}-{environment}-{serviceID}nn
Where:
{assigned_to} | Identifier indicating the team, project, application, or other campus department associated with the server. |
---|---|
{environment} | Single-character identifier indicating the environment in which the server will be operating. See the Environment Classification Codes table below for a list of valid codes for this segment. |
{serviceID} | Service identifier provided by the client using the server. This is usually something meaningful to the client to help identify the purpose of the server. |
{nn} | Sequential two-digit number beginning with "00" to prevent duplication of names. |
NOTE
- When a VM is retired, the server name must be modified in the CMDB to include a prefix of RETIRED to make it obvious in listings and searches that the server is no longer being used.
- For additional information on server host naming conventions used by OIT, see: /wiki/spaces/OITEntArch/pages/14418690
Environment Classification Codes
Only the following environment classification codes may be used in a server name:
Code | Used For |
---|---|
P | Production |
N | Non-Production (AWS) |
D | Development |
Q | Quality Assurance testing |
S | Staging |
T | Testing |
Examples
The following are examples of CI names using this standard:
- mail-n-dev0 - The first general-purpose, non-production, development server for the MAIL service.
- bus-s-bar0 - The first BUS application staging server for the BAR project.
- bus-q-baz1 - The second BUS application QA server (the first ends in "0") for the BAZ project.
- RETIRED - find-p-query1 - The second query server (the first ends in "0") for the production FIND application. This server has been retired from active use.
Typical Life Cycle
CAUTION
Additions and changes to the CMDB should be made carefully and at the appropriate time. Be sure to review How to Maintain the CMDB Quality and Data Integrity before making any changes. This article explains when and how CIs are maintained and who should be maintaining them. If you have any questions about maintaining CIs then contact the ServiceNow Support Team for more information.
Phase | CI Activity |
---|---|
Phase 1: Server Requested & Approved | If ServiceNow will be used to track incidents, changes, or task assignments during the initial steps then a CI will be required. Otherwise, a CI is not required until the VM is ready to be configured. |
Phase 2: VM Configured & Tested | A Configuration Item Management Form is submitted by a member of the team supporting the VM and the new CI will be added to the CMDB by the CMDB Administration Team. The Status field should be set to Installed. Although the Status and State fields can be adjusted to indicate the actual current state of the server, the Status field is usually set to Installed throughout the configuration and testing phase. |
Phase 3: VM in Service & Maintained | Ongoing adjustments to the Status, State, and other fields in the CI record are made as needed by a member of the team supporting the VM. |
Phase 5: VM Retired | The Status and State are updated by a member of the team supporting the VM to reflect the fact that it is no longer operational and has been retired. At the same time, the name of the VM in the CI is modified to include a prefix of RETIRED to make it obvious in listings and searches that it is no longer in use. Under no circumstances should a CI ever be deleted from the CMDB. Deleting a CI record will make it impossible to trace the history of the software and any activity documented by incidents and change requests. |
Suggested Relationships
When mapping dependencies and relationships, the following are typical connections to other CI classes used by virtual servers:
Relationship | Dependent Class |
---|---|
DR provided by | Server |
Managed by | ESX Server |
Mirrored to | Mirrors |
Node of | Cluster |
Registered on | ESX Server |
Configuration Management Process
Overview
CI Life Cycles Overview
CI Naming Standards Overview
How to Maintain the CMDB Quality and Data Integrity
Resources
Committee Membership and Meetings
C/wiki/spaces/adcom/pages/68025789
OIT Architecture Review Board
Configuration Items
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