Best practices for virtual machine snapshots in the VMware environment

• Snapshots are not backups. As the snapshot file is only a change log of the original virtual disk, do not rely upon it as a direct backup process. The virtual machine is running on the most current snapshot, not the original vmdk disk files.
• Snapshots are not complete copies of the original vmdk disk files. The change log in the snapshot file combines with the original disk files to make up the current state of the virtual machine. If the base disks are deleted, the snapshot files are useless.
• Snapshot files can grow to the same size as the original base disk file, which is why the provisioned storage size of a virtual machine increases by an amount equal to the original size of the virtual machine multiplied by the number of snapshots on the virtual machine.
• The maximum supported amount in a chain is 32. However, VMware recommends that you use only 2-3 snapshots in a chain.
• Use no single snapshot for more than 24-72 hours. This prevents snapshots from growing so large as to cause issues when deleting/committing them to the original virtual machine disks. Take the snapshot, make the changes to the virtual machine, and delete/commit the snapshot as soon as you have verified the proper working state of the virtual machine.

• Be especially diligent with snapshot use on high-transaction virtual machines such as email and database servers. These snapshots can very quickly grow in size, filling datastore space. Commit snapshots on these virtual machines as soon as you have verified the proper working state of the process you are testing.|
• If using a third party product that takes advantage of snapshots (such as virtual machine backup software), regularly monitor systems configured for backups to ensure that no snapshots remain active for extensive periods of time.
• Snapshots should only be present for the duration of the backup process.
• Snapshots taken by third party software (called via API) may not show up in the vCenter Snapshot Manager. Routinely check for snapshots via the command-line.
• An excessive number of snapshots in a chain or snapshots large in size may cause decreased virtual machine and host performance.
• Configure automated vCenter Server alarms to trigger when a virtual machine is running from snapshots. For more information, see Configuring VMware vCenter Server to send alarms when virtual machines are running from snapshots (1018029).
• Confirm that there are no snapshots present (via command line) before a Storage vMotion. If snapshots are present, delete them prior to the Storage vMotion. For more information, see Migrating an ESX 3.x virtual machine with snapshots in powered-off or suspended state to another datastore might cause data loss and make the virtual machine unusable (1020709).
• Confirm that there are no snapshots present (via command line) before increasing the size of any Virtual Machine virtual disk or virtual RDM. If snapshots are present, delete them prior to increasing the size of the disk/s. Increasing the size of a disk with snapshots present can lead to corruption of the snapshots and potential data loss. For more information, see Increasing the Size of a Virtual Disk.
• Reference:
• http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1025279

Configuring additional gateways for vmkernel ports on an ESXi host

To configure a second gateway for the management network:
Open a console to the ESX or ESXi host.

  Run this command:

• esxcfg-route -a target network  netmask gateway 

For example, to add a route to 192.168.100.0 network through 192.168.0.1
 run one of these command:

• esxcfg-route -a 192.168.100.0/24 192.168.0.1
• esxcfg-route -a 192.168.100.0 255.255.255.0 192.168.0.1

The command esxcfg-route -l lists the current routing table. VMware KB article

rename ESX host

To rename a VMware ESX host:
*If the ESX host is part of a Cluster, remove it from the cluster.
*If the ESX host is managed by VirtualCenter / vCenter, disconnect and remove the ESX host from the cluster.
*Make the modifications in your DNS environment to reflect the correct name and IP association for the new name.
*Log in as root to the console of ESX host.
*Using a text editor (I prefer nano ) change the name and domain name, if applicable, of the host in these files:


nano /etc/hosts
nano /etc/sysconfig/network


Execute this command where hostname is the new FQDN hostname for the ESX host:

esxcfg-advcfg -s hostname /Misc/HostName

Reboot the ESX host.
Note:
The iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the ESX host. If you change the hostname of the ESX host, make sure to review your iSCSI software initiator configuration
Join the ESX host to VirtualCenter / vCenter and clusters

reference:
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1010821

Windows 2008 R2 Best Practice Analyzer (BPA)

How to install:
BPA is installed by default on all editions of Windows Server 2008 R2 except the Server Core installation option.

How to use BPA:
You can open BPA in the Server Manager console by opening the home page for a server role that supports BPA.
To open BPA in Server Manager
1.Open Server Manager. To open Server Manager, click Start, point to Administrative Tools, and then click Server Manager.

2.In the tree pane, open Roles, and then select the role for which you want to open BPA.

3.In the details pane, open the Summary section, and then open the Best Practices Analyzer area.

ow BPA works


BPA works by measuring a role’s compliance with best practice rules in eight different categories of a role’s effectiveness, trustworthiness, and reliability. Results of measurements can be any of the three severity levels described in the following table.


*Severity level

Description
Noncompliant
Noncompliant results are returned when a role does not satisfy the conditions of a rule.

Compliant
Compliant results are returned when a role satisfies the conditions of a rule.
Warning
Warning results are returned when a role is compliant as operating currently, but may not satisfy the conditions of a rule if changes are not made to its configuration or policy settings.
Reference:
http://technet.microsoft.com/en-us/library/dd759260.aspx

Ubuntu vmware image template

these are the steps to configure a newly deploy Ubuntu VM , in my case I use a std template
1.- Remove PCI using the following command:

Sudo nano /etc/udev/rules.d/70-persistent-net.rules

2.-Re-ip the VM
Sudo nano /etc/network/interfaces

Rename host

Sudo nano /etc/hostname


sudo /etc/init.d/networking restart


Restart computer
Sudo reboot

Shavlik 8026 Problem

I'm seeing the following error on my Windows Servers with Hsavlik Netprotect installed:

Event Type: Information
Event Source: ShavlikPatchMgmt
Event Category: (8)
Event ID: 8206
Date: 9/8/2009
Time: 3:47:54 PM
User: XX\XX
Computer: XXXX
Description:
The description for Event ID ( 8206 ) in Source ( ShavlikPatchMgmt ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: \\XXX.XXX.XXX.X\C$\WINDOWS\ProPatches\Patches\, C:\WINDOWS\ProPatches\Patches\.

instructions:

1. Open a CMD prompt and navigate to C:\Windows\ProPatches\Scheduler
2. Run STSchedEx.exe /remove
3. Delete the \Propatches folder
4. Open regedit and delete: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Shavlik\Scheduler
try running the job again.

reference:
http://forum.shavlik.com/viewtopic.php?f=35&t=540&p=34323

How to install OMSA on Dell R710 with ESX 4.0

Donwload file
http://ftp.us.dell.com/sysman/OM-SrvAdmin-Dell-Web-LX-6.4.0-1266.ESX40.i386_A00.5.tar.gz
Extract Files [NOTE: This assume you have placed the .tar.gz file on the ESX host somewhere]

1.Browse to the location where you downloaded the file and unzip the package using the following command:
gunzip OM-SrvAdmin-Dell-Web-LX-6.4.0-1266.ESX40.i386_A00.5.tar.gz
2.Untar the package using the following command: tar -xvf OM-SrvAdmin-Dell-Web-LX-6.4.0-1266.ESX40.i386_A00.5.tar

Installation
1.Change current directory to the location where the files were extracted.
2.Run the following command to perform an express install:
sh linux/supportscripts/srvadmin-install.sh --express
3.Start the applicable services by running the following command:
sh linux/supportscripts/srvadmin-services.sh start

esxcfg-firewall -o 1311,tcp,in,OpenManageRequest

to access :
https://Server Name or IP:1311/

reference:
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1007617