ESX and ESXi : The differences and the limitations

ESXi
1. Free. No license required.
2. Extremely small footprint (32MB on memory), Fast boot up.
3. Do not have service console.
4. Actually running on a newer architecture than ESX
5. Future development will focus on ESXi.
6. Users are encouraged to deploy ESXi.
7. VCenter cannot manage free ESXi without a vSphere license as its APIs only grant read-only access.


ESX
1. vSphere license required.
2. Bigger size compared with ESXi. 2GB.
3. Has service console. Automated scripts supported.
4. works with VCenter depending on the license purchased.





Read more :
How does VMware ESXi Server compare to ESX Server?
ESXi vs. ESX: A comparison of features

Netbackup 7 Launching : De-dupe and Virtualization Backup

Symantec launched its Version 7.0 Netbackup at Nikko Hotel today.

Netbackup 7.0 key points:



1. De-dupe
Netbackup 7.0 focus on the idea of de-duplication everywhere. Using de-dupe to significantly cut down the volume to be actually backup/stored. At the same time reduce the resource utilized, e.g. reduced Network traffic, reduced WAN traffic for DR site replication, reduced storage space, reduced backup time.

Of course with de-dupe introduced, some CPU and RAM overhead needs to be accounted for, and it depends on where you decided to actually run the de-dupe algorithm.

a. De-dupe appliances - Data sent from client to media server then onto a de-dupe device to actually do the de-dupe algorithm. Resource is only saved at the final stage when "Unique Data" is written onto storage.

b. Media Server - Data sent from Client to media server and then do a de-dupe at the Media server. Then "Unique data" is written onto storage. Savings is between the media server and the final storage.

c. Client side - Data is de-dupe at client side before heading out to the Media server. Network utilization reduced, Storage required for backup is reduced, backup window is reduced, but some overhead at the CPU and RAM over at client side needs to be sized in.



2. Virtualization Backup.
Apparently Netbackup 7.0 is able to do virtualization backup more efficiently than other competitors. Reason being Netbackup 7.0 only needs to backup once on the vmdk to be able to do both "Whole VM" restoration and "Single File" restoration, whereas other vendors needs to do 2 backups to accomplished that.

A new term "Change Block Tracking" is also mentioned during the briefing. Went to this blog and got some idea about CBT. (Seriously good info for Virtualization and Cloud)

CBT seems to be a new features for Vsphere 4.0 kernel. Instead of writing own code to pull block info from the vsphere kernel, CBT allows the 3rd party apps to query the info directly from the kernel and the result is better efficiency.

It is also used in VSphere 4.0 VMotion where it works like a buffer area to keep track of all the I/O while Vmotion is copying the initial copy of the data files. After initial copy of data files are complete, the CBT will be traced to write the changes into the initial copy. Where at the same time new I/O are traced continuously.

The algorithm goes on until the changes are really small and the copy can be done instantly. The VM will then be suspend/resume (instantly) after the final traces are done. This I guess gives even seamless Vmotion.

Cloud Computing : The next gen of computing industries infrastructure.

Cloud Computing has been around since 2007 and it's becoming more and more of a hot topic, just like how virtualization has infiltrated the industry. Exactly what is Cloud Computing?

From my understanding, Cloud Computing is an initiative, the idea to change the currently "Device Metric" computing infrastructure, into a "User, App, Service Metric" infrastructure.

In current industry, when a new service / application is required by the organization, a normal workflow which includes quotation for hardwares and apps, the design of network layout, security metrics, backup design, Disaster Recovery design and High Availability design. All and all, the project is still driven by devices, where each project will actually have their own hardwares / devices.

With the introduction of virtualization, industry is starting to change whereas hardwares are utilized more efficiently, and it offers scalability and flexibility for apps and services. At the same time, DR and HA options has become an easier approach with the help of virtualization. The segregation of "Devices" is becoming ambiguous.

With Cloud Computing, the idea is to run the IT in the organisation as a service provider. By using virtualization, the whole underlying hardwares can be seen as a giant pool of resources which provides flexibility and high availability. Apps and services can be provisioned for new requirements as soon as the approval is completed by the Managers. The workflow to acquire a quotation and table the pricing to the users is no longer required, instead, a chargeback system is used to calculate the amount of resources the users are using. (e.g. storage, CPU, backup, etc)

The giant resource pool, this is what we call a "Cloud".

Cloud can also be ran externally, where apps and services are hosted on vendors premises. Organisation can still have their own management and control over the apps and services as if the machines resides in their own premises. The main advantage of this is the provision and expansion of your organisation services to strategic locations, without having to setup a new premises with its own hardwares, much like how global services (google, facebook, msn..) works.

This is what we call a "Public Cloud"




VMware Cloud Computing
Private Cloud Computing intro
Cool demonstration on how automation and virtualization helps to provide a consistent level of service
VMware president and CEO, Paul Maritz, talks about the Cloud and VCloud initiative
VCloud Blog


I believe the biggest challenge for IT managers going forward to Cloud computing is the justification for the initial setup and the cost of restructuring the IT organisation.

How to remove data in Active Directory after an unsuccessful domain controller demotion

http://support.microsoft.com/kb/216498

Exchange 2003 : System Attendant Service could not be started. DSAccess - Topology Discovery Failed.

Early this morning I received a critical call where the Exchange 2003 Server has went down. Went on site and discovered that the server could not be brought up due to System Attendant service hung during startup.

1. Exchange Server could not be boot into Normal Mode with Exchange System Attendant service enabled.

2. Boot into Safe Mode and disable Exchange System Attendant and Exchange Information Store Service. Reboot and able to boot into Normal Mode.

3. Attempts to start Exchange System Attendant failed. Service could not be started as normal.

4. Event logs > Application logs showing multiple entries of the below errors.

Event Type: Error
Event Source: MSExchangeDSAccess
Event Category: Topology
Event ID: 2114
Date: 10/06/2010
Time: 1:01:14 PM
User: N/A
Computer: MYKLX001
Description:
Process MAD.EXE (PID=4788). Topology Discovery failed, error 0x80040920.

For more information, click http://www.microsoft.com/contentredirect.asp.



Event Type: Error
Event Source: MSExchangeFBPublish
Event Category: General
Event ID: 8213
Date: 10/06/2010
Time: 1:01:14 PM
User: N/A
Computer: MYKLX001
Description:
System Attendant Service failed to create session for virtual machine MYKLX001. The error number is 0xc10306ce.

For more information, click http://www.microsoft.com/contentredirect.asp.




We tried to source solution from the internet. The most direct answer from Google is the below KB.

Exchange services do not start, and event IDs 2114 and 2112 are logged in the Application log in Exchange Server 2003 or in Exchange 2000 Server

This KB assumes that the problem lies with the security access of the Exchange Enterprise Servers Group. Hence the verification on the Default Domain Policy, Default Domain Controller Policy and the User Rights Assignment, and the DomainPrep and so on.

However, we verified the above and even ran the DomainPrep, the problem is still not solved. System Attendant still fails due to Topology Discovery Failure.

**Time is running short as the managers need the emails to be up a.s.a.p**


Without a clue, we were forced to consult Microsoft PSS.
Within 10 minutes, Microsoft engineer discovered the source of the problem.


Within the Exchange Server Netlogon Service Registry lies a Key that record the value of the AD site to be contacted when System Attendant tries to pull data.


HKLM\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters

Key:
DynamicSiteName (REG_SZ) : SITENAME
SiteName (REG_SZ) : SITENAME






2 Days ago, the AD site name was reconfigured. The Exchange Server Netlogon however do not get updated with the new configuration. Hence the System Attendant could not communicate with AD anymore.

As explained by Microsoft, the System Attendant will only encounter problem when the service was restarted and tries to pull data from AD.

New installation of Exchange will automatically configure this registry key. However, when a site name is changed, administrators should verify this Key at the Exchange Server themselves because the Netlogon will not get updated.

As indicated by the engineer,
** This is not documented in any KB articles **


So as soon as we changed the registry to reflect the new site name, System Attendant started and Information Store can be brought up. Email service back online.


So, the next time you wanna reconfigure your AD site, do take note whether the site host any exchange server, and whether the Exchange Server Netlogon Registry Key has been updated with the change.

Vmware licensing : VSphere 4.0 and VCenter 4.0

Purchase option

Comparison of different editions

Pricing and packages whitepaper

Robocopy : migrate files, copy file attributes, ACLs, empty folders...

Robust File and Folders copy (Robocopy)
By default Robocopy will only copy a file if the source and destination have different time stamps or different file sizes.

Robocopy

Some of the useful swtiches:

robocopy \\server01\folder01 \\server02\folder02 /e /copyall

Copy everything under folder01 to folder02 (includes all files attributes, security settings, time stamp), empty folders included.


robocopy \\server01\folder01 \\server02\folder02 /s /copyall

Copy everything under folder01 to folder02 (includes all files attributes, security settings, time stamp), empty folders not included.


robocopy \\server01\folder01 \\server02\folder02 /e /copyall /create

Create folders and files structure for everything under folder01 at folder02 (includes all files attributes, security settings, time stamp), empty folders included. Good for testing folders migration.


robocopy \\server01\folder01 \\server02\folder02 /e /copyall /move

Move everything under folder01 to folder02 (includes all files attributes, security settings, time stamp), empty folders included.