Showing posts from September, 2010

Active Directory : Schema

What is Schema?
Schema is a collection of Objects , Object classes and their attributes. If you see in the image above “Administrator” is a user object in Active Directory, and the properties of that user object are called as Attributes. Here Remote control is an attribute, COM+ is an attribute. Further every attribute again has more attributes like Dial-in attribute has Allow Access, Deny Access and so on.... This is called as “Schema”.

Where this Schema information Stored?
It is stored in NTDS.DIT(DIT stands for Data Information Tree) file. NTDS.DIT is main db file for Active Directory and this data will be divided into 3 partitions namely Domain Partition, Configuration Partition and Schema Partition.
These partitions can be visually seen using REPLMON (a deprecated GUI tool from windows 2003 resource kit)

       image from google images

Schema partition - Defines rules for object creation and modification for all objects in the forest. Replicated to all domain controllers in the forest.…

vSphere PowerCLI : Part - II

Now that you guys have installed PowerCLI and you have got an idea how to start use PowerCLI, today we would look at some PowerCLI commands which would be use full in day-to-day administration.To connect to your ESX/I or VC system use the below command:
PS> Connect-VIServer <IP for ESX/I or VC> or <DNSNAME for ESX/I or VC>
EG --> Connect-VIServer
EG --> Connect-VIServer esx01
EG --> Connect-VIServer VC01
Once this is enter, a window will pop up for login credentials. If you are connecting to your ESX or ESXi system authenticate with root user. If you are connecting to your VC authenticate with the user which has admin access to the VC.Now that you are able to connect the your host / VC using PowerCLI, lets have a look at some useful commands for the ESX adminstration..To list all the VMware Infrastructure Servers (VMHost) on the connected VI Server
Get-VMHostGet all Hosts member of a Cluster
Get-Cluster Cluster01 | Get-VmHostTo add a new VMHost to in…

VMware Interview Questions - Part II

Hi Friends, So many of you already read the Part - 1 post of VMware Interview Questions, if not please access this link of all thank you so much for your support in my blog. With this energy, i gathered some more interview questions, and posting them in this latest article. Please read those questions from the following link. I am uploading it to Google docs, because everybody can read it everywhere.NOTE : I don't know answers to some of the questions in the doc, so if anyone of you aware of the answer for any particular question, please send me an email with the question and answer. I will update it in the doc. (This is what we call it as KNOWLEDGE SHARING)Email : charan@isupportyou.netVMware Interview Questions - Part II DocPlease let me know, if you facing any difficulties in accessing the doc.Please subscribe now, email me if you have any questions.keep Visiting :).Related PostsVMware Interview Questions -…

VMware Storage : NFS Datastore's

Hi Guys,Today I want to share a real time concept from Mr.Terence, who has mailed me this concept. I am pasting the matter as it is...<----Hi
Just thought I'd share a working solution. I've recently begun using a "cheap" solution for centralized VM storage : Windows Server 2003, with NFS service.Basic benefits for ESX environment:
- central datastore for VM's, so if an ESX host dies, we've been successfully able to boot up VM's from other ESX hosts very quickly
- Windows Server is simple to backup : backing up our VM's at VMDK level works great (using BackupExec 12 with open-file backup enabled)
- no expensive dedicated storage hardware needed; although we are lucky to have 10K RPM disks in our Windows Server, so throughput has been fantastic
- Windows Server is much simpler to install & manage than some SAN / NAS environments; and the server can be used for other services if needed (DHCP, DNS, File Server, Print Server, app server, etc)---->Do …

vSphere PowerCLI : Part - I

Before running PowerCLI, you will have to run the below PowerShell command to change the default execution policy to trust scripts which aren't digitally signed. To do so:
- Start the windows powershell by clicking on the icon on your desktop.
- Once the powershell window is open type --> "Set-ExecutionPolicy - ExecutionPolicy Unrestricted" and then exit. Now PowerCLI can be started by clicking on the icon on your desktop to have the below window. I'll continue the article in part 2 in next weekend!.... till that time enjoy this short getting started for PowerCLI. If you need any help or have any suggestions / comments, please use the comments panel below. I'll try my best to answer at the earliest and with utmost accuracy. :)Thanks for coming to my blog. Please subscribe now. Next____________________________________________________________________________ This article has been posted by Mr.Amit. He was acting as co-author for this blog. He is a VMwar…

Windows Desktop Support Interview Questions.....

Hi Firneds,

Today i am posting some of the Desktop Support Interview Questions which i gathered on the Internet, these may be helpful to you.  I have uploaded the doc to the google docs, you can simply access the doc or you can download it by clicking on the below link.

Desktop Support Interview Questions

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Windows Related Posts
· Some Windows Active Directory Interview Questions..
· Applying SQL Server SP3 Failed, How to fix it?
· How to fix Remote Desktop Connection Problems in Windows Server 2008?
· How to RENAME a Windows 2003 Domain ?
· How to reset TCP/IP in Windows or How to delete TCP/IP entries from Registry ?
· What is Clustering? How it works?
· Understanding DNS : Domain Naming Server
· DHCP : Dynamic Host Configuration Protocol
· Active Directory : Behind the Directory
· How to join a computer to the domain which is in different network(VLAN)?
· Active Directory : Replication
· How to monitor…

vSphere : PowerCLI Getting Started

Hello Guys,This being my first article on Let's support, I would like to take this opportunity and pay homage to our excellent blog author Narayan to present me this wonderful chance.Being a VMware (VMW) and Linux Admin, I've always been fascinated to work on command line utilities (black and white window :)). Mousing around your screen and doing tasks with just lame clicking around are just the right things which frustrate me. For some time now, I've been looking to automate and standardize ESX tasks with scripts and save some productive time for other important tasks.While attending one of the promo sessions from VMW, I was introduced to PowerCLI, the next big command line utility from VMW. PowerCLI gives you the flexibility to connect and work on ESX / ESXi / Virtual center level. PowerCLI is powered and based on Windows PowerShell (works on XP and above). In this article I would like to share my experience with PowerCLI and also help you to install and getting started …

vSphere : Completeness of Virtualization

VMware vSphere is a new product of VMware which supports Cloud level infrastructure. It is released in 2009 with lot of new features  and enhancements. It only available in 64bit vesrion, but supports all types of Virtual Machines (32bit and 64bit). The Management suite includes the following applications.vSphere New Features
1. Storage VMotion
2. Host profiles
3. VM Fault Tolerance
4. vApps
5. vShieldzones
6. Distributed vSwitch
7. Distributed Power ManagementExisting Features
8. VMotion
9. DRS
10. HAStorage VMotion (VIDEO)It is also available in VMware Infrastructure 3. It is a plug-in that needs to be installed on vCenter. Till now we are doing VMotion of VM, means moving the VM from one ESX host to another without downtime while the VM is running. But with SVMotion we can move VM files (.vmdk) from one data store to another without any downtime. This can be done in several cases like, insufficient disk space on Datastore, vmfs upgrade, vmfs maintenance, LUN maintenance etc.Host pr…

VMware Storage : RDM: Raw Device Mappings

Hi Friends,Today i want to post lot of things, as i am not getting enough time on week days. In this post i want to let you know the details about RDM. What is RDM?RDM is nothing but Raw Device Mapping to the Virtual Machine, usually to give storage to the virtual machine we will take some space from the physical hard disk and add it as .vmdk file. This is a standard process. I have a question here, like is it possible to add the LUN directly to the virtual machine instead of adding to the ESX server ? yes it is possible using this technology. When you try to add the HDD to the existing virtual machine you will get some options and RDM is one of them. When you add a LUN using RDM what happens is a file is created on the respective Datastore with the virtual machine files which give access to the actual physical LUN which is allocated for this VM. That means the file acts as a proxy between the VM and actual physical storage. You can access the physical LUN directly from the VM with al…

VMware Storage Configuration Using iSCSI SAN

Hi Friends,As you know already a Datastore is a place where we can store the virtual machine files. And these Datastore's can be implemented using FC SAN, iSCSI SAN and NFS options. All these options are comes under shared storage, that means storage implemented using these technologies can be shared by multiple hosts. Now i want to tell you something about configuring iSCSI SAN for VMware Datastore's. Let me know in the comments, if anything  which is not understandable. So that i will post in clear steps. Thanks a lot for coming to my blog.Many of the features of VMware ESX Server and VMware Virtual Infrastructure will be utilized only when the shared storage available. That applies to all the "cool" features like vMotion, VMHA and DRS etc. A fiber channel (FC) SAN can easily cost as much as a small house and enterprise iSCSI equipment may cost half of that. But for enterprises iSCSI is not recommendable as it does not support high speeds when connected between lon…

Openfiler : Opensource iSCSI SAN Server

For an Openfiler I’ll be using VMware Virtual Appliance that you can download here (x86 VMware Virtual appliance). If you want another version (like x64) or ISO image just go to this url and choose the version you need. I’ll be using VMware Workstation to actually run the Openfiler Virtual Machine. I know the performances will not be excellent but to test all this stuff it’ll be just fine.There is some good documentation about the actual architecture of Openfiler you can have look here. 1.Add Second virtual hard disk to your VM
Before you first start your Openfiler VM, add a second virtual hard disk (as an SCSI hard disk). Like this Openfiler will detect this disk at startup and then you’ll be able to use this disk for your data.2. Start Openfiler VMThen log In remotely via web browser to the ip address which was assigned via DHCP. You will see an image like this. Login with a “Openfiler” as a login and with “password” as a password.3. Then you need to configure Openfiler as a iSCSI ta…