Wednesday, April 23, 2008

Interview Related Exchange Stuff

Some info on Exchange

Before Installing Exchange Perform the following things:

  1. Make sure AD is looking good in the domain. Run DCDIAG\NETDIAG\EVENTVWR
  2. Make sure we have a connection to a Global Catalog server: 3268 Working(NLTEST)
  3. Make sure DNS name resolution is working fine.
  4. Run Forestprep(AD schema upgrade)\(ENT Admin, Schema Admin, DOmain Admin, Local Machine Admin). {Extends the Active Directory schema to include Exchange-specific classes and attributes} &&& {Creates a container object for the Exchange organization in Active Directory.}
  5. Run Domainprep(AD schema upgrade)\(Domain Admin, Local Machine admin)- Creates Exchange Domain Servers and Exchange Enterprise Servers groups {Creates the Exchange System Objects container, which is used for mail-enabled public
    folders} &&& {Nests the global Exchange Domain Servers into the Exchange Enterprise Servers local group}
  6. Install the following services on the machine {Net Framework \ ASP.Net \ IIS(Internet Information Services) \ WWW Publishing Service \ SMTP Service \ NNTP(Network News Transfer Protocol) Service}
  7. Run Exchange Setup (Must be Local Admin on member server & Exch full admin permissions)

Exchange Tabs under User Properties:

  • Exchange General
  • Exchange Features
  • Exchange Advanced
  • E-Mail Addresses

What if we change the mode from Exch Mixed mode to Native Mode?

  1. You can create query-based distribution groups. A query-based distribution group provides the same functionality as a standard distribution group. However, instead of specifying static user memberships, with a query-based distribution group you can use an LDAP query to build membership in the distribution group dynamically. For more information about query-based distribution groups, see "Managing Recipients and Recipient Policies" in the Exchange Server 2003 Administration Guide (http://go.microsoft.com/fwlink/?LinkId=47617).
  2. Your routing bridgehead server pairs use 8BITMIME data transfers instead of converting to 7-bit. This difference equates to a considerable bandwidth saving over routing group
    connectors.
  3. Routing groups can consist of servers from multiple administrative groups.>You can move Exchange Server 2003 servers between routing groups.
  4. You can move mailboxes between administrative groups.
  5. Simple Mail Transfer Protocol (SMTP) is the default routing protocol.

Note: This change is irreversible.

Difference bet IIS 5.1 and IIS 6.0

IIS 6.0
  • IIS 6.0 provides 2000 application pools. IIS 6.0 operates in worker process isolation
    mode, up to 2000 application pools can be created where each application pool can be
    configured separately. So if one app pool goes down(worker process) u still have the rest on the website running.
  • As IIS 6.0 have many application pools so it provides a well-defined separation of
    applications. Now thousands of applications can run side by side on a single IIS 6.0 server.
  • In IIS 6.0 the webrequest is picked up by HTTP.SYS driver(on port 80) and passed on to
    ASP.Net worker process(asp_wp.exe). This is a 2 Step Process.
  • IIS 6.0 provides error logging in a seprate file from the web logs and also have more
    properties to configure in the error log.
  • IIS 6.0 supports auto restart of failed applications

Worker Process: asp_wp.exe

IIS 5.1

  • With IIS 5.0 all applications are pooled into one application pool which is hosted by
    DLLHost.exe. So if this pool goes down, all the website are inaccessible.
  • With IIS 5.1 the webrequest is picked up on port 80 by HTTP.SYS and then passed on to
    aspnet_isapi.dll and then forwarded to worker process asp_wp.exe. SO this is a 3 Step
    process.

Thursday, September 20, 2007

Friday, August 31, 2007

How VMware works in contrast to Hypervisor?

The most evident and important diff between a HyperVisor and VMware (simillar products) is that Hypervisor is a Technology and VMware and Microsoft Virtual PC are applictions. We can call Hypervisor as an OS that runs directly on a bare-hardware. In contrast products like Microsoft Virtual PC and VMware requires an OS to run on. Once an OS(windows\Linux) is insatalled on Hardware, you can install these products on the OS and then can utilize these products to run various OS. However unlike VMware software HyperVisor runs directly on Bare-Hardware..without the OS. U can think HyperVisor as a BIOS, which is intalled on the Hardware.
Because VMware Server is burdened with the I/O overhead of an existing OS, it is not as efficient as a bare-metal hypervisor. On the other hand, it has a broad driver compatibility because VMware Server can use every hardware device compatible with the host OS. A bare-metal hypervisor typically supports only a limited number of devices since its control OS's kernel is not compiled with many device drivers (in order to keep the kernel small and fast).
Xen is special -- it is a bare-metal hypervisor, but it is designed such that it has broad hardware device compatibility. It relies upon driver domain operating systems, typically the OS in dom-0, but not necessarily, to provide device drivers

Thursday, August 30, 2007

What is HyperVisor?

XENSOURCE-HYPERVISOR
**************************

Microsoft and XenSource: Is there real hope for virtualization interoperability? This article originally appeared on SearchServerVirtualization.com.

Having entered the virtualization space late in the game, Microsoft is working hard to recover lost time.

So far, the Redmond giant's strategy has had three key moves. First, the company announced the Windows Server Virtualization hypervisor and System Center Virtual Machine Manager tool, two competitive products it hopes will challenge VMware Inc. for market leadership. Then, it acquired Softricity Inc., a recognized leader in application virtualization with its SoftGrid product. Finally, it entered into an agreement with XenSource Inc. for virtual machine interoperability between its hypervisor and the most famous open source virtualization platform, Xen.

This last step raised a lot of hackles in the virtualization industry, with reactions from many vendors, including VMware. Customers found themselves faced with uncertainty regarding conflicting information, the complexity of the migrations and the impact on business. Summarizing the key points of any problem always helps to clarify the issues, so here are the key elements in the Microsoft-Xen situation:

Microsoft has been involved in the Xen project since the very beginning. SWsoft Inc. reports Microsoft's upcoming Windows Server Virtualization and Xen hypervisors have a similar architecture.

Xen is open source.
Microsoft Windows Server Virtualization will be out within two years.
VMware has been proposing a virtualization standard for more than a year, but the work has severely slowed down because of differences of opinion, particularly with regard to the XenSource approach.

VMware rarely comments on competitors' moves in the virtualization market, but in less than a day it reacted aggressively against the Microsoft-XenSource agreement.
Xen is adopting a paravirtualization approach, involving guest operating system kernel modification, permitted only on open source platforms.
With the new features inside AMD (SVM) and Intel (VT) processors, users can achieve the same capability to run operating systems with paravirtualization. In the future, new generations of this technology will be able to achieve the same performances.
Virtual Iron Software Inc. publicly announced that its products would be based on Xen, but that the company will dismiss the paravirtualization approach.
Novell released its new operating system with Xen but limited support to its own operating system for virtual machines.

After the Microsoft-XenSource announcement and Novell operating system release, Red Hat Inc. suddenly warned that Xen is not ready for production, despite the big announcement of a comprehensive virtualization strategy on March. Given these points, customers looking at Xen and Windows Server Virtualization as a viable alternative to the existing VMware ESX Server solution have now to ask themselves:
Why key Xen supporters are offering limited support for it even after implementing the hypervisor on their commercial solutions.
Why Microsoft didn't opt to participate in VMware and Xen hypervisor standardization works instead of working on an interoperability solution.
Why Microsoft needed XenSource to implement Xen interoperability when it knows the project so well.

Given licensing and support issues, why moving a native virtual machine from its hypervisor to another should be better than committing a physical-to-virtual (P2V) migration. Answering those questions leads to some notable conclusions. First of all, the recently announced Microsoft-XenSource deal has value purely as a political pact. Considering that it's impossible for XenSource to benefit from Microsoft's know-how because of licensing incompatibilities, the agreement is unilateral, providing technical benefits to Microsoft only -- if there are any. The main goal will be to verify if a XenEnterprise Linux virtual machine is as fast as, or faster than, the same machine built from scratch on Windows Server Virtualization. This will be impossible until both companies release their products, assuming hypervisors will feature the interoperability patch at that time.

Another important conclusion is that Xen is a project with high potential but an uncertain destiny. In the immediate future, customers who decide to adopt it even through the Novell or Red Hat operating systems, will live in a half-supported world where they cannot use the hypervisor for anything other than virtualizing the same platform. In this scenario, OS partitioning products like SWsoft Virtuozzo are a better fit.

In the long run, assuming the next-generation processors will be able to provide the same performance paravirtualization offers today, Xen will lose its technical advantage and be obliged to compete au pair with other products. At that point, customers will need a compelling reason to adopt the open source hypervisor, without the experience of VMware or the support capabilities of Microsoft.

Tuesday, August 28, 2007

1st Post

Hi guys,

This is my first ever blog on "Active Directory" (AD). I hope all of you, interested in Active Directory, would find something new on this Blog. Our Aim is to share technical know-how on AD. Not only AD we hope for posts\articles\reviews that can shed some light on NFS(Network File System) & Active Directory. There are lots of blogs out there that talk too techinal for most of us. Our Aim is to answer most of your queries regarding AD, no matter how small and non-technical it may sound to people working with IT. "Every Drop Counts".Please share your comments and reviews. Hope for your co-operation, to make this blog a success.

Thanks:
Punit(AD-Engg)