VM /ETC

Posts Tagged ‘replication’

It’s good to see other administrators discussing whether or not to P2V domain controllers, and even better to see that others are recommending the same as I did in my recent post Small business P2V migrations. VMware Communities: VMWare esx 3.5& Windows Server 2003 … is a forum discussion where this topic is discussed in detail. What’s great about this discussion is that it goes beyond the P2V strategy and in to whether or not all DCs in your environment should be VMs.

Some highlights from the forum discussion:

 

“So it is a bad idea to convert dc’s from physical to virtual correct? Read the rest of this entry »

When I hear “we only have 6 servers so our migration to VI should be quick and easy, right?” I hesitate. Not because it can’t be done, but because of how it should be done and the probable challenges. The expectation is usually that the physical servers should be virtualized as is. The reality is often that in order to achieve the best VI design the customer needs to separate applications and services.

A typical small office server infrastructure is usually similar to the following:

Server 1	Domain Controller, DNS, DHCP, WINS
Server 2	Messaging, Backup Domain Controller, DNS, DHCP, WINS
Server 3	Accounting, Finance, misc user and business applications
Server 4	File Server, Database
Server 5	Web, Intranet, FTP, DMZ applications or services, VPN or remote access
Server 6	Antivirus, monitoring, misc administrator applications

The exact placement of the different applications and services varies, but the result is the same. A small company P2V project really should be an infrastructure redesign project so that the features and benefits of VI can be fully leveraged. The following are my recommendations for the VI design of a small company like the example. Read the rest of this entry »

One of the advantages of a virtual infrastructure is the ability to cost effectively replicate your production systems to a secondary disaster recovery environment. Not only can you do this with virtual machines, but there are now several options available to allow physical servers to be replicated to a stand-by VM. This post will briefly cover several products and solutions and provide multiple commercial options and a free alternative. Read the rest of this entry »

One of the engineers from our storage team asked me to join a discussion about whether or not restoring VMs from images made by any of the live VM backup utilities would be a reliable process for a client. I unknowingly joined what was really a battle about whether the client would be better off using SAN based snapshots, host based replication, or live VM imaging specifically for Exchange and SQL VMs. All are proven solutions, and depending on budget, recovery objectives, and service level agreements all solutions could be deployed with confidence. The customer, and this post, is focused on the live VM backup solutions and their reliability for Exchange and SQL. Based on cost of implementation and infrastructure required the VM backup tools are the most affordable and easiest to deploy, but they also leave you with the most uncertainty.

Before continuing I want to point out that normal backup agents still need to be used for Exchange and SQL VMs. Not one of the VM backup solutions can perform application maintenance or specialized backups, like the Exchange Information Store backup for example. Understand that the live VM backup tools only specialize in capturing a quiescent, working image of the VM operating system and application.

First let’s understand what we mean when we say quiescent data. In the latest VMware Virtual Machine Backup Guide quiescing is defined as: Read the rest of this entry »

Too many companies try to implement replication to a DR VI without upgrading the bandwidth between the primary and secondary sites. Let’s look at a simple example that can illustrate what could go wrong with inadequate bandwidth.

A company has 5 VMs that each use 20 GB virtual disks. The data is not too dynamic and data change only averages about 1o% per business day or roughly 1 GB per hr. This data change could be common activity like Active Directory replication, files saved to user home folders, application databases, and email. This is common to a small to medium sized business.

Using the Data Replication Minimum Bandwidth Requirements chart provided by NSI, makers of Double-Take, You can see that the 100 GB falls into the LAN 10Mb/s bandwidth category (in the 10% column). Click the thumbnail image to the left for a better view of the chart. We’ve already proved that this company needs better than a T1, but it’s close enough not to convince those that think their data change will be lower than 10%.

The real “gotcha” is that companies never consider how long it will take to replicate the data. Read the rest of this entry »

These are my notes I used to prepare for a discussion with a client about implementing a secondary site for DR fail over. The client has already virtualized their production data center and is wanting to leverage VI for DR. The point of my discussion is that VI is too often viewed as a “silver bullet” for tough projects like back up and fail over. Yes, there are some specific areas that are easier to implement with VI, but careful consideration and planning must be executed if the overall DR plan is to be successful.

Goals and Objectives – the customer must make important decisions first !

 

· Recovery Time Objectives – acceptable time to start up systems and allow user access

requires server by server analysis

· Recovery Point Objectives – acceptable point in time recovery or start up at secondary site

requires application by application analysis

· Mission Critical Services

which applications & services must be available first.

Read the rest of this entry »

Unfortunately I slept late Thursday morning. Waking up at 7:30 am in Hayward, CA meant that there was no way short of a helicopter I was going to make it to San Francisco before 9. I’m pretty sure my company would not let me expense a helicopter so I decided to catch up on some email from the hotel until traffic burned off. I also had “Smash Head” from the party Weds night!

blog.scottlowe.org has some great notes on this session. Here’s my thoughts on what I missed. Read the rest of this entry »