Using the AWS Storage Gateway to Backup to S3 using Zerto

November 20, 2020November 20, 2020 Gene Torres Leave a comment

This one took a while to get out there, but alas, it has been published for public consumption.

With that, I’m happy to be able to share this new whitepaper with the community, as it was not only great to hear that Zerto supports it, but it was also a blast testing and documenting the solution!

As a part of the Zerto 8.0 launch earlier this year (March 22, 2020 to be exact), the AWS Storage Gateway was officially announced as being supported as a Zerto LTR (Long Term Retention/Backup) target, which effectively enables you to send your Zerto backups to Amazon S3.

Sure, as of Zerto 8.5, you can actually configure Azure Blob (Hot/Cold) Storage or Amazon S3 (with Infrequent Access Tier support) for Zerto backups, which will effectively enable you to send backups directly to the public clouds via HTTPs.

That said, where does the AWS Storage Gateway fit into the picture? When or why should I use it as opposed to sending my backups directly to the cloud?

In a nutshell, the difference between what Zerto does in 8.5, and what you get by using the AWS Storage Gateway is that with the storage gateway, you are getting a cached copy of your backup data on-premises, which resides outside of Zerto’s short term journal. Here’s how that topology looks:

Topology for the AWS Storage Gateway in a Zerto Environment

What we see here is that the Storage Gateway sits on-premises, and serves as a cache location for most frequently accessed data. You connect it to Zerto as an NFS or SMB repository (SMB must be used for indexing, btw) and configure your Virtual Protection Groups to send backups to this repository.

What you will get is a Zerto backup that will complete locally, and then the Storage Gateway asynchronously replicates that data out to an S3 bucket of your choosing. If you need to restore something from the backups (if your short term journal doesn’t contain what you need), you can quickly restore that data from the storage gateway without having to pull the data back down from S3.

Now that I’ve set the stage – without further ado (yeah I googled this to be sure I used the correct term), here’s the link to the whitepaper: https://bit.ly/2Krs14y

As an added bonus, if you are strapped for time and don’t want to read, I’ve also created a video that walks through the same steps to install and configure the AWS Storage Gateway for use with Zerto:

If you have found this useful, please be social and share! As usual, thanks for reading, and watching. Please leave any comments and questions below!

Cheers!

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Migrate VM from Hyper-V to vSphere with Pre-Installed VMware Tools

June 17, 2020February 2, 2023 Gene Torres 11 Comments

Note: This post is written specifically for VMware Tools 10. If you’re looking for a procedure that works with VMware Tools 11 or VMware Tools 12, you can see my latest blog post here.

One of things I rarely get to do is work with Hyper-V, however, I’m starting to get more exposure to it as I encounter more organizations that are either running all Hyper-V or are doing some type of migration between Hyper-V and vSphere.

One of the biggest challenges that I’ve both heard and encountered in my own testing is really around drivers. If you’re making the move from Hyper-V to vSphere, you’re going to have to figure out how to get your network settings migrated along with the virtual machines, whether manually or in a more automated way.

And yes! You can definitely use Zerto as the migration vehicle and take advantage of benefits like:

Non-disruptive replication
Automatic conversion of .vhdx to .vmdk (and vice versa)
Non-disruptive testing before migrating
Boot Order
Re-IP

For re-IP operations , Zerto requires that VMware Tools is installed running on the VMs you want to protect.
Zerto Administration Guide for vSphere

There are two ways to accomplish a cross-hypervisor migration or failover with Zerto.

Installing the VMware Tools is going to be required either way. If you choose to install the VMware Tools before migrating or protecting, you are going to get much better results.

Post-installation of the VMware Tools will prevent the capability to automatically re-IP or even keep the existing network settings, therefore, you will end up having to hand-IP every VM you migrate/failover, which seriously cuts into any established recovery time objective (RTO) and leaves more room for human error.

Overview

We will walk through what you need to do in order to get VMware Tools prepared for installation on a Hyper-V virtual machine. After that, there is a video at the end of this post that will pick demonstrate successful pre-installation of VMware Tools, replication, and migration of a VM from Hyper-V.

At the time of this writing, the versions of Zerto, Hyper-V, and vSphere that I have performed the steps that follow are:

Zerto 8.0
Hyper-V 2016
vSphere 6.7 (VMware Tools from 6.7 as well)

I also wanted to give a shout out to Justin Paul, who had written a similar blog post about this same subject back in 2018. You can find his original post here: https://bit.ly/3dfWKdm

Pre-Requisites

Like a recipe, you’re going to need a few things:

VMware Tools

You will need to obtain a copy of the VMware Tools, and it must be a version supported by your version of vSphere. You can use this handy >>VMware version mapping file<< to see what version of the tools you’d need.

You can get the tools package by mounting the VMware Tools ISO to any virtual machine in your vSphere environment, browsing the virtual CD-ROM, and copying all the files to your desktop. If you don’t have an environment available, you can also >>download the installer<< straight from VMware (requires a My VMware account).

Since you only need a few files from the installer package, start the installer on your desktop and wait for the welcome screen to load. Once that screen loads, if you’re on a physical machine (laptop, PC, etc…), you’re going to get a pop-up stating that you can only install VMware Tools inside a virtual machine. DO NOT dismiss this pop-up just yet.

Go to Start > Run and type in %TEMP% , the press Enter.
Look for a folder that follows this naming convention {VVVVVVVV-WWWW-XXXX-YYYY-ZZZZZZZZZZZZZ} followed by “-setup” appended to it and open it.
Copy the following 3 files to a folder on your desktop: vcredist_x64.exe, vcredist_x86.exe, and VMware Tools64.msi
Once you’ve saved the files somewhere else, you can now dismiss the popup and exit the VMware Tools installer.

Microsoft Orca

Microsoft Orca is a database table editor that can be used for creating and editing Windows installer packages. We’re going to be using it to update the VMware Tools MSI file we just extracted in the previous steps, to allow it to be installed within a Hyper-V virtual machine.

Orca is part of the Windows SDK that can be downloaded from Microsoft (https://bit.ly/3d7aWoZ). Download the installer, and not the ISO (it’s easier to get exactly what you want this way).

Run the installer and when you get to the screen where you’ll need to Select the features you want to install, select only MSI tools and complete the installation.

After installation is completed, you can search your start menu for “orca” or browse to where it was installed to and launch Orca.

Edit VMware Tools MSI with Orca

Now that we’ve got the necessary files we need, and Orca installed, we’re going to need to edit the VMware Tools MSI to remove an installer pre-check that prevents installation on any other platform than vSphere.

Launch Orca
Click Open, and browse to where you saved VMware Tools64.msi, select it, and click Open.
In the left window pane labeled Tables, scroll down and click on InstallUISequence.
In the right window pane, look for the line that says VM_CheckRequirements. Right-click on this entry, and select Drop Row.

VM_CheckRequirements > Drop Row”>
Click save on the toolbar, and close the MSI file. You can also exit Orca now.

What next?

I’ve made you read all the way down to here to tell you that if you want to skip the previous steps and are looking to do this for vSphere 6.7, I have a copy of the MSI that is ready for installation on a Hyper-V virtual machine. If you need it, send me a message on Twitter: @eugenejtorres

Now that you’ve got an unrestricted copy of the VMware Tools MSI package. Copy the VMware Tools MSI along with the vc_redist(x86/x64) installers to your target Hyper-V VMs (or a network share they can all reach), and start installing.

Important: When installing VMware Tools on the Hyper-V virtual machine, you may get the following error:

If you receive the error above, it means you’re missing Microsoft Visual C++ 2017 Redistributable (x64) on that VM.

If this is the case, click cancel and exit the VMware Tools installer. Run the vcredist_x64.exe installer that you copied earlier, and then retry the VMware Tools Installer.

Demo

Since you’ve gotten this far, the next step is to test to validate the procedure. Take a look at the video below to see what migration via Zerto looks like after you’ve taken the steps above.

If you have any questions or found this helpful, please comment. If you know someone that needs to see this, please share and socialize! Thanks for reading!

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How To: Migrate Windows Server 2003 to Azure via Zerto, Easily

January 6, 2020January 7, 2020 Gene Torres Leave a comment

So since Microsoft has officially ended extended support for Windows Server on July 15, 2015, that means that you may not be able to get support or any software updates. While many enterprises are working towards being able to migrate applications to more current versions of Windows, alongside initiatives to adopt more cloud services; being able to migrate the deprecated OS to Azure is an option to enable that strategy and provide a place for those applications to run in the meantime.

Be aware though that although Microsoft support (read this) may be able to help you troubleshoot running Windows Server 2003 in Azure, that doesn’t necessarily mean they will support the OS. That said, if you are running vSphere on-premises and still wish to get these legacy systems out of your data center and into Azure, keep reading and I’ll show you how to do it with Zerto.

Please note that I’ve only tested this with the 64-bit version of the OS (Windows Server 2003 R2). EDIT: this has also been verified to work on the 32-bit version of the OS – Thanks Frank!)

The Other Options…

While the next options are totally doable, think about the amount of time involved, especially if you have to migrate VMs at scale. Once you’re done taking a look at these procedures, head to the next section. Trust me, it can be done more easily and efficiently.

Migrate your VMs from VMware to Hyper-V
- … Then migrate them to Azure. Yes, it’s an option, but from what I’ve read, it’s really just so you can get the Hyper-V Integration Services onto the VM before you move it to Azure. From there, you’ll need to manually upload the VHDs to Azure using the command line, followed by creating instances and mounting them to the disks. Wait – there’s got to be a better way, right?
Why migrate when you can just do all the work from vSphere, run a bunch of powershell code, hack the registry, convert the disk to VHD, upload, etc… and then rinse and repeat for 10’s or 100’s of servers?
- While this is another way to do it, take a look at the procedure and let me know if you would want to go through all that for even JUST ONE VM?!
Nested Virtualization in Azure
- Here’s another way to do it, which I can see working, however, you’re talking about nesting a virtual environment in the cloud and perhaps run production that way? While even if you have Zerto you can technically do this, there would have to be a lot of consideration that goes in to this… and likely headache.

Before You Start

Before you start walking through the steps below, this how-to assumes:

You are running the latest version of Zerto at each site.
You have already paired your Azure ZCA (Zerto Cloud Appliance) to your on-premises ZVM (Zerto Virtual Manager)
You already know how to create a VPG in Zerto to replicate the workload(s) to your Azure subscription.

Understand that while this may work, this solution will not be supported by Zerto, this how-to is solely written by me, and I have tested and found this to work. It’s up to you to test it.

Additionally, this is likely not going to get any support from Microsoft, so you should test this procedure on your own and get familiar with it.

This does require you to download files to install (if you don’t have a Hyper-V environment), so although I have provided a download link below, you are responsible for ensuring that you are following security policies, best practices, and requirements whenever downloading files from the internet. Please do the right thing and be sure to scan any files you download that don’t come directly from the manufacturer.

Finally – yeah, you should really test it to make sure it works for you.

Migrating Legacy OS Using Zerto

Alright, you’ve made it this far, and now you want to know how I ended up getting a Windows Server 2003 R2 VM from vSphere to Azure with a few simple steps.

Step 1: Prepare the VM(s)

First of all, you will need to download the Hyper-V Integration Services (think of them as VMware Tools, but for Hyper-V, which will contain the proper drivers for the VM to function in Azure).

I highly suggest you obtain the file directly from Microsoft if at all possible, or from a trustworthy source. At the least, deploy a Hyper-V server and extract the installer from it yourself.

If you have no way to get the installer files for the Hyper-V Integration Services, you can download at your own risk from here. It is the exact same copy I used in my testing, and will work with Windows Server 2003 R2.

Obtain the Hyper-V Integration Services ISO file. (hint: look above)
Once downloaded, you can mount the ISO to the target VM and explore the contents. (don’t run it, because it will not allow you to run the tools installation on a VMware-hosted workload).
Extract the Support folder and all of it’s contents to the root of C: or somewhere easily accessible.
Create a windows batch file (.bat) in the support folder that you have just extracted to your VM. I put the folder in the root of C:, so just be aware that I am working with the C:\Support folder on my system.
For the contents of the batch file, change directory to the C:\Support\amd64 folder (use the x86 folder if on 32-bit), then on the next line type: setup.exe /quiet (see example below). The /quiet switch is very important, because you will need this to run without any intervention.
Save the batch file.
On the same VM, go to Control Panel > Scheduled Tasks > Add Scheduled Task. Doing so will open the Scheduled Task Wizard.
Click Next
Click browse and locate the batch file you created in step 5-6, and click open
Select when my computer starts, and click next
Enter local administrator credentials (will be required because you will not initially have network connectivity), and click next
Click Finish

Step 2: Create a VPG in Zerto

The previous steps will now have your system prepared to start replicating to Azure. Furthermore, what we just did, basically will allow the Hyper-V Integration Services to install on the Azure instance upon boot, therefore enabling network access to manage it. It’s that simple.

Create the VPG (Virtual Protection Group) in Zerto that contains the Windows Server 2003 R2 VM(s) that you’ve prepped, and for your replication target, select your Microsoft Azure site.

If you need to learn how to create a VPG in Zerto, please refer to the vSphere Administration Guide – Zerto Virtual Manager documentation.

Step 3: Run a Failover Test for the VPG

Once your VPG is in a “Meeting SLA” state, you’re ready to start testing in Azure before you actually execute the migration, to ensure that the VM(s) will boot and be available.

Using the Zerto Failover Test operation will allow you to keep the systems running back on-premises, meanwhile booting them up in Azure for testing to get your results before you actually perform the Move operation to migrate them to their new home.

In Zerto, select the VPG that contains the VM(s) you want to test in Azure (use the checkbox) and click the Test button.
Validate the VPG is still selected, and click Next.
The latest checkpoint should already be selected for you. Click Next
Click Start Failover Test.

After you click Start Failover Test, the testing operation will start. Once the VM is up in Azure, you can try pinging it. If it doesn’t ping the first time, reboot it, as the Integration Services may require a reboot before you can RDP to it (I had to reboot my test machine).

When you’re done testing, click the stop button in Zerto to stop the Failover Test, and wait for it to complete. At this point, if everything looks good, you’re ready to plan your migration.

If you did anything different than what I had done, remember to document it and make it repeatable :).

Next Steps

Once you’ve validated that your systems will successfully come up you can then schedule your migration. When you perform the migration into Azure, I recommend using the Move Operation (see image below), as that will be the cleanest way to get the system over to Azure in an application-consistent state with no data loss, as opposed to seconds of data loss and a crash-consistent state that the failover test, or failover live operations will give you.

Note: Before you run the Move Operation, it will be beneficial to uninstall VMware Tools on the VM(s) that you are moving to Azure. It has been found that not doing so will not allow you to uninstall them once in Azure.

Move Operation

Recommendations before you migrate:

Document everything you do to make this work. (it may come in handy when you’re looking for others to help you out)
Be sure to test the migration beforehand using the Failover Test Operation.
Check your Commit settings in Zerto before you perform the Move Operation to ensure that you allow yourself enough time to test before committing the workload to Azure. Current versions of Zerto default the commit policy to 60 minutes, so should you need more time, increase the commit policy time to meet your needs.
Be sure to right-size your VMs before moving them to the cloud. If they are oversized, you could be paying way more in consumption than you need to with bigger instance sizes that you may not necessarily need.

That’s it! Pretty simple and straightforward. To be honest, obtaining a working copy of Windows Server 2003 R2 and the Hyper-V Integration Services took longer than getting through the actual process, which actually worked the first time I tried it.

If this works for you let me know by leaving a comment, and if you find this to be valuable information that others can benefit from, please socialize it!

Cheers!

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Zerto: Can Failover Live Be Used for a Datacenter Migration, Consolidation, or HW Refresh?

September 11, 2018September 11, 2018 Gene Torres Leave a comment

The answer is yes, if you really wanted to… however, there’s another feature of Zerto that will allow you to perform a much “cleaner” migration of your VM(s) with a more planned approach.

This feature may not be easily located, as it’s found within the Actions menu in the Zerto UI, but it’s actually a very valuable one that basically allows you to migrate VMs from one location to another (cluster to cluster, vCenter to vCenter, vSphere <> Hyper-V, On-Prem to Public Cloud, Site to Site – even from one vendor’s hardware to another) with no data loss. That’s right, an RPO of ZERO.

Failover Live (FOL)

First off, since the title of this blog post mentions “Failover Live”, or as we abbreviate it as FOL, lets talk about that method first. What is the FOL process, and how does it work?

The FOL process is an operation that should be used following a disaster to recover your protected VMs in a recovery site, or in the event the protected site ZVM is not available. The main thing to note here is that when you execute a FOL, Zerto will default to the latest checkpoint, or you can select a previous checkpoint in time to recover to (usually within seconds of each other). Additionally, you have the option to either leave the VMs in the group running, power them off, or force a shutdown.

Essentially what this means is that when using FOL, Zerto is expecting that there’s been an unplanned environment disruption of some sort and you need to resume production as quickly as possible in your recovery site.

Here’s the workflow for a failover operation. You can download a PDF version of this diagram here.

Zerto Virtual Replication Failover Live Workflow Diagram

Please note, that the workflow objects in yellow include some decisions you will need to make based on your type of disruption as it relates to the power state of the VMs in your protected site (Shutdown (gracefully), Leave Powered On, or Force Shutdown).

Regarding my earlier comment about ZERO data loss, this method will only get you to the latest checkpoint when the outage was detected, or a previous checkpoint. You can choose what point in time to recover to, which in either option, will be a crash-consistent state which may not be desired for something like a migration project.

For additional detail about the Failover Live (FOL) process and how it works, including considerations, see the Zerto Virtual Manager Administration Guide for vSphere.

Move VPG

As opposed to an unplanned disruption to your environment, the “Move VPG” operation in Zerto is recommended when you’re performing a planned migration whether it be your DR site, public cloud, new hardware, or other datacenter. The difference here is that when you perform a planned migration of your virtual machine(s) to a recovery site, Zerto assumes that both sites are up and healthy and that you are performing a relocation of the virtual machine(s) in a controlled/orderly fashion – with the expectation of no data loss.

Here is the workflow for a Move VPG operation. You can download a PDF version of this diagram here.

Zerto Virtual Replication Move VPG Workflow Diagram

So as you can see from the workflow above, the steps are a bit different than a failover live, as there are actually some steps taken in the protected site before VMs are brought up in the recovery site to ensure that what is booted is in the exact same state as the source copy.

For additional detail about the Move VPG process and how it works, see the Zerto Virtual Manager Administration Guide for vSphere.

Summary

While you can still use the FOL process to migrate VMs from one location to another, there is still going to be some level of data loss and a crash consistent boot.

To ensure you don’t lose any data (even data that may be in memory at the time you perform a FOL), the “Move VPG” operation will take care of automating the safe/graceful shutdown of a VM and replicate any remaining data before powering up in the recovery site.

When performing either operation, be sure to verify your commit policy as well, because you would want to make sure that the recovered/migrated VM is in a usable state before committing it to the recovery location because once you commit the change, you must wait for promotion and reverse protection (delta sync) to take place before you can perform a failback. Both options will allow you the ability to rollback without commit, but behave differently in terms of the expected state of the protected site.

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Configuring AWS for Zerto Virtual Replication

March 30, 2018April 4, 2018 Gene Torres Leave a comment

By now, it’s no secret that the IT Resilience Platform that Zerto has come to be known as offers complete flexibility when it comes to multi-cloud agility. This agility allows businesses to accelerate their digital transformation and truly take advantage of what the public cloud platform offers – ensuring even more freedom to choose your cloud and to be able to replicate workloads to, from, and even between public clouds. As there have been great improvements in Zerto’s any-to-any story, one in particular I’d like to focus on in this article is AWS (Amazon Web Services).

Starting with Zerto Virtual Replication 6.0, customers now have:

Orchestration allowing not only targeting AWS for DR or for workload migration, but now the ability to come back out of AWS to on-premises datacenters, or even the ability to replicate between public cloud providers (AWS, Microsoft Azure, IBM Public Cloud) and Cloud Service Providers (CSPs).
Zerto Analytics visibility between all sites, including public cloud, now with network statistics and 30-day history.

Now, while these improvements are exciting and offer even more cloud agility to customers, one can’t help but realize that before you can actually start taking advantage of ZVR 6.0 to achieve a hybrid cloud architecture or DR in the cloud (specifically AWS), there are some pre-requisites to complete before doing so. That said, meeting those requirements may not seem as intuitive as you’d hope at first glance.

While having a cloud use-case is usually the first step, and is determined by business requirements – the challenge lies within understanding what exactly needs to be configured in AWS for ZVR functionality, and how to accomplish it. If you take a look below, the workflow itself is a multi-step process that may not be very easy to perform, until now.

ZVR AWS Workflow — Figure 1: Configuring AWS for ZVR – Workflow

In my usual fashion of wanting to know exactly how things are done and then sharing it with everyone else, I’ve written a how-to document for configuring AWS for Zerto Virtual Replication, which I am happy to say has been turned into an official Zerto whitepaper and is now available for download!

>> Whitepaper – Configuring AWS for Zerto Virtual Replication <<

As usual, feedback, is welcomed with open arms. If you find this useful, please share and be social!

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Single vCenter, Single ZVM, and Recovering Zerto in a Failure Scenario

March 5, 2018March 12, 2018 Gene Torres 4 Comments

As a follow-up to my previous blog entry titled “Zerto Virtual Manger Outage, Replication, and Self-Healing“, which covers a ZVM failure scenario in an environment with paired ZVMs and two vCenters, I also decided to test and document what I found to be a useful solution to being able to recover from a failed ZVM in an environment where there is only one vCenter and one instance of Zerto Virtual Replication installed. Granted, this is generally not a recommended deployment topology due to potentially having a single point of failure, this type of deployment does exist, and this should provide a suitable solution to allow recovery.

The following has been successfully tested in my lab, which is a vSphere environment, but I also do anticipate that this solution can also be carried over to a Hyper-V environment; which I’m hoping to test soon.

Since my lab originally consisted of two vCenters and two ZVMs, I first had to tear it down to become a single vCenter and single ZVM environment for the test. Here is what I did, should you want to test this on your own before deciding whether or not you want to actually deploy it in your environment.

Disclaimer:

Once again, this is not generally a recommended configuration, and there are some caveats similar to the referenced blog entry above, but with that said, this will allow you to be able to recover if you have Zerto deployed in your environment as described above.

Considerations

Please note that there may be some things to look out for when using this solution because of how the journal contains data until the checkpoints have been committed to the replica disk:

Journal disk being added at the time of a ZVM failure
VRA installation, new VRA installation at the time of a ZVM failure
Changes made to protected VMs (VMDK add) may not be captured if coinciding with a ZVM failure
VPG settings changed at the time of a ZVM failure, such as adding/removing a VM from a VPG

Based on additional testing I’ve done, it makes best sense to keep the journal size of the VPG protecting the ZVM as short as possible because any changes that occur to the ZVM (any of the above) will first go to the journal before aging out and being committed to the replica disk. If those changes don’t commit to the disk, they will not appear in the UI when the ZVM is recovered using this method.

This was found by creating a VPG to protect another set of workloads, and then 10 minutes later, running through the recovery steps for the ZVM. What I didn’t account for here is the FIFO (first-in-first-out) nature of the journal. Because the change I had made resided within journal for the protected ZVM, it did not get a chance to age out to disk. Recovering from the replica did not include the new VPG.

As a result, the recommendation for journal history when protecting the ZVM would be 1 hour (the minimum) – meaning your RPO for the ZVM will be 1 hour.

Setup the Test Environment

Before you can test this, you will need to configure your lab environment for it. The following assumes your lab consists of two vCenters and 2 installations of Zerto Virtual Replication. If your lab only has 1 vCenter, simply skip the “lab recovery site” section and move to the “lab protected site” steps.

In lab recovery site:

Delete all existing VPGs
Delete VRAs (via the ZVM UI)
Un-pair the two ZVR sites (in the sites tab in ZVM UI)
Remove hosts from recovery site vCenter

In lab protected site:

[Optional] Create a new cluster, and add the hosts you removed from your recovery site.
Deploy VRAs any hosts you’ll be using in for the test.
Configure VPGs.

Protect the ZVM using Zerto

One thing I’ve wondered about that I finally got around to testing is actually protecting the ZVM itself using ZVR. I’m happy to say, it appears to work just fine. After all, Zerto does not make use of agents, snapshots, or disrupt production for that matter, as the technology basically replicates/mirrors block writes from the protected to the recovery site after they’re acknowledged via the virtual replication appliances, not touching the protected workload.

Protecting the ZVM is as simple as protecting any other application, via a VPG (Virtual Protection Group). While you can likely protect the ZVM via storage snaps and replication, you’re still not going to get an RPO anywhere close to what Zerto itself can provide, which is typically in seconds – many cases single-digit seconds. What this means, is that your amount of data loss, in the case of the ZVM, will likely be in minutes, even shorter if you can automate the recovery portion of this solution via scripting.

So, a few things to make this solution easier when creating the VPG to protect the ZVM:

When selecting your default recovery server for the VPG that protects the ZVM, select a host, as opposed to a cluster. This allows you to easily locate the VRA responsible for protecting the ZVM. Further on through this article, you’ll see why.
Select a specific datastore for recovery. You can select a datastore cluster, but for the same reasons as above, selecting a specific datastore allows you to easily locate the disk files for the “recovery replica” of the ZVM in the event of a failure.
Select the production network/portgroup that houses the production IP space for the ZVM (Recovery tab of VPG creation wizard). We will not be changing the IP address.
Do not change the IP address for failover/move or test (in the NICs tab of the VPG creation wizard).

Once you’ve created the VPG, allow initial sync to complete. As you can see below, I now have a VPG containing the ZVM. Please note that I’m protecting only the ZVM because I am using the embedded SQL CE database. Using an external SQL server for the ZVR database will require additional planning. Once initial sync has been completed, you’re ready to begin the actual failure test and recovery.

VPG List - Protecting ZVM

Simulate a Failure of the Primary ZVM

In order to test the recovery, we will need to simulate a failure of the Primary ZVM.

Power off the ZVM. Optionally, you can also go as far as deleting it from disk. Now you know there’s no coming back from that scenario. The ZVM will be gone.

Recover the ZVM Using the Replica

If you remember form the blog post linked at the beginning of this one, even if the ZVM is down, the VRAs are still replicating data. Knowing that, the VRA in the recovery site (in this case on the recovery host) will have a lock on the VMDK(s) for the ZVM. That is why I mentioned it would be good to know what host you’re replicating the ZVM to.

IMPORTANT: Before you can start recovering, you will need to shutdown the VRA on the host specified for recovery. Doing so will ensure that any lock on the VMDK(s) for the replica will be released.
Once the VRA has been shutdown, open the datastore browser and move or copy the VMDK(s) out of the VRA folder to another folder. By doing this, you’re making sure that if that VRA comes back up before you can delete the VPG protecting the ZVM, there will not be a conflict/lock. If you select to copy the files, rather than move them, then you can use the existing replica as a pre-seed to re-protect the ZVM.
Create a new VM using the vSphere client.
Select to create a Custom virtual machine.
Provide a name for the VM that doesn’t already exist in vCenter if you did not delete the original “failed” ZVM. This ensures there won’t be a naming conflict.
Select the datastore where you copied the replica VMDK(s) to.
Select the Virtual Machine Version. In this case, you can leave the default, which will be the latest version supported by vSphere version.
Select the OS version for the ZVM.
Select the number of vCPUs required. (Match what the original ZVM had)
Select the amount of memory to allocate to the VM. (Match what the original ZVM had)
Select the PortGroup and Adapter type and make sure it’s set to connect at power on. This should match the original. My original ZVM had been configured with VMXNET3, so that’s what I selected.
Select the SCSI controller to use. Again, try to match the original. Mine was LSI Logic SAS.
On the Select a Disk screen, select Use an existing virtual disk.
Browse to the location of the ZVM replica’s VMDK(s) you copied, and select the disk and click OK.
Leave the advanced options at default.
On the summary screen, click Finish.
When the creation is completed, power on the VM, open the console, and watch it boot up. At this point, DO NOT power on the VRA that you previously shutdown. There will be some cleanup, especially if you did not copy the VMDK(s) to another location.

Power on new VM created using existing disk.

Clean-up

Once the recovered ZVM has booted up, go ahead and log in to the Zerto UI. Don’t be alarmed that everything is red. This is because the ZVM is coming up from being down for a while, and it needs to run some checks, and get re-situated with the VRAs and begin creating new checkpoints again. Once that process completes, as we saw in the previous blog article (referenced at the beginning of this one), things will start to go green and into a “Meeting SLA” state.

Click on the VPGs tab.
Locate the VPG previously created to protect the ZVM, and delete it. If you want to retain the original replica disks as a pre-seed, make sure you select the checkbox labeled Keep the recovery disks at the peer site. Please note that because the VRA that was protecting this VPG is still down, you may need to click delete again, and force the deletion of the VPG.
Once the VPG is deleted, go ahead and power on the VRA you previously shutdown.

Verify ZVR Functionality

Now that we’ve cleaned up and powered the VRA back up, you can verify that ZVR is working again, and the ZVM is performing its duty of creating and tracking checkpoints in the journal again. You can do this by starting to initiate a failover test and clicking to see what checkpoints are available, or by attempting to recover a file from the journal from any one of the VPGs.

Validate checkpoint functionality

(Above) you can see when the ZVM went down, and when it started creating and tracking checkpoints again.

Validate JFLR

(Above) Restored a file from the Journal.

Summary

While this is not an optimal/recommended configuration, through testing and validation, we have seen that even in a single ZVM, single vCenter environment, being able to recovery the platform that is providing your resiliency services is completely possible. Granted, there will be some data loss (RPO) on the ZVM itself, despite being down for time between the failure and the recovery, Zerto Virtual Replication is clearly able to pick up where it left off, and resume protection of your environment.

If you found this to be useful, please share, comment, and let me if you’ve tried this for yourself!

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Zerto Virtual Manager Outage, Replication, and Self-Healing

February 14, 2018February 15, 2018 Gene Torres 1 Comment

I’ve decided to explore what happens when a ZVM (Zerto Virtual Manager) in either the protected site or the recovery site is down for a period of time, and what happens when it is back in service, and most importantly, how an outage of either ZVM affects replication, journal history, and the ability to recover a workload.

Before getting in to it, I have to admit that I was happy to see how resilient the platform is through this test, and how the ability to self-heal is a built in “feature” that rarely gets talked about.

Questions:

Does ZVR still replicate when a ZVM goes down?
How does a ZVM being down affect checkpoint creation?
What can be recovered while the ZVM is down?
What happens when the ZVM is returned to service?
What happens if the ZVM is down longer than the configured Journal History setting?

Acronym Decoder & Explanations

ZVM	Zerto Virtual Manager
ZVR	Zerto Virtual Replication
VRA	Virtual Replication Appliance
VPG	Virtual Protection Group
RPO	Recovery Point Objective
RTO	Recovery Time Objective
BCDR	Business Continuity/Disaster Recovery
CSP	Cloud Service Provider
FOT	Failover Test
FOL	Failover Live

Does ZVR still replicate when a ZVM goes down?

The quick answer is yes. Once a VPG is created, the VRAs handle all replication. The ZVM takes care of inserting and tracking checkpoints in the journal, as well as automation and orchestration of Virtual Protection Groups (VPGs), whether it be for DR, workload mobility, or cloud adoption.

In the protected site, I took the ZVM down for over an hour via power-off to simulate a failure. Prior to that, I made note of the last checkpoint created. As the ZVM went down, within a few seconds, the protected site dashboard reported RPO as 0 (zero), VPG health went red, and I received an alert stating “The Zerto Virtual Manager is not connected to site Prod_Site…”

The Zerto Virtual Manager is not connected to site Prod_Site

Great, so the protected site ZVM is down now and the recovery site ZVM noticed. The next step for me was to verify that despite the ZVM being down, the VRA continued to replicate my workload. To prove this, I opened the file server and copied the fonts folder (C:\Windows\Fonts) to C:\Temp (total size of data ~500MB).

As the copy completed, I then opened the performance tab of the sending VRA and went straight to see if the network transmit rate went up, indicating data being sent:

VRA Performance in vSphere, showing data being transmitted to remote VRA in protected site.

Following that, I opened the performance monitor on the receiving VRA and looked at two stats: Data receive rate, and Disk write rate, both indicating activity at the same timeframe as the sending VRA stats above:

Data receive rate (Network) on receiving/recovery VRA Disk write rate on receiving/recovery VRA

As you can see, despite the ZVM being down, replication continues, with caveats though, that you need to be aware of:

No new checkpoints are being created in the journal
Existing checkpoints up to the last one created are all still recoverable, meaning you can still recover VMs (VPGs), Sites, or files.

Even if replication is still taking place, you will only be able to recover to the latest (last recorded checkpoint) before the ZVM went down. When the ZVM returns, checkpoints are once again created, however, you will not see checkpoints created for the entire time that ZVM was unavailable. In my testing, the same was true for if the recovery site ZVM went down while the protected site ZVM was still up.

How does the ZVM being down affect checkpoint creation?

If I take a look at the Journal history for the target workload (file server), I can see that since the ZVM went away, no new checkpoints have been created. So, while replication continues on, no new checkpoints are tracked due to the ZVM being down, since one of it’s jobs is to track checkpoints.

Last checkpoint created over 30 minutes ago, right before the ZVM was powered off.

What can be recovered while the ZVM is down?

Despite no new checkpoints being created – FOT or FOL – VPG Clone, Move, and File Restore services are still available for the existing journal checkpoints. Given this was something I’ve never tested before, this was really impressive.

One thing to keep in mind though is that this will all depend on how long your Journal history is configured for, and how long that ZVM is down. I provide more information about this specific topic further down in this article.

What happens when the ZVM is returned to service?

So now that I’ve shown what is going on when the ZVM is down, let’s see what happens when it is back in service. To do this, I just need to power it back up, and allow the services to start, then see what is reported in the ZVM UI on either site.

As soon as all services were back up on the protected site ZVM, the recovery site ZVM alerted that a Synchronization with site Prod_Site was initiated:

Synchronizing with site Prod_Site

Recovery site ZVM Dashboard during site synchronization.

The next step here is to see what our checkpoint history looks like. Taking a look at the image below, we can see when the ZVM went down, and that there is a noticeable gap in checkpoints, however, as soon as the ZVM was back in service, checkpoint creation resumed, with only the time during the outage being unavailable.

Checkpoints resume

What happens if the ZVM is down longer than the configured Journal History setting?

In my lab, for the above testing, I set the VPG history to 1 hour. That said, if you take a look at the last screen shot, older checkpoints are still available (showing 405 checkpoints). When I first tried to run a failover test after this experiment, I was presented with checkpoints that go beyond an hour. When I selected the oldest checkpoint in the list, a failover test would not start, even if the “Next” button in the FOT wizard did not gray out. What this has lead me to believe is that it may take a minute or two for the journal to be cleaned up.

Because I was not able to move forward with a failover test (FOT), I went back in to select another checkpoint, and this time, the older checkpoints were gone (from over an hour ago). Selecting the oldest checkpoint at this time, allowed me to run a successful FOT because it was within range of the journal history setting. Lesson learned here – note to self: give Zerto a minute to figure things out, you just disconnected the brain from the spine!

Updated Checkpoints within Journal History Setting

Running a failover test to validate successful usage of checkpoints after ZVM outage:

File Server FOT in progress, validating fonts folder made it over to recovery site.

And… a recovery report to prove it:

Recovery Report - Successful FOT

Summary and Next Steps

So in summary, Zerto is self-healing and can recover from a ZVM being down for a period of time. That said, there are some things to watch out for, which include known what your configured journal setting is, and how a ZVM being down longer than the configured history setting affects your ability to recover.

You can still recover, however, you will start losing older checkpoints as time goes on while the ZVM is down. This is because of the first-in-first-out (FIFO) nature of how the journal works. You will still have the replica disks and journal checkpoints committing to it as time goes on, so losing history doesn’t mean you’re lost, you will just end up breaching your SLA for history, which will re-build over time as soon as the ZVM is back up.

As a best practice, it is recommended you have a ZVM in each of your protected sites, and in each of your recovery sites for full resilience. Because after all, if you lose one of the ZVMs, you will need at least either the protected or recovery site ZVM available to perform a recovery. The case is different if you have a single ZVM. If you must have a single ZVM, put it into the recovery site, and not on the protected site, because chances are, your protected site is what you’re accounting for going down in any planned or unplanned event. It makes most sense to have the single ZVM in the recovery site.

In the next article, I’ll be exploring this very example of a single ZVM and how that going down affects your resiliency. I’ll also be testing some ways to potentially protect that single ZVM in the event it is lost.

Thanks for reading! Please comment and share, because I’d like to hear your thoughts, and am also interested in hearing how other solutions handle similar outages.

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