Category Archives: Storage

Storage Replica: What's new in Windows Server 2019 and the management with Windows Admin Center

Storage Replica, in Microsoft home, is a technology introduced in Windows Server 2016 that you use to replicate, synchronously or asynchronously, volumes between servers or clusters, for disaster recovery purposes. This technology also allows you to create stretch failover cluster with nodes spread over two different site, keeping in sync the storage. This article will present the news, regarding Storage Replica, that will be introduced in Windows Server 2019 and you will be shown how to enable Storage Replica by using the new management tool Windows Admin Center.

 

What's new in Storage Replica in Windows Server 2019

In Windows Server 2016 there is the possibility of using Storage Replica only if you use the Datacenter Edition as operating system version, while in Windows Server 2019 there will be the option to enable Storage Replica also adopting the Standard Edition, but right now, with the following limitations:

  • You can replicate a single volume instead of an unlimited number of volumes.
  • The maximum size of the replicated volume should not exceed 2 TB.
  • The volume in replica can have only one partnership, instead of an unlimited number of partners.

By adopting a new Log format used by Storage Replica (Log v 1.1), imported performance improvements are introduced regarding throughput and latency. You can benefit from these improvements if all systems involved in the replication process will be Windows Server 2019 and will be especially noticeable on all-flash arrays and on Storage Spaces Direct cluster (S2D).

To validate the effectiveness of the replication process, is introduces the ability to perform a Test Failover. Through this new feature it is possible to mount a writable snapshots of the replicated storage. To perform this operation, for testing purposes or backup, you must have a volume, not involved in replication, on the destination server. Testing Failover has no impact on the replication process, which will continue to ensure the protection of the data and the changes to the snapshot will remain circumscribed to the test volume. Upon completion of testing it is appropriate to conduct a discard of the snapshot.

Storage Replica in Windows Admin Center

Windows Admin Center, also known as Project Honolulu, enables via an HTML5-based web console, to manage the infrastructure in a centralized way.

Through Windows Admin Center, you can install on the servers the Storage Replica feature and the related PowerShell module.

Figure 1 - Add the Storage Replica feature from Windows Admin Center

Figure 2 - Confirm the installation of Storage Replica and its dependencies

Figure 3 - Notification that the installation was successful

After the installation, the server requires a restart.

At this point you can configure, through Windows Admin Center, a new partnership of replica. The same thing could be accomplished using the Windows Powershell cmdlet New-SRPartnership.

Figure 4 - Adding new Storage Replica partnership between two replication Groups

Figure 5 - Settings required for the configuration of the Partnership

Windows Admin Center reports, at the end of the configuration, the details of the partnership.

Figure 6 - Details about the replication partnership

In addition, you can manage the replication status (suspend \ resume), switch the direction of synchronization and modify the configurations (add \ remove the replica volumes and settings of the partnership).

Figure 7 - Switch the replication direction

Figure 8 - Changing the partnership settings

Conclusions

Windows Server 2019 will introduce significant changes in Storage Replica service that, In addition to evolve it in terms of performance and effectiveness, will make it even more accessible. The whole is enriched by the possibilities offered by Windows Admin Center to easily, quickly and completely manage Storage Replica. Microsoft is making significant investments in storage and the results are obvious and tangible. For those wishing to test the latest new features about Windows Server 2019 can participate in the program Windows Insider.

 

 

Windows Server 2016: Introduction to Hyper-V VHD Set

In Windows Server 2016 a cool new feature was introduced in Hyper-V, codenamed VHD Set. This is a new way of creating virtual disks that need to be shared among multiple virtual machines, useful for implementing guest cluster. In this article you will learn the characteristics of VHD Set, you will learn how to implement them at best and how to effectively address migration scenarios.

Features

The ability to share virtual disks across multiple virtual machines is required for clustered configurations guest requiring shared storage and to avoid having to configure access to storage via for example virtual HBA or through the use of iSCSI Protocol.

Figure 1 – VHD Set

In the Hyper-V this feature was introduced with Windows Server 2012 R2 technology called Shared VHDX, which has the following important limitations that often prevent the use in production environment:

  • Back up the Shared VHDX should occur with specific agents and host based backup is not supported
  • Hyper-V replication scenarios are not supported
  • The resize online of Shared VHDX is not covered

With Hyper-V in Windows Server 2016 This feature was revolutionized with the introduction of the VHD Set instead of Shared VHDX which removes the limitations listed above making it a mature technology and reliable even for production environments. In fact the virtual machines that are configured to access the VHD Set you can protect them by host based backup, without having to install agents on guest machines. In this case we recommend a check to determine whether the backup solution supports this configuration. Also the discs in the VHD format Set support online resizing, without the need to stop the guest cluster configured to access it. Even the Hyper-V replication supports VHD format disks Set allowing you to implement disaster recovery scenarios for guest cluster configurations.

At the moment the only limitations in using VHDs Set are given by non-support for creating virtual machine checkpoint that access and the inability to perform a live migration of virtual machines with VHD storage Set. Microsoft's goal for the future is anyway to make virtual machines configured with VHD joint Set all other functionality.

Requirements for using VHD Set

The VHD Set format is supported only for guest operating systems Windows Server 2016. You can also configure guest cluster where virtual machines are accessing shared virtual disks you must fall into one of the following scenarios:

  • Hyper-V failover cluster with all files of VMs, including in the VHD Set format , residing on a Cluster Shared Volumes (CSV).
  • Hyper-V failover cluster that has as a storage location for VHD Set a SMB share 3.0 output from one Scale Out File Server (SOFS).

Figure 2 – Supported scenarios for using shared virtual disks

How To Create VHD Set

Creating virtual disks in the VHD Set format can be made either with a Graphical User Interface (GUI) that using Powershell. To create them via GUI simply open Hyper-V Manager and from the Actions Select New, Hard Drive. Among the possible formats will also be VHD Set as shown in the following figure:

Figure 3 – Selecting the virtual disk format in the creation wizard

Continuing with the Wizard, you can specify whether the disk should be classified as Fixed rather than Dynamic, the name, the location and its size if you choose to create a new blank disk. The same thing can also be done using Powershell cmdlet New-VHD, specifying as an extension of the virtual disk the new extension .vhds, as shown in the following example:

Figure 4 – Example of creating a disc in the VHD format Set using Powershell

Creating a disk in VHD Set format creates the following files in the specified location:

Figure 5 – Files generated by creating a disc in VHD format Set

The file with extension .avhdx contains data and can be fixed or dynamic depending on the choice made when creating, while the file .vhds contains the metadata required to coordinate access by different guest cluster nodes.

Virtual machine configuration with VHD Set

In order to add the drives in VHD Set format to virtual machines by modifying the properties and configure properly connecting SCSI controller:

Figure 6 – Addition of the Shared Drive in the properties of the VM

Next you must select the location of the file:

Figure 7 – Configuring the location of the shared drive

The same thing you will have to do it for all the virtual machines that will make up the guest cluster. After configuring the shared storage, that adds to the virtual machines the disks in VHS Set format, you can continue to configure the guest environment cluster according to the standard procedure for creating a cluster is described in Microsoft's official documentation.

Converting Shared VHDX in VHD Set

In Hyper-V infrastructure upgrade scenarios from Windows Server 2012 R2 to Windows Server 2016, may have to deal with the migration of Shared VHDX in VHD Set to take advantage of all the benefits in the new technology of virtual disk sharing. Moving to Windows Server 2016 there is no automatic update of Shared VHDX in VHD Set and is not prevented from continuing to use the shared disks in Shared VHDX format in Windows Server 2016. In order to migrate the Shared VHDX in VHD Set format you need to follow the steps manual:

  • Shut down all virtual machines connected to the Shared VHDX you intend to migrate.
  • Disconnect the Shared VHDX from all VMs using Powershell cmdlet Remove-VMHardDiskDrive or by using Hyper-V Manager.
  • Start converting the Shared VHDX in VHD format Sets via Powershell cmdlet Convert-VHD
  • Connect the disk you just converted to the VHD format Set to all VMs using Powershell cmdlet Add-VMHardDiskDrive or by using Hyper-V Manager.
  • Turn on virtual machines connected to VHD Set.

When using disks in VHD format sets can be useful the following Powershell cmdlets:

  • Get-VHDSet: useful for displaying various information about the disk in the VHD Set format, including a list of any checkpoint.
  • Optimize-VHDSet: needed to optimize space allocation used by the disk in the VHD Set format.

Conclusions

In Windows Server 2016 the introduction of VHD Set in Hyper-V enables you to easily implement architectures guest cluster without using storage sharing technologies that require heavy and complex configurations. Were also removed most of the restrictions regarding the methodology of sharing of virtual disks, present in the previous version of Hyper-V, making VHD Set a mature technology, reliable and therefore can also be used in production environments.