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Storage virtualization makes DR easier
When you implement server virtualization, the virtual disk for every server is contained in a file. With vSphere, it’s a VMDK file; for Hyper-V the file is called a VHD (or VHDX with Hyper-V 3.0). This is one form of storage virtualization and part of what makes these VMs so portable. It also offers many benefits that make DR easy. Some of the ways
- Features like VMware’s Storage vMotion can move running virtual machine disk files from one datastore to another to prevent localized disasters.
- Virtual machine disk files can be easily backed up and restored to another host.
- Changed blocks of virtual machine disks can be easily tracked so that backup and restore times can be drastically shortened.
- Similarly, those changed blocks can be easily tracked and then replicated to an off-site repository, both for off-site backup and for quick restore to DR servers.
- As with server virtualization, identical SAN storage is no longer required at the DR site as the VM disk files can be stored on whatever shared storage is available.
Many advanced third-party storage virtualization tools take advantage of the storage virtualization tools built into the hypervisor. For example, third-party products can use the VMware API for Data Protection to access only the changed blocks of a VM disk file, and back up or replicate those blocks to an off-site location.
In most cases these virtual machine disk files are stored on a local virtualization host or shared storage. While virtualizing storage is a huge benefit, there are other storage virtualization offerings you can choose that offer other benefits for DR.
For example, the vSphere Storage Appliance (VSA) is an affordable NAS that uses extra local storage on ESXi hosts to store VMs but can still offer high availability and certified virtual storage for virtual machines.
The StarWind Software iSCSI SAN runs on top of the Windows OS and offers high availability and data replication to another virtual SAN at the backup site. The StarWind virtual SAN is a great product for storing Hyper-V and vSphere VMs, offers advanced features and helps you avoid having to buy an expensive shared storage array. FalconStor’s Network Storage Server is a similar product that offers DR benefits for virtual infrastructures. Both companies offer free trial versions.
VDI aids DR
Users will want to get back to work quickly after a disruption. Initial recovery efforts typically focus on getting servers and storage up and running again, but what about those hundreds or thousands of desktop and laptops PCs? To get the business back to normal (or near normal) operations, it isn’t enough to just get the servers back online.
Virtual desktop infrastructure (VDI) can get end users working again quickly. By virtualizing desktops with products like Citrix XenDesktop or VMware View, you can offer a consistent, reliable, scalable, secure and easily maintained desktop pool for end users to access from nearly any device they have when there’s a disaster. Better yet, why wait for a disaster? Reap the benefits of desktop virtualization now and be ready if disaster strikes by converting your company’s physical desktops/laptops to virtualized desktops.
BIO: David Davis has been awarded the VMware vExpert award three times. He has spoken at major conferences and authored hundreds of articles. You can follow David on Twitter @davidmdavis or connect with David on LinkedIn.
This was first published in October 2012