11-09-2010 12:36 PM
There are a number of methods for protecting VMware servers, and they differ depending on which VMware hypervisor version you’re using. The vStorage API for Data Protection has dramatically streamlined VMware virtual server backup and recovery processes. vStorage runs in vSphere 4.x environments only and many organizations are moving to vSphere in order to take advantage of the significant benefits provided by vStorage.
However, it will take time to migrate everything to the new platform. In many cases, customers will need to protect VMware Virtual Infrastructure 3.x and vSphere 4.x environments simultaneously for some time. (For a complete overview of VMware infrastructure products, visit the VMware site.)
HP Data Protector software is tightly integrated with the VMware infrastructure and provides a variety of methods for protecting VMware virtual machines to meet your own unique RTO, RPO, and other priorities. HP Data Protector provides auto-discovery to ensure that all virtual servers are protected, and provides support for any VMware hypervisor version. All VMware backup and recovery methods can be executed through the Data Protector console, which allows administrators to simplify data protection processes by using one backup product for VMware, other hypervisors, and physical servers.
All of the following can be managed via the HP Data Protector console:
- Traditional online backup agents inside the virtual machine
- Server-based snapshots
- VMware Consolidated Backup (VCB)
- VMware vStorage API for Data Protection (VADP)
- HP Data Protector array-based snapshots
Traditional online backup agents inside the virtual machine
Installing an online agent in each virtual machine, just as you would in the physical world, is probably the easiest way to back up VMware servers. It’s the method with which backup administrators are most familiar.
This approach delivers consistent backups, so data is synched with the application upon restore, as the HP Data Protector backup agent communicates directly with the application. However, with all the other virtual machines on that physical host competing for resources, server performance can be impacted.
Restoring data from a virtual machine is no different to restoring data from a physical machine. The backup administrator browses for desired objects in the HP Data Protector console and retrieves information through a simple mouse click.
Server-based Snapshots with VMware ESX and ESXi Servers
VMware ESX Server allows for server-based snapshots, but there is no way to execute console-based snapshots with VMware ESXi Server which is based on a new slim 32-MB hypervisor with no place to install an online backup agent.
VMware has announced that ESX Server will be unavailable after vSphere 4.1. Meanwhile, for organizations that haven’t yet migrated to ESXi Server, IT staff using ESX Server are able to take snapshots of data on every virtual machine. Each snapshot is then stored on disk or can be moved to tape for recovery as needed. By installing HP Data Protector online agents within ESX Server, administrators can use the HP Data Protector console to automate execution of server-based snapshots.
But there are problems with this. ESX Server-based snapshots impact server performance and yield only crash-consistent data. For some classes of data, this is acceptable but it’s not an option for business- or mission-critical applications.
To perform a restore, the backup administrator simply browses for the desired snapshot image and restores the information to the virtual machine with a single mouse click. HP Data Protector then restarts the virtual machine to a particular point in time.
VMware Consolidated Backup (VCB) image- and file-level backups
VMware developed VCB to reduce the impact of virtual server backup on application and server performance. VCB is loaded on a dedicated server – or proxy host – from which you can run either an image- or file-level backup. The proxy host offloads the processing from the physical host, but leaves only crash-consistent data upon recovery.
VMware has announced that VCB will reach end of life with the next version of VMware vSphere, and users should instead leverage the VMware vStorage API for Data Protector (VADP). Meanwhile, many companies are continuing to use VCB. When they’re ready to migrate all of their virtual servers to the latest hypervisor, Data Protector will help. It simplifies migration by allowing IT staff to manage VCB-based backup and recovery processes, as well as backup and recovery for physical servers and other VMware hypervisor versions, all from one console.
VMware vStorage API for Data Protection (VADP) backups
VADP is a framework for vSphere to enable backup products. It fixes one of the key limitations of VCB – the problem of crash-consistent data – while also enabling backup products to better protect and recover VMware environments.
VADP ensures application-consistent backups of Windows virtual machines and Windows applications through support of Microsoft Volume Shadow Copy Services (VSS). It also allows backup software to back up and restore incremental, differential, and full-image backups. And VADP resolves the server performance issue by offloading backup to the backup server. VADP also protects Linux machines. However, since VSS is a Microsoft invention, it can only achieve crash-consistent backups of Linux virtual servers.
When using VADP, a HP Data Protector backup agent is installed on the backup server. Data Protector automatically discovers VMware virtual machines to ensure all data is protected. To restore a backup, the administrator browses for the desired object in the HP Data Protector console, and restores with a single mouse click.
HP Data Protector Zero Downtime Backup and Instant Recovery
In a VMware environment, HP Data Protector’s Zero Downtime Backup (ZDB) agent is the only way to achieve everything – eliminate any server performance overhead, guarantee application data consistency, and recover data to the second without scripting – all from a single console.
HP Data Protector ZDB utilizes array-based snapshots to move the processing load off the virtual machines and onto the array, where a copy of the data is created at very high speed. HP Data Protector then performs backup operations on the copy, rather than on the original data. This staged backup process allows you to keep your business applications online 24x7 without impacting server performance. The HP Data Protector ZDB agent is also application-aware, so it provides you with consistent backup in VMware environments where traditional backup methods (an online agent in a VM) or VADP are not being utilized. ZDB allows you to perform backups more frequently than once a night on an unlimited number of virtual machines and, in fact, eliminates your backup window to all day, every day. In addition, HP Data Protector maintains snapshots on the disk array for use by HP Data Protector Instant Recovery (IR).
For business- or mission-critical applications, your backup software must be able to automate the creation and recovery of snapshots on virtual servers. And, for some applications, the ability to recover to the minute – or even the second – between snapshots is crucial. HP Data Protector software can access application transaction logs (where all of the application’s transactions are recorded before they’ve been processed and/or written to data file) and fill in the data gaps between snapshots. HP Data Protector then synchronizes the application with the data, and restarts the application to the exact point in time you need. You simply enter the hour, minute and second into the Data Protector console.
In mission-critical environments, the ability to automate this process without utilizing a scripted or manual solution is critical. Both can leave room for errors and sap valuable time.
For more detailed information on Data Protector support for VMware environments, watch the HP Data Protector software webcast: Best Practices for Data Protection in a Virtual World. Or check out our blog on the HP Software & Solutions Data Protection Community for information on HP Data Protector support for Microsoft Hyper-V environments.
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