Server virtualization is quickly becoming a standard technology in many data centers today. While VMware augments hardware utilization significantly through the use of server virtualization, VMware’s Virtual Infrastructure (ESX) 3 also introduces new issues concerning the backup and recovery of virtual environments.
It is important to remember that it is just as critical to protect data created and utilized in virtual machines as it is to protect the data that is located in a single physical machine. This paper describes several approaches that can be used to back up VMware ESX Server 3.x and its underlying components using Symantec Backup Exec 12.5 for Windows Servers and the Backup Exec Agent for VMware Virtual Infrastructure (AVVI). This paper also discusses the relative advantages and disadvantages of each method.
VMware Virtual Infrastructure 3 backup and recovery challenges
As server consolidation continues to accelerate, placing larger and larger numbers of VMware “guest” virtual machines in a single virtualized environment, planning backup, restore, and disaster recovery of the virtual environment is becoming an essential requirement of managing your virtual infrastructure. VMware Virtual Infrastructure 3 (VI 3) has quickly become an industry standard for organizations that want to virtualize their IT environments.
Companies are becoming dependent on efficient backup and quick recovery of their virtual systems—and the host systems they run on—to maintain business productivity and gain the cost savings that server virtualization delivers. This includes not only the guest virtual machines but also the applications that have been installed on them, such as Microsoft® Exchange®, SQL, and SharePoint Server. A lost ESX Server could impact multiple departments’ productivity for up to several hours, or even days, as the IT administrator struggles to recover the virtual environment and the individual guest virtual machines.
Administrators who are looking to protect their VMware environment quickly come to understand the frustration and time involved with backup technologies that are not built specifically for protection of virtual environments. Administrators and companies who have not had the experience of recovering a guest virtual machine using basic backup and recovery tools will face several limitations in recovering their data with older backup tools that were designed only for physical systems, including the need to:
- Install a backup agent inside of each guest virtual machine—or directly on the ESX Server
- Perform a time-consuming recovery of the entire guest virtual machine to recover a single file
- Perform separate backups for system-level and individual file–level recoveries
- Take guest virtual machines offline during backup in order to protect them completely
- Ensure that applications running inside the guest virtual machines can be recovered
- Use separate backup products for physical and virtual machines
Traditionally, these problems have been overcome through the use of VMware utilities that allow third-party backup software to perform backups within the ESX Service Console of live guest virtual machines. Unfortunately, performing live or “hot” backups of guest virtual machines using these utilities can require the use of scripts and Linux-based tools that usually require Linux scripting experience.
Additionally, these types of backups on the ESX Server can place an additional performance load on the entire ESX Server during backup, affecting all guest virtual machines on that ESX Server as well as all of the users connected to those guest virtual machines. Performing a hot backup can be difficult or impossible to manage manually. In addition, it is only cost-effective if it is both centralized and usable by the staff who need it.
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