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The challenging aspect of using cloud-based backups for disaster recovery is the recovery. With bandwidth limited and possibly terabytes of data to be recovered, getting data restored back on-premises within defined RTOs can be challenging. Some cloud backup service providers offer an option to restore data to disks, which are then sent to the customer for local on-premises recovery. Another option is a large on-premises cache of recent backups that can be used for local restores.
“I firmly believe that backups need to be local and from there sent into the cloud; in other words, the backup in the cloud becomes your secondary off-site backup,” said Jim Avazpour, president at OS33 Inc.’s infrastructure division.
On the other hand, depending on the data to be restored, features like compression and, more importantly, data dedupe can make restores from data in the cloud to on-premises infrastructure a viable option. A case in point is Michigan-based Rockford Construction Co., which uses a StorSimple appliance for cloud-based protection of its Exchange and SharePoint infrastructures. “In case of a disaster, we’ll pull VMs [virtual machines] from the cloud; with StorSimple’s deduplication we pretty much have to only pull down one full VM copy and the differences for others,” said Shaun Partridge, vice president (VP) of IT at Rockford Construction.
CLOUD-BASED DR APPROACHES SIDE-BY-SIDE
Enlarge CLOUD-BASED DR APPROACHES SIDE-BY-SIDE diagram.
Back up to and restore to the cloud. In this approach, data isn’t restored back to on-premises infrastructure; instead it’s restored to virtual machines in the cloud. This requires both cloud storage and cloud compute resources, such as Amazon’s Elastic Compute Cloud (EC2). The restore can be done when a disaster is declared or on a continuous basis (pre-staged). Pre-staging DR VMs and keeping them relatively up-to-date through scheduled restores is crucial in cases where aggressive RTOs need to be met. Some cloud service providers facilitate bringing up cloud virtual machines as part of their DR offering. “Several cloud service providers use our products for secure deduped replication and to bring servers up virtually in the cloud,” said Chris Poelker, VP of enterprise solutions at FalconStor Software.
Replication to virtual machines in the cloud. For applications that require aggressive recovery time and recovery point objectives (RPOs), as well as application awareness, replication is the data movement option of choice. Replication to cloud virtual machines can be used to protect both cloud and on-premises production instances.
In other words, replication is suitable for both cloud-VM-to-cloud-VM and on-premises-to-cloud-VM data protection. Replication products are based on continuous data protection (CDP), such as CommVault Continuous Data Replicator, snapshots or object-based cloud storage such as EMC Atmos or the Hitachi Content Platform (HCP). “Cloud service provider Peak Web Hosting enables on-premises HCP instances to replicate to a Peak Web HCP instance instead of another on-premises HCP instance,” said Robert Primmer, senior technologist and senior director content services, Hitachi Data Systems.
New options, old fundamentals
The cloud greatly extends disaster recovery options, yields significant cost savings, and enables DR methods in small- and medium-sized businesses (SMBs) that were previously only possible in larger organizations. It does not, however, change the DR fundamentals of having to devise a solid disaster recovery plan, testing it periodically, and having users trained and prepared appropriately.
BIO: Jacob Gsoedl is a freelance writer and a corporate director for business systems. He can be reached at email@example.com.
This was first published in May 2011