Why ExaGrid Versus Traditional Disk-based Backup Appliances

All IT departments want to back up to disk versus tape. Data deduplication greatly reduces the amount of disk required by only storing unique bytes or blocks from backup to backup. Over an average retention period, deduplication will use about 1/10th to 1/50th of the disk, depending on the mix of data types. On average, the deduplication ratio is 20:1.

All vendors need to offer data deduplication in order to reduce the amount of disk to lower the cost to be about the same as tape. However, how deduplication is implemented changes everything about backup.

The traditional approach deduplicates the backups inline during the backup process. Deduplication is a compute-intensive process and slows backups down, which results in a longer backup window. Some vendors put software on the backup servers in order to use additional compute to help keep up, but this steals compute from the backup environment.

Shortest Backup

In addition, if deduplication occurs inline, then all of the data on the disk is deduplicated and needs to be put back together, or “rehydrated,” for every request. Local restores, instant VM recoveries, audit copies, tape copies and all other requests take hours to days.

Fastest Restore & Recovery

Furthermore, these solutions employ a scale-up architecture with a front-end controller and disk shelves. As data grows, only disk shelves are added, which expands the backup window until the backup window becomes too long and the front-end controller needs to be replaced with a bigger, faster and more expensive front-end controller, called a “forklift upgrade.”

Fixed Backup Window

ExaGrid understands that deduplication is required, but how you implement it changes everything in backup. ExaGrid has a unique landing zone where backups can land straight to disk without any inline processing. Backups are fast and the backup window is short. Deduplication and offsite replication occur in parallel with the backups. Deduplication and replication never impede the backup process as they always are second order priority. ExaGrid calls this “adaptive deduplication.” Since backups write directly into the landing zone, the most recent backups are in their full undeduplicated form ready for any request. Local restores, instant VM recoveries, audit copies, tape copies, and all other requests do not require rehydration and are as fast disk. As an example, instant VM recoveries occur in seconds to minutes versus hours for the inline deduplication approach. ExaGrid provides full appliances (processor, memory, bandwidth, and disk) in a scale-out GRID. As data grows, all resources are added including additional landing zone, additional bandwidth, processor, and memory as well as disk capacity. The backup window stays fixed in length regardless of data growth, which eliminates expensive forklift upgrades. Unlike the inline, scale-up approach where you need to guess at which sized front-end controller is required, the ExaGrid approach allows you to simply pay as you grow by adding the appropriate sized appliances as your data grows. ExaGrid has 10 appliance models and any size appliance or any age appliance can be mixed and matched in a single GRID, which allows for IT departments to buy compute and capacity as they need it. This approach also eliminates product obsolescence.

ExaGrid’s approach takes the same rack space, same power and cooling, and is the same or lower price.

ExaGrid thought through data deduplication implementation and created an architecture that provides for the fastest backups, restores, recoveries and tape copies; fixed the backup window as data grows; and eliminated forklift upgrades and obsolescence, all while allowing IT staff to buy what they need as they need it. There is no downside and only upside. ExaGrid has taken the stress out of backup storage.