Kansas City ExaGrid
Product Architecture
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.”
Fastest Backup/Shortest Backup Window
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.
Fastest Restores, Recoveries, VM boots and Tape Copies
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.
Scalability: Fixed length Backup Window and Data Growth
Data Deduplication
ExaGrid looked at the first generation, traditional approaches and saw that all vendors had used block-level deduplication. This traditional method splits data into 4KB to 10KB groups of bytes called blocks. The size of the block is variable length to improve matches. The challenge is that for every 10TB of backup data, the tracking table or hash table has one billion blocks. The hash table grows so large that it needs to be housed in a single front-end controller with additional disk shelves, often called “scale-up.” As a result, only capacity is added as data grows and since no additional bandwidth or processing resources are added, the backup window grows in length as data volumes increase. At some point, the backup window becomes too long and a new front-end controller is required, called a “forklift upgrade.” This is disruptive and expensive.
ExaGrid also saw approaches that used byte-level deduplication. Although this method allows for GRID scalability, called “scale-out,” it requires an understanding of the format of every backup application, which limits the list of supported backup applications.
ExaGrid took a third and more innovative path. ExaGrid uses zone-level deduplication, which breaks data into larger zones and then compares at the byte level. This approach allows for the best of both worlds. First, the tracking table is 1,000th the size of the block-level approach and allows for full appliances in a GRID, called “scale-out.” As data grows, all resources are added: processor, memory, and bandwidth as well as disk. If data doubles, triples, quadruples, etc., then ExaGrid doubles, triples, and quadruples the processor, memory, bandwidth, and disk. As data grows, the backup window stays at a fixed length. Second, the zone approach is backup application agnostic, allowing ExaGrid to support virtually any backup application.
In summary, block-level deduplication drives a scale-up architecture that only adds disk as data grows, which expands the backup window; byte-level deduplication allows for scalability but limits backup application support; however, ExaGrid zone-level deduplication allows for full server appliances in a GRID – ascale-out approach – as well as a wide range of backup application support.
ExaGrid continues to innovate to fix backup…forever!