CASL Architecture – Sunstar Company, Inc.

Nimble Storage solutions are built on its patented Cache Accelerated Sequential Layout (CASL™) architecture. CASL leverages the unique properties of flash and disk to deliver high performance and capacity – all within a dramatically small footprint.

Flexible Flash Scaling
Flexibly scale flash to satisfy the changing performance demands of today’s business-critical applications.
Dynamic Flash-Based Read Caching
CASL caches “hot” active data onto SSD in real time—without the need to set complex policies. This way it can instantly respond to read requests—as much as 10X faster than traditional bolt-on or tiered approach to flash.
Write-Optimized Data Layout:
CASL collects or coalesces random writes, compresses them, and writes them sequentially to disks. This results in write operations that are as much as 100x faster than traditional disk-based storage.
Inline Compression
CASL compresses data as it is written to the array with no performance impact. It takes advantage of efficient variable block compression and multicore processors. A recent measurement of our installed base shows average compression rates from 30 to 75 percent for a variety of workloads.
Scale-to-Fit Flexibility
CASL allows for the non-disruptive and independent scaling of performance and capacity. This is accomplished by either upgrading the storage controller (compute) for higher throughput, moving to larger flash SSD (cache) to accommodate more active data, or by adding storage shelves to boost capacity. This flexible scaling eliminates the need for disruptive forklift upgrades.
Scale Out
Scale capacity and performance beyond the physical limitations of a single array by seamlessly clustering any combination of Nimble Storage hybrid arrays. Eliminate capacity silos and performance hotspots, and easily manage all hardware resources across the cluster as a single storage entity.
Snapshots and Integrated Data Protection
CASL can take thousands of point-in-time instant snapshots of volumes by creating a copy of the volumes’ indices. Any updates to existing data or new data written to a volume are redirected to free space (optimized by CASL’s unique data layout). This means there is no performance impact due to snapshots and snapshots take little incremental space as only changes are maintained. This also simplifies restoring snapshots, as no data needs to be copied.
Efficient Replication
Nimble Storage efficiently replicates data to another array by transferring compressed, block-level changes only. These remote copies can be made active if the primary array becomes unavailable. This makes deploying disaster data recovery easy and affordable – especially over a WAN to a remote array where bandwidth is limited.
Zero-Copy Clones
Nimble Storage arrays can create snapshot-based read/writeable clones of existing volumes instantly. These clones benefit from fast read and write performance, making them ideal for demanding applications such as VDI or test/development.