SanDisk Upgrades FlashSoft Cache
- Support for multiple SSDs of mixed sizes and types
- Concatenation of two or more SSDs into a single caching volume
- SSD mirroring for “Safe Write-Back” caching
- A maximum cache size increase from 1TB to 2TB
- 2,048 accelerated objects can be stored in each cache, up from the earlier release’s 255
The company prides itself in the ease with which the software and a server-side SSD can be added to a system without otherwise changing its storage architecture.
With the “Safe Write Back” feature the FlashSoft software has been upgraded so that its existing write-back caching option will now support data mirroring, posting all writes to two identical SSDs to protect against problems caused by an SSD failure. If one of the two SSDs fails the program will automatically save the modified data from the other SSD into shared storage and change the caching policy to write-through mode until the failed SSD has been replaced. The server is not impacted except for the slowdown caused by moving to a write through policy.
One key benefit that SanDisk quietly points out is that server-side caching reduces network traffic, allowing data centers to tie larger clusters to their SANs. Overall this reduces data center costs by slowing the rate at which new SANs must be deployed.
FlashSoft has been conservatively designed to avoid consuming much in the way of system resources. The program requires 140MB of system memory and 2-4% of CPU utilization to manage the cache. In return the company claims that OLAP, OLTP, VMware, and databases operate up to five times as fast and enterprise applications can support up to three times as many users or virtual machines.
This upgraded software operates on Windows Server and Linux operating systems. A similar VMware revision was introduced in April. The software operates on any SSD (SATA, SAS, or PCIe) from any supplier.
This product comes in three flavors to support different environments:
- FlashSoft 3.2 for Windows Server ($3,000)
- FlashSoft 3.2 for Linux ($3,500)
- FlashSoft 3.1 for VMware vSphere ($3,900)
Caching is one of The SSD Guy’s favorite technologies, since I wrote a CPU cache book in the 1990s. It’s heartening to see this well-understood technology being used to help manage the new flash layer that is becoming so prevalent in computing systems.