Data Sheet
Fusion-io directCache
Fusion’s directCache transforms ioMemory into a transparent, auto-tiering, acceleration device to cache any block-based storage medium whether it is a disk array, SAN, direct attached storage or iSCSI target. directCache places the caching software in the server to deliver lower cache latency. With directCache, Fusion-io customers can have Terabytes of cache acceleration at their fingertips to speed performance of any backing store. This add-on module for ioSphere integrates tightly with Fusion’s Virtual Storage Layer, a flash-optimized OS subsystem, to deliver immediate application workload performance improvements.
directCache Benefits
- Transparently accelerate existing storage volumes. directCache caches the most frequently accessed blocks for instant performance gains
- Seamless integration with existing block storage devices. directCache eliminates the need for costly and complex tiering systems based on Fibre Channel or SAS disks
-
Minimum disruption with maximum benefit. directCache requires no changes to the storage
infrastructure, preserving existing configurations - Immediate performance improvements. Requests coming from NAND flash memory at the server-level can be hundreds of times faster than those from disk-based solutions
- Reduce the need to configure disks for IOPS. directCache delivers up to hundreds of thousands of IOPS, eliminating the need to overprovision drives, and cutting cost and complexity
- Maximum performance from NAND flash memory. ioMemory with directCache removes the overhead of legacy storage protocols by integrating directly with a native PCIe implementation
Features
- Support for direct attached, SAN-attached, and appliance-attached storage
- Transparent installation. Host operating systems continue to see block devices as-is
- Data security. directCache’s write through caching keeps data as safe as your backing store
- Statistics to monitor cache hits and performance
Technical Detail
- Accelerate any OS visible block storage volume
- Write through cache mode
- Replacement based on recency
- Direct integration with Virtual Storage Layer (VSL)
- Fully associative
- Individual storage sector granularity
- Avoids meta-data double writing on fault load
- Maintains 100% cache capacity utilization
- Avoids saturated write performance loss and wear
- Full performance of backing-store even with no cache hits
- Adapts to current health and usable capacity of the ioMemory
directCache Diagram

Product Features
|
Product type |
Add-on software module for ioMemory VSL |
|
Cache type |
Fully associative cache |
|
Cache mode |
Write-through |
|
Minimum cacheable block size |
512B |
|
Max cache instances per host |
Unlimited |
|
Additional CPU & RAM overhead |
No noticeable increase over the ioMemory VSL requirements |
|
Product architecture |
Independent Linux kernel module, Window volume/disk filter driver |
|
Management |
CLI utilities to bind, unbind, and provide status |
|
Protection modes |
Optional partition table obfuscation |
|
Power loss protection |
Yes |
System Requirements
|
ioMemory VSL driver |
directCache requires a 2.3.0 version of the ioMemory VSL or later |
|
Compatible cache devices |
All ioDrive, ioDrive Duo, and ioDrive Octal products are compatible with directCache except ioDrives with a v6 or earlier adapter |
|
Operating systems |
64-bit Microsoft Server 2003/2008/2008 R2/Vista/Win7, RHEL 5/6, SLES 11 |
|
Supported backing store types |
Disk, disk partition, hardware RAID volume, software RAID volume, iSCSI LUN, Fibre Chennel Lun |
For More Information:
Visit http://www.fusionio.com
To speak with a Fusion-io specialist in the U.S. call: +1 (801) 424 5500
To speak with a Fusion-io specialist outside the U.S.: http://fusionio.com/company/contact