DuraWriteTM Virtual Capacity
• Dramatically lowers the cost per GB of delivered capacity
• Increases the available storage capacity for typical data
• Most beneficial for low-entropy data workloads
The cost of data storage is a critical concern when evaluating the implementation
of flash-based storage in compute applications. While SSDs offer numerous performance
benefits, the cost per GB of flash memory is still considered high compared to traditional
data storage alternatives. LSI® SandForce® DuraWrite™ Virtual Capacity (DVC) is
a unique feature of LSI SandForce flash controllers that extends the available storage
space beyond the physical capacity of the underlying flash memory.
LSI SandForce Solution = More GB/$
LSI SandForce DVC is enabled by LSI DuraWrite™ architecture, a proprietary and unique
data reduction technology. The free space created by this architecture is normally
used as additional over provisioning in an SSD. When combined with DVC, this extra
capacity is instead returned to the user as additional storage space. DVC results
in an increased storage capacity for the same physical flash memory, thereby reducing
the cost per GB of delivered capacity to the user. With typical database applications,
internal testing has shown that DVC can be used to more than triple the capacity
for storing user data.
Free Space Monitoring
The total increased capacity provided by DVC will vary based on the compressibility
of the data itself. Traditional operating systems do not comprehend storage devices
that change capacity over time. For this reason, DVC provides a dedicated SMART
attribute to enable applications to control and monitor the remaining free physical
space and manage the amount of valid data to ensure proper performance and behavior.
For customers who can modify or create their own storage operating system, this
monitoring and control capability can be completely automated.
DVC offers greater advantages in applications with lower entropy data workloads,
such as the boot drives and caching drives found in many HyperScale Datacenter and
Cloud Computing Servers. Applications with higher entropy data workloads still benefit
from this technology, but the capacity increase would not be as high.
Specifications and Availability
• Virtual capacity reporting via IDENTIFY DEVICE
• Free space monitoring via SMART attribute
• Available with SF-2000 flash controllers configured with up to 256GB of raw