Lab Validation:
SanDisk FlashSoft
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© 2012 by The Enterprise Strategy Group, Inc. All Rights Reserved.
SanDisk FlashSoft for VMware vSphere
FlashSoft for VMware vSphere is a software module designed to accelerate application performance in VMware
guest machines on a physical server. FlashSoft increases the performance of I/O operations in VMware
environments by creating a software-based read cache using virtualized SSD capacity; SSD is dynamically allocated
to accelerate virtual disks (VMDKs) as needed. This increase in I/O performance also enables greater virtual
machine density. No agents are used in the guest OS, and the software requires less than 10MB of disk space to
install and less than 140MB of system memory at runtime. Because FlashSoft is software-based, the cache can
consist of any SSD memory device connected via PCIe, SAS, or SATA interfaces, and SSDs can reside in the server or
outside of it. FlashSoft can accelerate data in DAS, SAN, or NAS-based data stores without restriction.
FlashSoft is installed quickly using the standard vSphere Installation Bundle (VIB), and it runs as a block-level file
device switch (FDS) loadable module in the ESX kernel (see Figure 2). This software module requires no changes to
the storage configuration, and it operates in the ESX cluster without restrictions. FlashSoft for VMware vSphere is
managed through a vCenter console plug-in and supports all native VMware functionality including high availability,
vMotion, Storage vMotion, snapshots, clones, linked clones, and VDI. It can be installed in some or all servers in a
cluster, and it can accelerate the VMDKs of any servers in which it is installed. Acceleration can selectively be
started and stopped on any VMDK individually.
Figure 2. SanDisk FlashSoft Software
FlashSoft accelerates VMDKs on VMFS or NFS storage. When FlashSoft is installed on servers running multiple
virtual machines, the cache space on the SSD is shared dynamically among the VMs. During read activity, all data
passes through the FlashSoft driver in the storage stack; FlashSoft identifies the most frequently used data and
caches it on SSD. In many cases, while only a small percentage of a total data set is “hot,” it can account for 70% to
80% of server I/O. As a result, implementing a relatively small SSD-based cache for frequently accessed data can
provide dramatic performance improvements and eliminate the need to store all of an application’s data on SSD.
