Defining Storage Virtualization
The SNIA Shared Storage Model
Application layer
Applications
Types of Virtualization
File/record layer
File system Database
File system
(FS) (DBMS)
n
i
o
Block Aggregation layer
at
Host-based Host
e
g
Switch or
ggr
Network
Appliance based
k a
Subsystem-based Device
l
oc
B
Disk/Tape Storage devices
If we go back to the SNIA Shared Storage Model we have an application layer.
Our application will either issue a record request or a file I/O request. Our file
system or database will take that file I/O or record I/O request and convert it to
a block I/O request.
The block I/O request will then come down through our block
aggregation layer. It’s the block I/O request from the file system that will
feed through our virtualization layer. Our virtualization layer is in our
block aggregation layer.
File system virtualization could be software based or the new hardware
components that can read multiple file systems from NAS appliances and then
make it look like one big file system.