Running I/O to LUNs on Windows with vdbench can be a bit tricky since the syntax is not terribly intuitive. This has more to do with Windows than vdbench. The following two examples show how to dereference these LUNs for both raw and filesystem I/O.

Raw I/O to LUNs

• Open Server Manager
• Go to Tools -> Computer Management -> Storage
• Right-click on Disk Management and select Rescan Disks
• Right-click on each Disk (newly discovered LUN) and select Online/Initialize the Disk

All LUNs should be discovered on Windows and set to Online. It is very important that you do not build any filesystem on top of these LUNs if you wish to do raw I/O. A VDBench workload profile should have each LUN dereferenced using the format \\.\PhysicalDriveX. The following sample demonstrates this format:

data_errors=(50,60),validate=yes
                         
sd=sd1,lun=\\.\PhysicalDrive2,size=1g
sd=sd2,lun=\\.\PhysicalDrive3,size=1g
sd=sd3,lun=\\.\PhysicalDrive4,size=1g
sd=sd4,lun=\\.\PhysicalDrive5,size=1g
                         
wd=wd1,sd=sd*,xfersize=1048576,readpct=50
rd=run1,wd=wd1,iorate=max,elapsed=999h,interval=1
                        

Filesystem (NTFS) I/O

• Open Server Manager
• Go to Tools -> Computer Management -> Storage
• Right-click on Disk Management and select Rescan Disks
• Right-click on each Disk (newly discovered LUN) and select Online/Initialize the Disk
• Right-click on each Disk (newly discovered LUN) and create a new Simple Volume. It's recommended to use NTFS.

A VDBench workload profile should have each LUN dereferenced using the drive letter assigned when the simple volume was created. You'll also want to specify a directory after the driver letter for vdbench to store its files. The following sample demonstrates this format:

create_anchors=yes
data_errors=(50,60),validate=yes
                        
fsd=fsd1,anchor=D:\vdbench,depth=2,width=2,files=20,size=100m
fsd=fsd2,anchor=E:\vdbench,depth=2,width=2,files=20,size=100m
fsd=fsd3,anchor=F:\vdbench,depth=2,width=2,files=20,size=100m
fsd=fsd4,anchor=G:\vdbench,depth=2,width=2,files=20,size=100m
                        
fwd=fwd1,fsd=fsd*,operation=read,xfersize=1m,fileio=sequential,fileselect=random,threads=32
fwd=fwd2,fsd=fsd*,operation=write,xfersize=1m,fileio=sequential,fileselect=random,threads=32
                    
rd=rd1,fwd=fwd*,fwdrate=max,format=yes,elapsed=999h,interval=1