11/17/2007
Data Test Program (dt)
36
Large Capacity Disk Testing
nTEST DESCRIPTION:  This test shows a method to verify large TB sized disks without doing I/O to the full capacity.  A number of options are used, here are the key ones:
uslices=16 to divide the capacity into 16 sections, each with their own process
uaios=4 to queue 16 requests per process for improved performance.
ustep=4g to seek after every record, thereby avoid writing every block.
uiodir=reverse to start at the end of sections then work forward.
uother options are left as an exercise to the reader! J
n
ushaix11# dt                              \
u         of=/dev/rhdisk10                \
u         slices=16                       \
u         step=4g                         \
u         disable=pstats                  \
u         aios=4                          \
u         oncerr=abort                    \
u         min=b                           \
u         max=256k                        \
u         incr=var                        \
u         align=rotate                    \
u         pattern=iot                     \
u         iodir=reverse                   \
u         prefix='%d@%h'                  \
u         alarm=5s                        \
u         noprogt=10s                     \
u         runtime=1h