I have the feeling I should call this post ‘part 1’ as I’m writing things as I discover new features and how to use them.
In 11G release 2 ASMCMD has a iostat feature that allows you to list the reads and writes per disk (either as I/O operation or bytes)
iostat [-et][–io] [–suppressheader] [–region] [-G diskgroup] [interval]
-e display error statistics (write/read)
-t display time statistics giving the total I/O time in hundredths of a second (requires TIMED_STATISTICS to be true)
interval – repeat the command every X seconds
As with most iostat commands, the first run in an interval is total stats up to now, and subsequent intervals cover the time since previous report.
ASMCMD> iostat -t -G data_upper 5 Group_Name Dsk_Name Reads Writes Read_Time Write_Time DATA_UPPER DATA_DM01_CD_00_ED2HCELL12 368823115776 398765133824 15652.064264 115609.999195 DATA_UPPER DATA_DM01_CD_00_ED2HCELL13 360830513152 399665251328 15293.415546 108496.371997 Group_Name Dsk_Name Reads Writes Read_Time Write_Time DATA_UPPER DATA_DM01_CD_00_ED2HCELL12 0.00 0.00 0.00 0.00 DATA_UPPER DATA_DM01_CD_00_ED2HCELL13 0.00 6553.60 0.00 0.00
This information is extracted from the V$ASM_DISK_IOSTAT dynamic performance view.