I/O Resource Management and Instance Caging - Oracle Exadata Recipes: A Problem-Solution Approach - page 513

10. #max_conc_io=5 write_cache_hit_rate=94% iocost=55834574849ms
11. catidx=0 bitmap=0 CAT_HIGH
12. catidx=1 bitmap=0 CAT_MEDIUM
13. catidx=2 bitmap=0 CAT_LOW
14. catidx=3 bitmap=0 OTHER
15. catidx=4 bitmap=0 _ORACLE_BG_CATEGORY_
16. SIO:#served=16 #queued=0 Util=0% aqtime=0ms adtime=0ms
17. dbidx=0 bitmap=0 EDW
18. dbidx=1 bitmap=0 VISX
19. dbidx=2 bitmap=0 DWPRD
20. dbidx=3 bitmap=0 VISY
21. SIO:#served=16 #queued=0 Util=0% aqtime=0ms adtime=0ms
22. cgidx=0 bitmap=0 cgname=CG_FINANCE
23. cgidx=1 bitmap=0 cgname=CG_PROJECTS
24. cgidx=2 bitmap=0 cgname=CG_ADHOC
25. cgidx=3 bitmap=0 cgname=OTHER_GROUPS
26. cgidx=4 bitmap=0 cgname=_ORACLE_BACKGROUND_GROUP_
27. SIO:#served=16 #queued=0 Util=0% aqtime=0ms adtime=0ms
28. #concios=43652, #fragios=0 #starvedios=0 #maxcapwaits=0
29. cgidx=5 bitmap=0 cgname=_ORACLE_MEDPRIBG_GROUP_
30. cgidx=6 bitmap=0 cgname=_ORACLE_LOWPRIBG_GROUP_
31. cgidx=7 bitmap=0 cgname=_ORACLE_LOWPRIFG_GROUP_
32. dbidx=4 bitmap=0 _OTHER_DATABASE_
33. catidx=5 bitmap=0 _ORACLE_MEDPRIBG_CATEGORY_
34. catidx=6 bitmap=0 _ORACLE_LOWPRIBG_CATEGORY_
35. catidx=7 bitmap=0 _ASM_
36. SIO:#served=8 #queued=0 Util=0% aqtime=0ms adtime=0ms
... Output omitted for brevity

This section is the cellsrv statedump 's representation of the I/O queues discussed in Recipe 17-5 and
logically presented in Figure 17-1 in this chapter. Here is a brief description of some of the important lines in the
previous output:

• Line 1 marks the beginning of the IORM statistics for a specific cell disk.

• Line 2 lists the physical device for the cell disk.

• Line 7 displays

IORM boost=119 ; this represents the ratio of I/Os skipped to I/Os scheduled
and is an indication of how “active” IORM is rescheduling I/O operations.

• Lines 11 through 15 mark your Category IORM section.

• Lines 17-20 indicate your Interdatabase IORM index mappings.

• Line 21 shows that for database

VISX , 16 I/Os were being serviced at the time of the cellsrv

statedump with no queuing.
Lines 22 through 31 display the consumer groups for the •

VISX database and, in line 27, we see
the I/O requests for the _ORACLE_BACKGROUND_GROUP_ consumer group equal the total active
I/O requests for the database.

• The output in this entire section is telling us this: for disk

/dev/sda3 , at the time the cellsrv
statedump was taken, only a single database ( VISX ) had active I/O requests being serviced and
these fell into a background consumer group I/O queue.