The onstat -g iov Option

The onstat -g iov option shows asynchronous I/O statistics for each virtual processor.

Example Output

Figure 65. onstat -g iov Output

IBM Informix Dynamic Server Version 10.00.UC1 -- On-Line -- Up 01:56:26 -- 101376 Kbytes
AIO I/O vps:
class/vp s  io/s totalops dskread dskwrite dskcopy  wakeups io/wup polltries pollfound kaio_pend
fifo  0  i  0.0  0        0       0        0        0        0.0    0         0         0 
fifo  1  i  0.0  0        0       0        0        0        0.0    0         0         0 
msc   0  i  0.0  0        0       0        0        0        0.0    0         0         0 
aio   0  s  0.3  628      0       628      0        628      1.0    0         0         0

Output Description

class

The class of the virtual processor.

vp

The ID number of the virtual processor within its class.

s

Current status of the AIO virtual processor

f: Fork
i: Idle
s: Search
b: Busy
o: Open
c: Close

io/s

The average I/O speed (measured in operations per second) for the virtual processor since the time the database server started or since onstat -z was last run, whichever happened last.

totalops

Total number of I/O operations performed by this virtual processor since the time the database server started or since onstat -z was last run, whichever happened last.

dskread

Total number of read operations performed by this virtual processor since the time the database server started or since onstat -z was last run, whichever happened last.

dskwrite

Total number of write operations performed by this virtual processor since the time the database server started or since onstat -z was last run, whichever happened last.

dskcopy

Total number of copy operations performed by this virtual processor since the time the database server started or since onstat -z was last run, whichever happened last.

wakeups

For AIO VPs, the number of times the virtual processor has gone idle since the time the database server started or since onstat -z was last run, whichever happened last.

io/wup

For AIO VPs, the average number of I/O operations performed per wake-up by this virtual processor since the time the database server started or since onstat -z was last run, whichever happened last.

polltries

For AIO VPs, the total number of times the kaio thread running on this virtual processor checked the operating system to see if I/O it had requested was done. Count is from the time the database server started or since onstat -z was last run, whichever happened last.

pollfound

For AIO VPs, the total number of times the kaio thread running on this virtual processor checked the operating system to see if I/O it had requested was done and found that the I/O was complete. Count is from the time the database server started or since onstat -z was last run, whichever happened last.

kaio_pend

For AIO VPs, the number of I/O requests made by the kaio thread that have not yet completed.