onstat -F

Use the -F option to display a count for each type of write that flushes pages to disk.

Example Output

Figure 36. onstat -F Output

IBM Informix Dynamic Server Version 10.00.UC1 -- On-Line -- Up 04:00:17 -- 15360 Kbytes


Fg Writes     LRU Writes    Chunk Writes 
0             0             0            

address  flusher  state    data    
a4d8628  0        I        0        = 0X0       
      states: Exit Idle Chunk Lru

Output Description

You can interpret output from this option as follows:

Fg Writes

Is the number of times that a foreground write occurred

LRU Writes

Is the number of times that an LRU write occurred

Chunk Writes

Is the number of times that a chunk write occurred

address

Is the address of the user structure assigned to this page-cleaner thread

flusher

Is the page-cleaner number

state

Uses the following codes to indicate the current page-cleaner activity:

C: Chunk write
E: Exit
I: Cleaner is idle
L: LRU queue

The exit code indicates either that the database server is performing a shutdown or that a page cleaner did not return from its write in a specific amount of time. When an operation fails to complete within the allotted time, this situation is known as a time-out condition. The database server does not know what happened to the cleaner, so it is marked as exit. In either case, the cleaner thread eventually exits.

data

Provides additional information in concert with the state field

If state is C, data is the chunk number to which the page cleaner is writing buffers. If state is L, data is the LRU queue from which the page cleaner is writing. The data value is displayed as a decimal, followed by an equal sign, and repeated as a hexadecimal.