728x90


Problem(Abstract)

You try to start the Informix server but it fails to start with messages like these in the online.log: 21:45:30 IBM Informix Dynamic Server Started. 21:45:30 size of resident + virtual segments 10443875920 + 4831838208 > 9663676416 total allowed by configuration parameter SHMTOTAL

Symptom

  • output of oninit -v:

    Checking group membership to determine server run mode...succeeded
    Reading configuration file '/opt/informix/etc/onconfig.test'...succeeded
    Creating /INFORMIXTMP/.infxdirs...succeeded
    Checking config parameters...succeeded
    Allocating and attaching to shared memory...FAILED
  • messages in online.log:

    21:45:30 IBM Informix Dynamic Server Started.
    21:45:30 size of resident + virtual segments 10443875920 + 4831838208 > 9663676416
    total allowed by configuration parameter SHMTOTAL

Cause

The size of the resident and virtual portions of shared memory exceed the shared memory limit set by the onCONFIG parameter SHMTOTAL.


Resident portion of shared memory 
The resident portion of the database server shared memory stores the following data structures that do not change in size while the database server is running:

  • Shared-memory header
  • Buffer pool
  • Logical-log buffer
  • Physical-log buffer
  • Lock table

Virtual portion of shared memory 
The virtual portion of shared memory size is determined by the value of the onCONFIG parameter SHMVIRTSIZE and stores the following data:
  • Internal tables
  • Big buffers
  • Session data
  • Thread data (stacks and heaps)
  • Data-distribution cache
  • Dictionary cache
  • SPL routine cache
  • SQL statement cache
  • Sorting pool
  • Global pool

Diagnosing the problem

Resolving the problem

  • Increase the value of the onCONFIG parameter SHMTOTAL if possible.
  • Decrease the value of one or more of these onCONFIG parameters:

    - BUFFERPOOL ( the buffers value )
    - LOCKS
    - SHMVIRTSIZE


728x90

+ Recent posts