Oninit
Talk to an expert →

Informix Error -1257: Operating system cannot fork process for back end.

Cause and resolution

Operating system cannot fork process for back end.

Back end refers to the database server. If this is an internal error, look for operating-system messages that might give more detail. In DOS systems, you probably are out of memory; exit to the operating-system command line, and resubmit your program. After you verify that no system limit or local problem exists, note all circumstances and contact IBM Informix Technical Support.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-1257 fires when the operating system fails to create (fork) a new process for the database server back end — per the official guidance, on DOS systems memory exhaustion is a common culprit.

  1. Memory exhaustion, per the official guidance's specific DOS-platform note — the named common cause there.
  2. An OS-level process limit reached, more generally, on other platforms.
Solutions / Resolution
  1. Check for operating-system messages for additional details, per the official guidance.
  2. On DOS systems, exit to the command line and retry, per the official guidance's specific remedy for memory exhaustion there.
  3. If no local system resource issues exist, contact IBM Informix Technical Support with full context about the circumstances, per the official guidance.
Examples
N/A

No specific triggering statement is documented — this is an OS-level process-creation failure.

Diagnostic Checks
  1. Check OS-level process/memory limits for the account running the database server.
  2. Check the operating-system error log for the specific fork failure reason.
Related Errors / Related Topics
  • -1250 — "Unable to create pipes." A related connection-initialization error, about a different OS facility (pipes) failing.
  • -1258 — "Cannot attach to shared memory used to communicate with back end." A related back-end connection error, about shared memory rather than process creation.

The OS couldn't fork a process for the database server back end — check memory/process limits and OS error messages.