Informix Error -195: ISAM error: No miscellaneous vp.

Reasons / Common Causes

-195 means the engine's virtual processor (VP) configuration has no VPs allocated to the "miscellaneous" (misc) class — a class that handles certain background and administrative tasks — and something needed one.

1. The VPCLASS configuration in ONCONFIG doesn't include any virtual processors for the misc class. An operation requiring that VP class to run finds none available.
2. A misconfigured or incomplete VPCLASS setup, edited or reduced without realizing the misc class needed at least one VP for certain operations to function.
3. A version upgrade changing which VP classes are required or expected, with ONCONFIG not updated to reflect the new requirement.
4. Manual reduction of VP classes during resource-constrained tuning, inadvertently removing the misc class entirely rather than just reducing its count.

Solutions / Resolution

1. Check the current VPCLASS configuration to confirm whether misc-class VPs are configured at all:

   grep -i "^VPCLASS" $ONCONFIG
   

2. Add at least one VP for the miscellaneous class:

   VPCLASS misc,num=1
   

   and reinitialize or restart the engine as needed for the change to take effect.
3. Review recent VP configuration changes from tuning or upgrade activity, to identify when this class might have been inadvertently removed rather than deliberately reduced.
4. Consult the Administrator's Guide for the exact VPCLASS syntax and recommended minimum configuration for the specific version in use.

Examples

The missing configuration line

# ONCONFIG — misc class entirely absent
VPCLASS cpu,num=4
VPCLASS aio,num=2
# no VPCLASS misc line at all

Adding it:

VPCLASS cpu,num=4
VPCLASS aio,num=2
VPCLASS misc,num=1

A tuning pass that went too far

An administrator reducing VP counts during resource-constrained tuning removes the misc class entirely, believing it wasn't being used — only to discover -195 the next time an operation that depends on it runs. Restoring at least one misc VP resolves it.

Diagnostic Checks

1. Check current VP class configuration and counts:

   onstat -g glo
   

2. Review the VPCLASS lines in ONCONFIG directly for the misc class.
3. Review recent configuration change history if this appeared unexpectedly after a tuning pass or upgrade.

Related Errors / Related Topics

• -100 — "ISAM error: duplicate value for a record with unique key." The other foundational ISAM-level error in this family.
• -123 — "ISAM error: no shared memory." A different engine-infrastructure prerequisite — both point at a foundational configuration element (shared memory, VP classes) missing rather than an application-level cause.

Check the VPCLASS configuration directly — this is a straightforward configuration gap, not something to diagnose from the application side.