Skip to Main Content
IBM Power Ideas Portal

This portal is to open public enhancement requests against IBM Power Systems products, including IBM i. To view all of your ideas submitted to IBM, create and manage groups of Ideas, or create an idea explicitly set to be either visible by all (public) or visible only to you and IBM (private), use the IBM Unified Ideas Portal (

Shape the future of IBM!

We invite you to shape the future of IBM, including product roadmaps, by submitting ideas that matter to you the most. Here's how it works:

Search existing ideas

Start by searching and reviewing ideas and requests to enhance a product or service. Take a look at ideas others have posted, and add a comment, vote, or subscribe to updates on them if they matter to you. If you can't find what you are looking for,

Post your ideas
  1. Post an idea.

  2. Get feedback from the IBM team and other customers to refine your idea.

  3. Follow the idea through the IBM Ideas process.

Specific links you will want to bookmark for future use

Welcome to the IBM Ideas Portal ( - Use this site to find out additional information and details about the IBM Ideas process and statuses.

IBM Unified Ideas Portal ( - Use this site to view all of your ideas, create new ideas for any IBM product, or search for ideas across all of IBM. - Use this email to suggest enhancements to the Ideas process or request help from IBM for submitting your Ideas.

Status Not under consideration
Workspace IBM i
Created by Guest
Created on Jan 11, 2023

Would like greater visibility for vNode Pool stress and IFS seize/contention

Worked with IBM to troubleshoot an IFS performance issue that grew slowly but then caused production issues for a couple of weeks.  The problem was ultimately found to be use of an old API SYSTOOLS.httpGetClob() that spawns a Java JVM for every call.  The offending code was making calls from multiple programs and menus and caused the JVM count on the IBM i to go from 58 to 1000+.  This rapid increase in JVM count at peak time of day eventually caused IFS performance issues in the form of an increase in general lock or "seize contention" and exhaustion of "Vnodes".  As we struggled to determine root cause it became clear the current tools such as iDoctor Job Watcher and Help Systems Performance Navigator could not track "exhaustion of VvNodes".  

A Vnode is an object in kernel memory that speaks the UNIX file interface (open, read, write, close, readdir, etc.) apparently. Vnodes can represent files, directories, FIFOs, domain sockets, block devices, character devices.  Prior to this issue I had no idea what a VNode was and how to track when it is "stressed".  We had difficulty pinpointing this issue as iDoctor Job Watcher, IFS dumps and MGTOOLS SYSSNAP were showing different processes at the top of the stack each time the IFS performance slowdown occurred.  Through general observance I figured out the issue was the many JVM's that would ramp up during testing of a new process and the processes at the top of the stack were merely victims during the slowdown as they were all writing to the IFS.

Would like IBM to provide enhancements to current iDoctor tools and perhaps the recent SQL services associated with WRKJVMJOB command could be enhanced to allow tracking of Vnode pool exhaustion so we can be more proactive in resolving issues. 

Idea priority High
  • Guest
    Jan 13, 2023
    We are declining this request.

    Usage of integrated file system objects can be determined with the use of SQL services such as IFS_JOB_INFO, IFS_OBJECT_LOCK_INFO, and IFS_OBJECT_REFERENCES_INFO, or through APIs Retrieve Referenced Objects (QP0LRRO) and Retrieve Object References (QP0LROR). Access to integrated file system objects is synchronized through the use of mutexes. Mutex contention is tracked/analyzed with Job Watcher. We do not plan to include any form of internal structures in the Job Watcher data.

    IBM Power Systems Development