Hi ,

I would like to share this issue with the community for knowledge sharing, related to a VIOS major upgrade (3.1.4.50 → 4.1.0.10), along with the findings and resolution steps.

Problem

The viosupgrade command fails when upgrading, reporting that the target disk is in use and halting the upgrade process before completion.

Symptom

The following output is observed during the upgrade attempt:

WARNING!!! VIOS Upgrade operation is in progress. Kindly refrain from making any configuration changes... Please wait for completion.. Upgrading from ioslevel '3.1.4.50' to '4.1.0.10'. The provided disk 'hdisk#' is in use.

Cause

The upgrade fails due to incorrect use of the mkvg -a option within alt_disk_mksysb, or the crfs logname=OUTLINE option. Both options were introduced in AIX 7.3 and are not available in earlier versions, causing the upgrade process to fail and leaving the disk flagged as in use.

Environment

• Platform: PowerVM / Virtual I/O Server (VIOS)
• Scenario: Major version upgrade (e.g., VIOS 3.1.x to 4.1.x)

Diagnosing the Problem

Step 1 - Check for APAR IJ50614
First, verify whether the system is affected by the known defect:

IJ50614: VIOS upgrade fails between major VIOS versions - applies to AIX 7300-03
https://www.ibm.com/support/pages/apar/IJ50614

Step 2 - Confirm disk availability
Run one of the following commands to verify the disk is not genuinely allocated:

lspv -free

or

lspv -unused

Resolving the Problem

Step 1 - Release the disk
Attempt to release the disk from the alternate rootvg and clear its PVID reservation:

# alt_rootvg_op -X altinst_rootvg

# chpv -C hdisk1

Then reattempt the upgrade. If the issue persists, proceed to Step 2.

Step 2 - Force-clear the disk headers (destructive)

⚠️ CAUTION: The commands below will permanently erase all data on the target disk. Double-check that hdisk# refers to the correct upgrade disk and that no required data remains on it. This action cannot be undone.

If the disk headers are corrupted and the disk cannot be released cleanly, zero out the first blocks and re-clear the PVID:

# dd if=/dev/zero of=/dev/hdisk1 bs=4k count=1000

# chpv -C hdisk1

Step 3 - Retry the upgrade
Reattempt the viosupgrade command. Upon successful completion, confirm the new VIOS level:

ioslevel

Expected output example:

4.1.0.10

The output should match the target version specified in the upgrade command.

Additional Information – IBM Support

If further assistance is required, follow these steps to open a case with IBM Support:

1. Document all symptoms, errors, and messages (screenshots if possible)
2. Collect relevant logs and diagnostic data
3. Open a case with IBM Support:
• https://www.ibm.com/mysupport
• https://www.ibm.com/planetwide/
4. Provide a clear and concise problem description
5. If the system is accessible, collect a snap and upload all relevant data

For more details:
Working with IBM AIX Support: Describing the problem

IBM Technote Reference

For full details and the official IBM troubleshooting guide, please refer to:

• PowerVM/VIOS – "The provided disk hdisk# is in use" during upgrade

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Anas AlSaleh
IBM Power Systems Software Specialist
Saudi Business Machines ( SBM )
Riyadh
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