Veritas Dynamic Multipathing (VxDMP) cannot send I/O to paths with NDELAY on AIX systems.
Article ID: 100011015
Updated On:
Description
Error Message
NOTE VxVM vxdmp V-5-3-0 Reached DMP Threshold IO TimeOut (300) for disk
Cause
VxDMP cannot use path with NDELAY flag set.
| HDS | EMS |
| The NDELAY flag is due to the “reserve_policy” device attribute being set to “single_path” instead of “no_reserve.” | The NDELAY flag is due to the “reserve_lock” device attribute being set to “yes" instead of "no." |
Resolution
Private Hot Fix 6.0.3 HF103 has been released to address this issue.
The hotfix now addresses the NDELAY being set on a path. After installing the hotfix and rebooting, the reserve_policy will show as “no_reserve” for HDS, and "reserve_lock" will show as "no" for EMC. The hotfix addresses any kind of error state to guaranty retry on another path. For example, if there is a queue full at HBA level and it returns an error, then VxDMP will retry on another path.
This issue has been identified and a private fix is available. To obtain the private fix, contact Veritas Enterprise Technical Support and reference this article during the call. A support representative will be available to assist in troubleshooting this issue. If it is determined that the private fix addresses the problem, the support representative will further assist in obtaining the private fix. For a complete list of Veritas Technical Services contact numbers and information about support costs, go to https://supportinfoscale.cloud.com/support-home/home.
Issue/Introduction
Veritas Dynamic Multipathing (VxDMP) cannot send I/O to paths with NDELAY on AIX systems. This can lead to a situation where a disk is detached after reaching DMP Threshold IO TimeOut as VxDMP only has one path available for I/O.
Additional Information
ETrack: 3346382
