Error Message

VxVM vxdmp V-5-3-0 dmp_indirect_ioctl: Open failed on path with ret 47

The VxVM commands "vxdisk scandisks/vxdctl enable" commands do an open call on devices. If the open call fails then Dynamic Multipathing (DMP) error messages are generated.

For Write Disabled (WD) / Not Ready (NR) state devices, the open call is expected to fail. Hence, these DMP error messages are logged to the syslog file.

 

 

Code changes are done to suppress the DMP related error messages with the default DMP log level (1). The DMP messages will be seen when the DMP log level is 2 or higher.

Please contact Veritas Support if you require the VxVM Private hot-fix 6.0.500.3 for AIX.

 

 

Applies To

Cross-platform.

The Veritas Volume Manager (VxVM) commands "vxdisk scandisks / vxdctl enable" trigger DMP related messages for devices with a Write Disabled (WD) / Not Ready (NR) state.

The DMP related messages can flood the syslog file as a consequence. Some arrays provide a way to dynamically change the properties of LUNs.

For example, the EMC Symmetrix array allows write-protected/write-disabled (WD|read-only), not-ready (NR) and read-write (RW) enabled LUN attribute content to be exposed to DMP.
This is possible by using the EMC specific ASL to extract disk based content from defined areas on the disk via a SCSI inquiry operation. 

As long as the disk is capable of presenting LUN specific content using SCSI inquiry commands, the array based ASL can be enhanced to expose such value add content.


To enable Veritas Volume Manager (VxVM) in connection with DMP to make such LUN characteristics available and consistent, specific steps are required.
  Veritas recommend taking the device offline before detecting changed LUN properties. Once the LUN attributes have changed to the required state, the device can then be brought back online again.
 
Steps

1.] # vxdisk offline <Veritas-disk-access-name> 2.] Perform array activity 3.] # vxdisk online <Veritas-disk-access-name>


Intelligent LUNs


In certain cases, such device types as EMC BCV (Hardware Clone) and SRDF (Hardware Replicated) can remain online as DMP is fully aware of the LUN characteristics via the intelligence provided via the EMC ASL.
The DMP extended attribute content can be displayed in many ways for such intelligent storage arrays using the VxVM "vxdisk -e list" CLI command, and in later versions using the "vxdisk -px LIST_CLONE list" command.
With such intelligent device types, the DMP extended attribute may still require a manual refresh using the VxVM "vxdisk scandisks" CLI command. 
Once the device status reflects the required state, DMP should be manually updated with the new LUN details to ensure the appropriate VxVM command outputs do reflect the current LUN characteristics.
Steps

1.] The H/W Clone/Replicate device state is being intentionally modified/changed. 2.] The H/W related activity i s complete . 3.] Refresh VxVM and DMP extended attribute content.

# vxdisk scandisks

In a clustered environment, the manual refresh of the extended attributes needs to be performed across all nodes in the cluster.


Recommendation: VxVM product releases 6.0.5 and 6.1.1 (MR1) or higher should be deployed where possible to benefit from additional functionality enhancements.

Example:

For AIX deployments, a minimum of 6.05 must be installed for VxVM to correctly detect H/W device states.  
Veritas also recommends applying the latest VRTSaslapm updates posted on https://sort.Veritas.com/land.

ETrack: 3560581 (Tracking ID: 3560576)