ESXi host non responsive do to RDM Reservation confits.

Products

• VMware vSphere ESXi

Issue/Introduction

ESXi host has gone non responsive in vCenter and you find that there are "0x18" sense code reservation conflicts for RDMs. 

 

 

Environment

ESXI 7.x

ESXI 8.x

 

Cause

The issue occurs when virtual machines participating in a clustering solution such as WSFC, Red Hat High Availability Cluster use shared RDMs and SCSI reservations across hosts, and a virtual machine on the other host is the active cluster node holding a SCSI Reservation.  When this happens you can exhaust Hostd, causing the ESXi host to go in to a non responsive state from vCenter . 

 

 

 

 

Resolution

Mark the LUNs as perennially reserved:

1. Determine which RDM LUNs are part of WSFC, Red Hat High Availability Cluster etc . From the vSphere Client, select a virtual machine that has a mapping to the cluster RDM devices.
2. Edit your virtual machine settings and navigate to your Mapped RAW LUNs. In this example, Hard disk 2:
   
   
    
3. In the Physical disk, there is the specification of the device in use as RDM (that is, the VML ID).
   
   Take note of the VML ID, which is a globally unique identifier for your shared device.
    
4. Identify the naa.id for this VML using this command:  esxcli storage core device list
   
   For example:
   
   esxcli storage core device list
   
   naa.6589cfc000000a17ac02aae02067e747
      Display Name: FreeNAS iSCSI Disk (naa.6589cfc000000a17ac02aae02067e747)
      Has Settable Display Name: true
      Size: 40960
      Device Type: Direct-Access
      Multipath Plugin: NMP
      Devfs Path: /vmfs/devices/disks/naa.6589cfc000000a17ac02aae02067e747
      Vendor: FreeNAS
      Model: iSCSI Disk
      Revision: 0123
      SCSI Level: 6
       Is Pseudo: false
      Status: degraded
      Is RDM Capable: true
      Is Local: false
      Is Removable: false
      Is SSD: false
      Is VVOL PE: false
      Is Offline: false
      Is Perennially Reserved: false
      Queue Full Sample Size: 0
      Queue Full Threshold: 0
      Thin Provisioning Status: unknown
      Attached Filters:
      VAAI Status: supported
      Other UIDs: vml.0100010000303035303536################################
      Is Shared Clusterwide: true
      Is SAS: false
      Is USB: false
      Is Boot Device: false
      Device Max Queue Depth: 128
      No of outstanding IOs with competing worlds: 32
      Drive Type: unknown
      RAID Level: unknown
      Number of Physical Drives: unknown
      Protection Enabled: false
      PI Activated: false
      PI Type: 0
      PI Protection Mask: NO PROTECTION
      Supported Guard Types: NO GUARD SUPPORT
      DIX Enabled: false
      DIX Guard Type: NO GUARD SUPPORT
      Emulated DIX/DIF Enabled: false
   
   
5. Use the esxcli command to mark the device as perennially reserved:
   
   esxcli storage core device setconfig -d naa.id --perennially-reserved=true
   
   For example:
   
   esxcli storage core device setconfig -d naa.6589cfc000000a17ac02aae02067e747 --perennially-reserved=true
   
   Note: For vSphere 7.x, see the Change Perennial Reservation Settings section of the vSphere Storage Guide.
    
6. To verify that the device is perennially reserved, run this command:
   
   esxcli storage core device list -d naa.id
   
   In the output of the esxcli command, search for the entry Is Perennially Reserved: true. This shows that the device is marked as perennially reserved.
   
   For example:
   
   esxcli storage core device list -d naa.6589cfc000000a17ac02aae02067e747
   
   naa.6589cfc000000a17ac02aae02067e747
      Display Name: FreeNAS iSCSI Disk (naa.6589cfc000000a17ac02aae02067e747)
      Has Settable Display Name: true
      Size: 40960
      Device Type: Direct-Access
      Multipath Plugin: NMP
      Devfs Path: /vmfs/devices/disks/naa.6589cfc000000a17ac02aae02067e747
      Vendor: FreeNAS
      Model: iSCSI Disk
      Revision: 0123
      SCSI Level: 6
      Is Pseudo: false
      Status: degraded
      Is RDM Capable: true
      Is Local: false
      Is Removable: false
      Is SSD: false
      Is VVOL PE: false
      Is Offline: false
      Is Perennially Reserved: true
      Queue Full Sample Size: 0
      Queue Full Threshold: 0
      Thin Provisioning Status: unknown
      Attached Filters:
      VAAI Status: supported
      Other UIDs: vml.0100010000303035303536################################
      Is Shared Clusterwide: true
      Is SAS: false
      Is USB: false
      Is Boot Device: false
      Device Max Queue Depth: 128
      No of outstanding IOs with competing worlds: 32
      Drive Type: unknown
      RAID Level: unknown
      Number of Physical Drives: unknown
      Protection Enabled: false
      PI Activated: false
      PI Type: 0
      PI Protection Mask: NO PROTECTION
      Supported Guard Types: NO GUARD SUPPORT
      DIX Enabled: false
      DIX Guard Type: NO GUARD SUPPORT
      Emulated DIX/DIF Enabled: false
    
7. Repeat the procedure for each Mapped RAW LUN that is participating in the clustering solution such as WSFC, Red Hat High Availability Cluster, etc.
   
   Note: The configuration is permanently stored with the ESXi host and persists across restarts. To remove the perennially reserved flag, run this command:
   
   esxcli storage core device setconfig -d naa.id --perennially-reserved=false
8. If the host does not come back up after setting perennially-reserved=false  Reboot host to get back into Vcenter. 

Additional Information

RDMs that are not perennially reserved can also cause long boot times. 

ESXi host takes a long time to start during rescan of RDM LUNs