VCAP-DCV Deploy Objective 2.3

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Finally we got to the troubleshooting part!. In this post i will ONLY suggest some ideas to look for information. at this point we need to have a good understanding on how storage works with vSphere 6.

Here are the objective from the blueprint that we going to cover in this post:

  • Analyze and resolve storage multi-pathing and failover issues
  • Troubleshoot storage device connectivity
  • Troubleshoot iSCSI connectivity issues
  • Analyze and resolve NFS issues
  • Troubleshoot RDM issues
  • Analyze and resolve Virtual SAN configuration issues

Lab Setup:

Using VMware workstation:

  • Microsoft Servers 2012R2 for Services (DNS , DHCP, etc…)
  • installed esx0/esx1/esx2
  • Installed VCSA
  • iSCSI Storage

 Documents used:

  • vSphere6 Storage Guide
  • VMware Virtual SAN administration Guide
  • VSAN Troubleshooting Reference Manual
  • vSphere Troubleshooting
  • VMware KB 1027963


Analyze and resolve storage multi-pathing and failover issues and Troubleshoot storage device connectivity

  • Check for correct configuration
    • Hardware and Software
    • Connectivity
  • Examine the relevant logs
    • /var/log/vmkernel
    • looking for NMP messages in the vmkernel logs

The below picture show what happens when you disconnect the storage from the network (you should try to understand the sequance of events)


  • In ISCSI case check for Port binding configuration
    • check the network configuration
  • Use the CLI utils to gather information
    • Get info about the storage device you trying to troubleshoot esxcli storage core device list
    • check the multi-path configure with esxcfg-mpath command for example:  esxcfg-mpath -b -d naa.60014054ddcf82083c44f8da7394198a
    • Verify load balancing using RR policy
    • use esxtop to monitor iSCSI adapter transmit I/O


Troubleshoot iSCSI connectivity issues:

  • Check connectivity to the iSCSI storage device using ping and vmkping
  • Check the iSCSI software configuration
    • IP’s to the target
    • Correct ports
    • Network binding configuration
    • iqn’s
    • Status : Enable/Disable
  • Check for CHAP configuration on both the iSCSI initiator and the storage
  • Examine the relevant logs
    • /var/log/vmkernel

Analyze and resolve NFS issues:

  • Check networking configuration
    • IP’s
    • Ports
    • Firewall
  • Check the switch configuration
    • VLAN’s
    • MTU
    • Routing if using L3 switch
  • Check Protocol configuration
    • export configuration on the storage device (TCP/UDP)
    • Permission to mount the NFS export
    • authentication if using NFS4.1

Troubleshoot RDM issues:

Virtual Machines with RDMs Need to Ignore SCSI INQUIRY Cache  is the only reference for this objective. there are a lot of other RDM issues but its in regards to other features

so From VMware Troubleshooting guide the solution for the above issue is:

” Configure the virtual machine with RDM to ignore the SCSI INQUIRY cache by adding the following parameter to the .vmx file. scsix:y.ignoreDeviceInquiryCache = “true” where x is the SCSI controller number and y is the SCSI target number of the RDM. Enable this parameter only when your storage vendor recommends that you do so. This parameter is required for just a limited number of storage arrays and only for specific guest operating systems.”

Analyze and resolve Virtual SAN configuration issues:

VMware has a VERY good guide on vSAN troubleshooting and you can learn a lot from it the link for the document:

For this task we need to understand how to analyse and resolve vSAN configuration issues ( i think the emphasis is on configuration)

I will check the followings:

  • Check the health of an object in vSAN
  • Check for VM compliance in vSAN
  • Check HW comparability
    • Drivers
    • Firmware
    • Storage I/O controller
  • Check fog a physical hardware failure
    • HDD/SSD
    • NICS
    • Server
  • Check for connectivity issues
    • VMkerenel adapter for vSAN,
    • Switch/Network configuration
    • Multicast on physical Switch
  • Check vmkernel.log


Thanks for reading




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