VMWare Information Gathering Questions


  1. What is your VSPHERE Version:
  2. Number of SAS Virtual Machines:
  3. Are SAS VMs part of a larger VM Farm?
  4. Is the VM Farm On-Prem or Cloud Based?
  5. VM Subscription
    1. Are the VMs statically reserved, or vMotioned?
      1.  If vMmotion runs during a SAS process, the disruption is disabling. 
  6. Are the VMs sharing/borrowing/stealing resources (CPU/Memory)?
    1. Is CPU Hot Add enabled? If so, please disable.
    2. How thinly provisioned are the VMs?
  7. VM Backup Schedule
    1. Are hypervisor level backups used?
      1. It is recommended to Not Allow Hypervisor level backups during SAS Job executions.
    2. Are physical host level backups used?
      1. It is recommended to Not Allow HOST level backups during SAS Job executions.
      2. These should be placed on a non-interfering schedule.
    3. What is the backup schedule?
  8. VM Placement
    1. Are the SAS VMs in the same ESXi cluster? This is optimal.
    2. Are the SAS Virtual Machine hosts contained within the same local subnet? It is best to do this.
    3. Are the SAS Virtual Machine hosts and memory for each VM, contained within the same single socket? If not, NUMA problems can persist despite VMWare attempts to control it.
    4. Are different SAS VMs collocated on the same physical host?
    5. Are the SAS VMs Multi-Tenant, Single Tenant Dedicated Host, or Singe Tenant Dedicated Instance?
    6. Are the physical hosts 2 Socket, or 4 Socket Host?
  9. Network
    1. Is the VM cluster using VMXNET3?
    2. What is the Network bandwidth between VMs (NIC through Switch)?
    3. Are there adequate NIC/FC card resources to support each VM, in a given physical host to permit at least 100 MB/sec/core IO Bandwidth to external storage? This is required for SAS I/O for SAS GRID Compute Nodes and SAS Viya Worker Nodes.
    4. Are Paravirtual SCSI Controller/Adapters used?
    5. If PVSCSI Adapters are used, has the queue depth and ring page count within the virtual machine been increased? https://kb.vmware.com/s/article/2053145
      vmw_pvscsi.cmd_per_lun=254
      vmw_pvscsi.ring_pages=32
      The second line ensures persistence after a reboot https://kb.vmware.com/s/article/2150431
  10. Storage
    1. Is the VM Consumed Storage in the same data center as the VMs? Is it collocated on the same ESXi cluster, or on the same subnet?
    2. Is VMDKs placed on FC, PVSCSI, or Network Attached storage?
    3. Are VM disks thick provisioned/eager zeroed?
    4. What is the host adapter bandwidth to external storage?
    5. Do all of the SAS VMs have consonant MTU settings on NIC cards?
    6. Can you provide any Network Attached, SAN, HCI, or local Storage Vendors and Model Numbers?
    7. Is any external storage shared with non-SAS applications or is it dedicated to SAS?

Vendor STORAGE Specific Considerations

There are many Vendor storage specific considerations for VM Cluster tuning for storage optimization. These are a few topics. Please work with your Storage Vendor for more specific recommendations based on your SAS®9/SAS® Viya® usage.