Administrator Guide

VMware vSphere and Live Volume
67 Dell EMC SC Series: Synchronous Replication and Live Volume | CML1064
Configuring vSphere HA for PDL and APD conditions
The Disk.AutoremoveOnPDL advanced setting is not configurable in VMCP and should remain at its default
value of 1 for each vSphere 6 host in the cluster. For more information on the Disk.AutoremoveOnPDL
feature, refer to VMware KB article 2059622, PDL AutoRemove feature in vSphere 5.5 and vSphere 6.0.
In a non-uniform configuration, if an outage impacts primary Live Volume availability and Live Volume
automatic failover cannot occur, vSphere HA will not be able to immediately restart impacted virtual
machines.
If the VMware virtual infrastructure is version 4.0 or earlier, vSphere Metro Storage Cluster is not supported
and other steps should be taken to prevent virtual machines from unexpectedly running from the secondary
Live Volume. An individual VM or group of VMs may be associated with a DRS rule that keeps them together
but this does not guarantee they will stay over a period of time on the same host or group of hosts where the
primary Live Volume is located. As a last resort, DRS can be configured for manual mode or disabled when
using Live Volume in a multi-site configuration that will prevent the automatic migration of VMs to Secondary
Live Volume hosts in the same cluster.
VMware vSphere monitors SCSI sense codes sent by an array to determine if a device is in a PDL state.
These SCSI sense codes are outlined in VMware KB article 2004684, Permanent Device Loss (PDL) and All-
Paths-Down (APD) in vSphere 5.x and 6.x. SC Series storage supports two SCSI sense codes (see Table 1)
which will be sent to vSphere hosts when a PDL condition is met.
SCSI sense codes
SCSI sense code
Description
H:0x0 D:0x2 P:0x0 Valid sense data: 0x4 0x3e 0x1
LOGICAL UNIT FAILURE
H:0x0 D:0x2 P:0x0 Valid sense data: 0x5 0x25 0x0
LOGICAL UNIT NOT SUPPORTED
8.15 vSphere Metro Storage Cluster and Live Volume Requirements
A vSphere Metro Storage Cluster (vMSC) design with Live Volume requires the following:
• Dell SCOS 6.7 or newer with both SC Series arrays having the same firmware version
• Dell Storage Manager 2015 R2 or newer with tiebreaker service located at a site physically
independent of SC Series arrays