VMware vSAN Consideration

In this blog post I will list some vSAN Considerations from the Design perspective

vSAN Design Resources

• VMware Virtual SAN Design and Sizing Guide 
• VMware vSAN 6.7 U1 Deep Dive
• VMware vSAN HCL
• vSAN Sizer

Availability Consideration

• HA works differently with vSAN
• When HA is ON , HA traffic (Heartbeat) goes on vSAN Network
• Make sure that HA is disabled before enabling vSAN
• HA cannot use datastore Heartbeats when vSAN is enabled, only vSAN datastore is enabled

Disk Consideration

• Review vSAN HCL
• Flash capacity not added to the total capacity
• Flash is used 30 % Write , 70% Read
• Flash should be sized based on 10 % of the storage you expected to consume
• ESXi can be booted from USB or SD card
• Recommeded to use a multiple small Disk groups than larger Disk groups
• You cannot mix all flash + hybrid hosts at the same cluster

Network Consideration

• vSAN Compatible with vSS and vDS
• Use 1 GBE Network but it’s recommended to use 10 GBE
• It’s recommended to use vDS and Network I/O control (NIOC)
• Recommended to separate traffic into VLANS

Hardware consideration

• vSAN is designed to not use more than 10 CPU per host
• vSAN required RAID controller or HBA that support Passthrough or Pseudo passthrough mode

Configuration Maximums

• Always refer to VMware vSAN Configuration Maximums
• Max of 5 disk Groups
• Max of 8 disks (1 flash + 7 HDD) per disk Group
• Max hosts in a vSAN Cluster = 64
• The configuration Maximums can be checked through vsanConfigMaximumcheck.pl script
• vSAN Memory Consumption and also this is a nice vSAN Memory calculator.