Modification of congestion-related vSAN advanced parameters

Products

• VMware vSAN
• VMware vSAN 6.x
• VMware vSAN 7.x
• VMware vSAN 8.x

Issue/Introduction

• Modification of certain vSAN advanced configuration options can result in unexpected side effects.
  
  Warning: VMware strongly advises against modification of any congestion-related advanced configuration parameters.

Environment

• VMware vSAN (All Versions)

Resolution

VMware vSAN has a variety of advanced configuration parameters that modify how vSAN handles I/O requests, data management, data protection and various other aspects of the vSAN infrastructure. Although some advanced configuration parameters are useful, others can have profound implications on data integrity, reliability, and availability. Long-term changes or misconfiguration of these values can result in data unavailability or data loss.

VMware strongly advises against modification of any congestion-related advanced configuration parameters. This includes, but is not limited to, the following options:

• /LSOM/lsomMemCongestionLowLimit
  • Default value: 75
     
• /LSOM/lsomMemCongestionHighLimit
  • Default value: 95
     
• /LSOM/lsomSsdCongestionLowLimit
  • Default value: 75
     
• /LSOM/lsomSsdCongestionHighLimit
  • Default value: 95
     
• /LSOM/lsomLogCongestionLowLimitGB
  • Default value: 16
     
• /LSOM/lsomLogCongestionHighLimitGB
  • Default value: 24

 

 It is not supported to adjust these values for production clusters outside of specific guidance from Broadcom Support. If you are going to consider making changes please consult with support via a support case before making these changes.