Why does a virtual machine freeze during a VMware snapshot
Applies to
- E-Series
 - VMware ESXi
 - Veeam
 
Answer
This is expected behavior, operating system (OS) requires a consistent snapshot for a successful recovery to achieve this two separate operations must occur. Active RAM state must be captured and the disk IO must be quiesced
Explanation:
- In testing we have observed virtual machine (VM) suspend or ping request timed out from snaphot create, deletion and consolidation
 - Factors that influence this behavior and length of unresponsiveness
    
- If Snapshot includes VM active memory
 - Host based SSD caching
 - Storage processor cache utilization
 - Multipath IO and load balancing (MPIO)
 - Array workload profile (sequential / random) and utilization at time of snapshot
 - ESXi hardware and resource utilization at time of snapshot
 - Virtual machine utilization and resource shares
 - VMFS Datastore resource shares
 
 
Additional Information
Recommendations :
- Ensure environment meets best practices
    
- VMware Configuration Guide for E-Series SANtricity iSCSI Integration with ESXi 6.xand 7.x Solution Design
 - E-Series and EF-Series Reference Architecture and Storage Best Practices with Veeam Backup & Replication
 - Perform iSCSI-specific tasks
 - Configuring the switches - iSCSI, VMware
 - Performance Degradation with Data Assurance enabled Volumes and iSCSI
 
 - Profiling and sizing the system performance
 - VMware Resources
 - Veeam Resources
 
