Just read a excellent and very comprehensive article about VMware vSphere VM quiescing. This is the necessary process - within a VM - to get a consistent status of the guest OS (especially virtual disk) and applications. So VM gets quiesced before vSphere snapshot is created. Because VBR uses (like I think any other backup software vendor) vSphere snapshots for backup/replication, I thought this article would be interesting to share. It is definitely worth reading and I highly recommend to do so!
https://blog.zuthof.nl/2020/11/26/vsphere-vm-quiescing-essentials/
Here a short overview:
- What is quiescing?
- Consistency options
- Non-quiesced
- Crash consistent
- Quiesced
- File-system consistent
- Application consistent
- Interfaces Veeam uses
- Network (RPC)
- vSphere VIX
- Usage in
- Windows
- VSS
- Script
- Linux
- Script
- Windows
- Quiescing impact on app recovery
- Transaction Logs
- Interfaces Veeam uses
- Non-quiesced
- Quiescing impact on performance
- Snapshot based
- Impact because of vSphere snapshot
- Less impact with Storage snapshots (supported by Veeam)
- IO Filter (VAIO)
- For replication
- in v10: Replication also uses vSphere Snapshots
- in v11: CDP uses vSphere IO Filter as well
- For replication
- Snapshot based
- The role of VMware Tools
- VMware Tools is its own product
- Tools are back- and forward-compatible
- Windows
- Use current versions
- Some driver are part of Windows Updates
- Linux
- Use open-vmware-tools