PowerProtect Data Manager 19.14 Virtual Machine User Guide

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Transparent Snapshots Data Mover performance and scalability

Review the following information related to performance considerations to scale your environment.

NOTE:As a VMware infrastructure best practice, it is recommended that you spread the workload across ESXi servers as much as possible. With the Transparent Snapshots Data Mover (TSDM) protection mechanism, you can move backup data in streams from multiple ESXi servers.

Table 1. Scalability limits for the vCenter and ESXi server
Component	Maximum limit
Number of protected virtual machines per ESXi server	Unlimited
Number of protected VMDKs per ESXi server	1,000
Number of protected VMDKs per virtual machine	40
Size of VMDK	64 TB
TSDM virtual machine backups	Embedded VM Direct Engine: up to 3,000 virtual machine backups, and up to 180 concurrent virtual machine backups. External VM Direct Engine: up to 5,000 virtual machine backups, and up to 300 concurrent virtual machine backups. NOTE:An external VM Direct Engine is not required when using TSDM as the protection mechanism for crash-consistent virtual machine protection and SQL application-aware protection.

Table 2. TSDM maximum concurrent protection operations and memory consumption
Component	Maximum limit	Notes
Number of concurrent virtual machine backups per ESXi host (ESXi and vCenter 7.0 U3d and later)	18	To obtain the maximum concurrent operations, the ESXi hosting the protected virtual machines must be version 7.0 U3d or later. This maximum is based on improvements to TSDM performance that result in faster processing of these sessions, and will vary based on the type of operations being performed (for example, single disk vs multiple disk virtual machine backups). NOTE:A lower number of concurrent streams helps to avoid over-subscription to the ESXi host memory.
Number of concurrent virtual machine restores per ESXi host (ESXi and vCenter 7.0 U3d and later)	16
Total number of concurrent virtual machine backups and restores per ESXi host (ESXi and vCenter 7.0 U3d and later)	20
Number of concurrent virtual machine backups per ESXi host (ESXi and vCenter 7.0 U3c)	10	This maximum is based on improvements to TSDM performance that result in faster processing of these sessions. Also, a lower number of concurrent streams helps to avoid over-subscription to the ESXi host memory.
Number of concurrent virtual machine restores per ESXi host (ESXi and vCenter 7.0 U3c)	10
Concurrent VMDK backups	Up to 28 disks	A full synchronization uses 29 MB/disk; a delta synchronization uses 9 MB/disk. 256 MB/9 MB per disk=up to 28 VMDK backups in parallel. For a single virtual machine, as an example, there might be a maximum of four parallel VMDKs per virtual machine during a full synchronization, and a maximum of 10 parallel VMDKs per virtual machine during a delta synchronization. NOTE:Depending on the combination of full and delta synchronizations and their respective memory consumption, 28 parallel VMDK backups is not always possible.
Total TSDM memory consumption on ESXi host	Up to 768 MB	256 MB/9 MB per disk=up to 28 VMDK backups in parallel.
TSDM memory consumption on ESXi host for DD streams	Up to 256 MB Up to 28 streams	A full synchronization uses 29 MB/disk; a delta synchronization uses 9 MB/disk. 256 MB/9 MB per stream=up to 28 DD streams in parallel. NOTE:Depending on the combination of full and delta synchronizations and their respective memory consumption, 28 streams is not always possible.