PowerProtect Data Manager 19.11 Virtual Machine User Guide

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Transparent Snapshot 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 Snapshot Data Mover 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	1000
Size of VMDK	64 TB
Transparent Snapshot Data Mover (TSDM) backups	Up to 3000 virtual machine backups, and up to 180 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. For application consistent and application aware virtual machine protection, add a VM Direct Engine.

Table 2. TSDM maximum concurrent protection operations and memory consumption
Component	Maximum limit	Notes
Number of concurrent virtual machine backups per ESXi host	10	The 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	10
Concurrent VMDK backups	Up to 28 disks	A full sync uses 29 MB/disk; a delta sync 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 sync, and a maximum of 10 parallel VMDKs per virtual machine during a delta sync. NOTE Depending on the combination of full and delta syncs and their respective memory consumption, 28 parallel VMDK backups is not always possible.
TSDM memory consumption on ESXi host	Up to 768 MB
TSDM memory consumption on ESXi host for DD streams	Up to 256 MB Up to 28 streams	A full sync uses 29 MB/disk; a delta sync 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 syncs and their respective memory consumption, 28 streams is not always possible.