The maximum number of virtual machines varies by Synology NAS models (Refer to this article to know how many virtual machines can be run on a Synology NAS)
Supports up to 7 Synology NAS in a cluster
Privilege control for each virtual machine
Easy sharing of and access to virtual machines via browser URLs
Real-time CPU, memory, and network usage monitoring
Supports virtual machine instant clone within seconds
Supports virtual machine suspension and resumption
Supported image types:
Virtual DSM: *.pat
ISO: *.iso
Disk: *.img, *.vmdk, *.vdi, *.vhd, *.vhdx, and *.qcow2
Supports exporting a virtual machine as an OVA file
Schedulable snapshots for each virtual machine
Maximum number of snapshots per virtual machine: 32 (255 with a VMM Pro license)
Maximum number of snapshots per host: 65,536
Supports file-system consistent snapshots (Synology Guest Tool required on the guest OS)
Maximum number of virtual switches: 4 (4,096 with a VMM Pro license)
Maximum share links per host: 2 (16 with a VMM Pro license)
Virtual machine specifications
CPU
Compatibility mode for live migrations when CPUs on two hosts are different
Hyper-V Enlightenments function for I/O performance optimization
Virtual machine priority for CPU resource reservation
The maximum number of virtual CPUs varies by Synology NAS models
RAM
Minimum RAM
Virtual machine: 128 MB
Virtual DSM: 1 GB
The maximum number varies by Synology NAS models
Disk
Supported disk controller: IDE, SATA, VirtIO
Maximum number of disks per virtual machine/Virtual DSM: 8
Supports storage Quality of Service (QoS) with virtual machine priority
Supports maximum and minimum IOPS for each virtual disk