How Virtual Machines Access Storage. Virtual machines use virtual disks for their operating system, application software, and other data files. A virtual disk is stored as a VMDK file on a datastore. The virtual disk hides the physical storage layer from the virtual machine’s operating system. Regardless of the type of storage device that your host uses, the virtual disk always appears to the virtual machine as a local SCSI device.
https://pubs.vmware.com/vsphere-50/topic/com.vmware.wssdk.pg.doc_50/PG_Ch8_Storage.10.3.html
SR‐IOV supports up to 43 virtual functions on supported Intel NICs and up to 64. virtual functions on supported Emulex NICs. The actual number of virtual functions. available for passthrough depends on the number of interrupts vectors required by. each of them and on the hardware configuration of the host. Each ESXi host has a. limited number of interrupt vectors.
http://www.vmware.com/pdf/vsphere5/r55/vsphere-55-configuration-maximums.pdf
It's not really a matter of how many, but the size you need to look at... We create datastores between 500GB and 800GB which is suitable for us, sometimes we may create a supersize LUN/datastore for large VMs.
https://www.experts-exchange.com/questions/28501326/maximum-recommended-VM-per-VMFS-datastore-on-vSphere-5-1.html
 “vCenter Server Maximums” on page 7.  “vCenter Server Extensions” on page 7.  “vCloud Director” on page 9.  “VMware vSphere Flash Read Cache” on page 9.  “VMware Virtual SAN” on page 9. The limits presented in this document can be affected by other factors, such as hardware dependencies.
http://www.vmware.com/pdf/vsphere5/r55/vsphere-55-configuration-maximums.pdf
Fair point Joe. Most environments I support are enterprise licence installations and have at least 100 VM's. Plus we use In-Guest iSCSI (and NCM) for SQL and Exchange so we'd soon run out of volumes on the array . As a general rule we have 10 SQL VM's per datastore and 15 max for general file and front end app servers. Only a guide and naturally one cap does not always fit all.
https://connect.nimblestorage.com/thread/1887
As a result, you can run operating systems that are not certified for specific storage equipment, such as SAN, in the virtual machine. When a virtual machine communicates with its virtual disk stored on a datastore, it issues SCSI commands.
https://pubs.vmware.com/vsphere-50/topic/com.vmware.wssdk.pg.doc_50/PG_Ch8_Storage.10.3.html
It's like do not stack all your eggs in one basket, the larger the datastore, the more chance you are likely to have many VMs per datastore, and if there is corruption in the datastore or LUN, you will have many VMs lost. On average we have between 10 - 20 VMs per datastore.
https://www.experts-exchange.com/questions/28501326/maximum-recommended-VM-per-VMFS-datastore-on-vSphere-5-1.html
1 Assuming all hosts in a cluster see all luns, if you use a 1:1 ratio, you can't have more than 256 vms in a cluster. If you split OS/data vmdks on separate luns, your vm count goes down even more.  1:1 wastes space since every datastore has overhead, even thin provisioned.
https://connect.nimblestorage.com/thread/1887
A 1:1 ratio of VM's per datastore is impractical in the real world. If you are running hundred of VM's is carious VMware datacentres then you will very quickly consume all the array volumes 0-255.
https://connect.nimblestorage.com/thread/1887
Hi people, How many VM is there that is considered to be maximum per VMFS 5 datastore ? I couldn't find anywhere on VMware Maximums doco. I'm currently planning for the new VMFS datastore size and wondering about how big should I create the datastore. how do I know if the VMFS datastore is currently running too many VMs ?
https://www.experts-exchange.com/questions/28501326/maximum-recommended-VM-per-VMFS-datastore-on-vSphere-5-1.html
how many vm in vm datastore
There are 10 to 20 virtual machines in Virtual Machine datastore. There are 10 to 20 vms in the vm datastore.