Run the below script to get all VMs of all vCenters with Snapshot details :
$vm_snapshot = @()
$vm_consolidate = @()
$vc = get-content d:\snapshot\serverlist.txt
foreach ( $vcs in $vc)
{
connect-viserver $vcs
$VMs = get-vm
$vm_consolidate += $VMs | get-harddisk | select @{ n = "Virtual Center";e= { (($_.uid).split("@")[-1]).split(":")[0] }}, Parent,name,StorageFormat,Filename
$vm_snapshot += $VMs | get-snapshot | sort created |select @{"N" ="VirtualCenter";"E" = {$vcs}},VM,name, @{"N" ="Created";"E" = {$_.created.tostring("d")}}, description, sizeMB, powerstate
disconnect-viserver $vcs
}
$vm_consolidate | export-csv d:\snapshot\diskinfo.csv
$vm_snapshot | export-csv d:\snapshot\snapshotsinfo.csv