Here is the script to check server’s disk size and space.
##checkspace.ps1
Function checkspace([string] $Hostname)
{
get-wmiobject -class win32logicaldisk -computername $Hostname `
| select DeviceID,@{name=”FreeSpace(GB)”;Expression={“{0,8:0.00}” -f ($.FreeSpace/1GB)}},`
@{name=”Size(GB)”;Expression={“{0,8:0.00}” -f ($_.Size/1GB)}}
}