I want my media folder to be placed in another server My server has low space. So I need it to be placed in another server. Changing the media Url is not working. Somebody suggest some idea
Yes, it is possible to use a remote service in order to do that. I suggest you install a Magento ImageCDN plugin - https://www.magentocommerce.com/magento-connect/imagecdn.html
With this you can use one of the third party providers such as Amazon S3, or an FTP connection to a remote server.
You would need to setup Apache/Nginx on the server and have it serve those images eg media.yourdomain.com on http and https.