Are you wondering how you can perform data recovery from no mountable file system ? The problem of no mountable file system occurs with the dmg file that is required to install any application or software in the Mac. So you will be unable to install it without rectifying the issue which is causing because either the dmg file or the drive where you are trying to mount has gone corrupted. You can try to get the fresh copy of the file or if the drive is corrupted then fix it using the disk utility. You may also have to format the drive then you can do the data recovery from no mountable file system by using the time machine backup. But if the time machine is not helping then you can use the Mac data recovery software to scan the formatted drive and restore all the files by selecting them from the preview. You will be able to recover almost any type of file. So you must download the software now and accomplish data recovery from no mountable file system in an easy way.