Does your Mac system show error messages while operating? Are you searching for the better HFS undelete procedure? If so, then you are on the right way. In order to keep our data safe and more secure, you may go for partitioning entire HFS volume to several small fragments. But, while doing so, many a time HFS file systems become unmounted and start giving several error messages like “unable to mount HFS volume”, “Mac volume not mounted”, etc. which further lead for HFS undelete issue. However, due to the occurrence of such panic situation users are not being able to access any of their stored data from Mac HFS volume. Now you are bothered to know about some of the common causes that are quite responsible for the emergence of HFS undelete issue. If so, then let's have a look. The problem with the HFS volume generally appears due to improper shutting down of the Mac system, deleting some important Mac files, improper Mac volume partitioning, etc. Now, in order to perform an HFS undelete procedure, there are various of methods available such as trying disk utility, going through the terminal and using FSCK command or even trying to re-install the Mac OS X.