Undo Command Mac: A Glimpse into Filesystem Snapshots and Data Recovery

When it comes to file management, few tasks are as frustrating as accidentally deleting a crucial file or folder. Fortunately, Linux-based operating systems offer some relief in the form of filesystem snapshots, which provide a 'save point' that can be restored at any time. However, this feature is not inherent to the operating system or file system itself but rather a GUI tool with a functionality called 'delete' that does not actually delete files.

In contrast to graphical frontends, most Linux systems default to moving files to a trash directory when deleted. This is similar to other operating systems like Windows, where deleted files are also irretrievable by default. However, in the Linux world, when you delete something, it's often immediately overwritten by new data for efficiency.

FAT32 and NTFS file systems store some header information with the files themselves, making it easier to identify what files a set of blocks belong to (as long as that space hasn't been reclaimed by newer files yet). This varies from file system to file system (ext4, jfs, xfs, etc.), but these lists of blocks can usually address file sizes ranging from 2GB to several TB.

When a file is erased, there is no way to reference inodes on disk to what meta-data they use to belong. The 8th and 9th go to lists of inodes (doubly linked blocks) and the 10th goes to a list of lists of lists (tripply linked blocks). Typically, most filesystems allocate 10 blocks to a file in this meta-area. File meta-information is all stored in the front of the disk with references to inodes on the rest of the disk.

The reason Linux/Unix systems don't have an undelete stems from the way most filesystems store their information. This lack of undo functionality may be frustrating for users, but it's a fundamental aspect of how file systems work. Nevertheless, there are still ways to recover deleted files using specialized tools and techniques.

Undo command mac