recover

recover [-vNLaf] [-o output_dir] [-i inode_num] device [target_path]

device
    The path to the filesystem device (e.g., /dev/sda1) from which to recover files. This must be an unmounted partition.

target_path
    Optional. A specific path or filename within the filesystem being recovered to target for recovery. Can be a directory for recursive recovery or a specific file name.

-v
    Enable verbose output, displaying detailed information about the scanning and recovery process.

-N
    Perform a dry run. The command will simulate the recovery process and report what could be recovered without actually writing any data to the output directory.

-L
    List all identifiable recoverable inodes or files found on the device without attempting to recover them. Useful for previewing.

-a
    Attempt to recover all identifiable deleted files and place them into the specified output directory, organizing them by inode or file type.

-f
    Force recovery, even if some filesystem checks indicate potential issues or the filesystem is not cleanly unmounted (use with caution).

-o output_dir
    Specify the directory where recovered files will be placed. This directory must not be on the filesystem currently being recovered to prevent further data corruption.

-i inode_num
    Specify a particular inode number to recover. This is most effective when you know the exact inode of the deleted file, typically obtained from filesystem logs or specific analysis tools.

The recover command, typically found in older or specialized Linux environments, is a utility designed to undelete files from ext2 and ext3 filesystems. It operates by scanning the filesystem for orphaned inodes or unlinked directory entries that still contain file data. To minimize further data corruption, it is crucial to run recover on an unmounted filesystem. Success is highly dependent on whether the disk blocks occupied by the deleted file have been overwritten by new data. Due to the dynamic nature of disk usage, complete and perfect recovery is rarely guaranteed, especially for fragmented files. This tool is largely considered a legacy utility, having been superseded by more advanced forensic tools and filesystem-specific recovery utilities.

The recover command is not a standard, universally available utility on most modern Linux distributions. Its effectiveness is severely limited by several critical factors:
1. Data Overwriting: Any new data written to the disk after deletion can overwrite the blocks of the deleted file, making recovery impossible.
2. Filesystem State: For safe and effective recovery, the target filesystem must be unmounted and ideally accessed in read-only mode. Running on a mounted filesystem risks further data loss or corruption.
3. Fragmentation: Highly fragmented files are significantly more challenging to recover perfectly, as their data blocks may be scattered across the disk.
4. Filesystem Type: This utility is primarily designed for older ext2 and ext3 filesystems and is generally not suitable for modern filesystems like ext4, XFS, Btrfs, or ZFS.
5. Legacy Tool: For critical data recovery, consider more robust, actively maintained, and feature-rich tools such as extundelete, TestDisk, or forensic suites.

The recover utility, as described, emerged in the context of early Linux filesystems, primarily ext2 and later ext3, as a basic undeletion tool. It was often distributed as part of specific filesystem utilities or packages, sometimes associated with efforts like e2undel (though e2undel itself is a distinct tool). Its initial development aimed to provide a direct, albeit rudimentary, way to salvage accidentally deleted files by examining raw filesystem structures. However, with the evolution of Linux filesystems (e.g., journaling in ext3/ext4, advanced features in XFS/Btrfs) and the advent of more sophisticated data recovery and forensic analysis tools, the original recover command has largely become obsolete or niche. Modern data recovery often relies on filesystem-specific utilities, snapshotting capabilities, or byte-level disk imaging combined with specialized forensic software.

extundelete(8), debugfs(8), fsck(8), testdisk(8), photorec(8)