Issymlink

Issymlink is a term used to describe a proposed mechanism for creating and managing symbolic links in a way that preserves target integrity across networked and mutable file systems. Unlike traditional symlinks, issymlinks carry additional metadata that validates the link's target and can offer fallbacks when targets are moved or renamed. The concept arose in discussions of distributed file systems and large-scale deployments where links frequently break during data migration.

Design goals include resilience to path changes, cross-volume resolution, and security against link spoofing. An issymlink consists of a link record that stores the link name, the declared target path, a cryptographic hash of the target, a version or namespace identifier, and metadata such as creation time and user permissions. Implementations typically use extended attributes or a small accompanying sidecar file to store this data, with resolvers that verify the hash before following the link.

Usage typically involves a dedicated tool or library that can create issymlinks, resolve them, or repair broken ones automatically. Operations include creating an issymlink with a specified target, resolving to determine the current valid target, and, if necessary, re-targeting affected links automatically.

Adoption is limited and experimental; there is no formal standard. Prototypes exist in academic projects and some open source distributed file systems, but broad compatibility with existing POSIX interfaces remains a challenge. Potential benefits include reduced maintenance of references in dynamic environments and improved consistency across snapshots and backups.

See also symbolic link, hard link, extended attributes, distributed file system.