AdvFS uses a relatively advanced concept of a storage pool (called a
file domain) and of logical file systems (called
file sets). A file domain is composed of any number of
block devices, which could be
partitions,
LVM or
LSM devices. A file set is a logical file system created in a single file domain. Administrators can add or remove volumes from an active file domain, providing that there is enough space on the remaining file domain, in case of removal. This was one of the trickier original features to implement because all data or
metadata residing on the disk being removed had to first be migrated, online, to other disks, prior to removal. File sets can be balanced, meaning that file content of file sets be balanced across physical volumes. Particular files in a file set can be
striped across available volumes. Administrators can take a
snapshot (or
clone) of any active or inactive file set. This allows for easy on-line backups and editing. Another feature allows administrators to add or remove block devices from a file domain, while the file domain has active users. This add/remove feature allows
migration to larger devices or migration from potentially failing hardware without a system shutdown.
Features Its features include: • a
journal to allow for fast crash recovery •
undeletion support • high performance • dynamic structure that allows an administrator to manage the file system on the fly • on the fly creation of snapshots • defragmentation while the domain has active users Under Linux, AdvFS supports an additional ‘’syncv’’ system call to atomically commit changes to multiple files. == History ==