hesela.devFilesystem freeze
A filesystem freeze temporarily blocks modifications after completing ongoing filesystem transactions and flushing dirty filesystem data, metadata and logs to storage.
Linux fsfreeze requires a mounted filesystem with freeze support; blocked modifications resume after thaw. [1] QEMU v10.1.0 freezes eligible local guest filesystems and returns a count, which may be zero; its list variant ignores invalid mountpoints. That count does not establish coverage of every application dependency. [2] Filesystem transactions are not application transactions: application preparation is a separate concern. [3]
Relations
- related
- snapshot, application-consistent-snapshot, application-quiescing, crash-consistency, restore-test
Advantages
- Can establish a stable filesystem image for snapshot-capable storage. [1]
Limitations
- Writers can remain blocked until thaw; a recovery procedure must account for failed capture and cleanup. [1]
- Files still undergoing unlink can remain represented in the frozen on-disk image until thaw or a clean mount of the snapshot completes. [1]
- A guest-agent status report can be invalidated by another process changing freeze state. [2]