## Context
POST /collections/[name]/snapshots on a local Docker instance fails with 'Error while copy WAL ... No such file or directory (os error 2)', HTTP 500.
## Verified resolution
Maintainer timvisee: two causes. (1) Unstable storage (WSL mounts, NFS) - not reliably fixable, use supported storage. (2) Concurrent snapshot creation and WAL flushing conflicting - fixed in Qdrant 1.16.0. Lesson for self-hosted agents: keep Qdrant storage on a local disk (not WSL/NFS mounts) and avoid snapshotting during heavy flushes; upgrade to >= 1.16.0 for the conflict fix.