> WAL mode requires shared access to System V IPC mapped memory.

Incorrect. It requires access to mmap()

"The wal-index is implemented using an ordinary file that is mmapped for robustness. Early (pre-release) implementations of WAL mode stored the wal-index in volatile shared-memory, such as files created in /dev/shm on Linux or /tmp on other unix systems. The problem with that approach is that processes with a different root directory (changed via chroot) will see different files and hence use different shared memory areas, leading to database corruption."

> This is unlikely to work across containers.

I'd imagine sqlite code would fail if that was the case; in case of k8s at least mounting same storage to 2 containers in most configurations causes K8S to co-locate both pods on same node so it should be fine.

It is far more likely they just fucked up the code and lost data that way...