Does vault kv metadata delete command follow NIST PURGE standards?

NIST purge refers to a physical or logical technique that renders target data recovery infeasible using state-of-the-art laboratory overwrite, block erase, and cryptographic erase methods.

Which command does vault kv metadata delete internally use to delete the data?

Vault is just removing the records from the storage engine, so it depends on which storage engine you are using for what actually happens. For example if you are using a database it is probably just removing rows from a few tables. All data is stored encrypted, so it should still be secure, but I’d imagine nothing will be acting on block level to erase or cryptographically override the storage.

I’m using file storage as the storage backend. Is there any way to purge the data?