Brooks

Is this an issue because with the CLI flag we create the PDA account, thus producing a different bank hash because the rest of the cluster does not have this...

> Yeah. Exactly. Great! Then yes, this idea looks safe to me. We already do the same thing for the sysvar accounts, so also ignoring another account makes sense.

Firstly, thanks for the investigation and writeup work here @dnut! Here's some general thoughts after reading through the PR description and code, the DashMap code, and the current Secondary Index...

Hmm, seems brittle to depend on the ordering of errors to inform clients of Tiered Storage if this is tiered storage file or an append vec. What about instead having...

> > Since new_from_footer_block() takes in a TieredStorageFile, it seems like maybe the check should go there. > > Checking inside the `new_from_footer_block()` seems the option, and this PR does...

An additional note, currently the system cannot recover from this. Meaning subsequent reboots will keep hitting this panic (or the other one about invalid append vecs: https://github.com/solana-labs/solana/issues/35190). Luckily https://github.com/solana-labs/solana/pull/35350 will...

I rebased and force-pushed this branch to pull in #35307.

I rebased and force-pushed this branch to pull in #35307.

@HaoranYi @jeffwashington This PR is now ready for a re-review.

Rebased on top of #35336, so that I can use `get_account_info_with_and_then()` in the impl of this PR.