On Mon, Mar 17, 2025 at 11:32:21AM -0600, Keith Busch wrote: > I'm not even sure it makes sense to suspect the controller side, but the > host side is considered reliable? If the media is in fact perfect, and > if non-FUA read returns data that fails the checksum, wouldn't it be > just as likely that the transport or host side is the problem?
>From the error numbers we've seen it would in fact be much more likely to be the host or transport side. > Every > NVMe SSD I've developered couldn't efficiently fill the PCIe tx-buffer > directly from media (excluding Optane; RIP), so a read with or without > FUA would stage the data in the very same controller-side DRAM. Exactly. It's an writeback+invalidate+reread operation. A great way to slow down the read, but it's not going to help you with data recovery.
