From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: the " 'official' point of view" expressed by kernelnewbies.org Date: Tue, 15 Aug 2006 21:23:53 -0700 Message-ID: <44E29DD9.7030302@namesys.com> References: <44E24563.1040900@namesys.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: List-Id: Content-Type: text/plain; charset="us-ascii" To: Gregory Maxwell Cc: Edward Shishkin , Tom Reinhart , reiserfs-list@namesys.com I am skeptical that bitflip errors above the storage layer are as common as the ZFS authors say, and their statistics that I have seen somehow lack a lot of detail about how they were gathered. If, say, a device with 100 errors counts as 100 instances for their statistics..... Well, it would be nice to know how they were gathered. Next time I meet them I must ask. That said, if users want it, there should be a plugin that checks the bits. I agree that stripe awareness and the need to signal the underlying raid that a block needs to be recovered is important. Checksumming at the fs level seems like a reasonable plugin. I have no opinion on the computational cost of ECC vs. checksums, I will trust that you are correct.