Re: Online verification of checksums
От | Fabien COELHO |
---|---|
Тема | Re: Online verification of checksums |
Дата | |
Msg-id | alpine.DEB.2.21.1809261703520.22248@lancre обсуждение исходный текст |
Ответ на | Re: Online verification of checksums (Michael Banck <michael.banck@credativ.de>) |
Список | pgsql-hackers |
>> The patch is missing a documentation update. > > I've added that now. I think the only change needed was removing the > "server needs to be offline" part? Yes, and also checking that the described behavior correspond to the new version. >> There are debatable changes of behavior: >> >> if (errno == ENOENT) return / continue... >> >> For instance, a file disappearing is ok online, but not so if offline. On >> the other hand, the probability that a file suddenly disappears while the >> server offline looks remote, so reporting such issues does not seem >> useful. >> >> However I'm more wary with other continues/skips added. ISTM that skipping >> a block because of a read error, or because it is new, or some other >> reasons, is not the same thing, so should be counted & reported >> differently? > > I think that would complicate things further without a lot of benefit. > > After all, we are interested in checksum failures, not necessarily read > failures etc. so exiting on them (and skip checking possibly large parts > of PGDATA) looks undesirable to me. Hmmm. I'm really saying that it is debatable, so here is some fuel to the debate: If I run the check command and it cannot do its job, there is a problem which is as bad as a failing checksum. The only safe assumption on a cannot-read block is that the checksum is bad... So ISTM that on on some of the "skipped" errors there should be appropriate report (exit code, final output) that something is amiss. -- Fabien.
В списке pgsql-hackers по дате отправления: