Hi, On 2018-04-11 19:32:21 -0700, Andres Freund wrote: > And there's cases where that just doesn't help at all. Being able to > untar a database from backup / archive / timetravel / whatnot, and then > fsyncing the directory tree to make sure it's actually safe, is really > not an insane idea. Or even just cp -r ing it, and then starting up a > copy of the database. What you're saying is that none of that is doable > in a safe way, unless you use special-case DIO using tooling for the > whole operation (or at least tools that fsync carefully without ever > closing a fd, which certainly isn't the case for cp et al). And before somebody argues that that's a too small window to trigger the problem realistically: Restoring large databases happens pretty commonly (for new replicas, testcases, or actual fatal issues), takes time, and it's where a lot of storage is actually written to for the first time in a while, so it's far from unlikely to trigger bad block errors or such. Greetings, Andres Freund
