On Aug 27, 2019, at 1:10 PM, dann frazier <dann.frazier@xxxxxxxxxxxxx> wrote: > > hey, > I'm curious if there's a policy about what types of unclean > shutdowns 'e2fsck -p' can recover, vs. what the kernel will > automatically recover on mount. We're seeing that unclean shutdowns w/ > data=journal,journal_csum frequently result in invalid checksums that > causes the kernel to abort recovery, while 'e2fsck -p' resolves the > issue non-interactively. The kernel journal recovery will only replay the journal blocks. It doesn't do any check and repair of filesystem correctness. During and after e2fsck replays the journal blocks it still does basic correctness checking, and if an error is found it will fall back to a full scan. > Driver for this question is that some Ubuntu installs set fstab's > passno=0 for the root fs - which I'm told is based on the assumption > that both kernel & e2fsck -p have parity when it comes to automatic > recovery - that's obviously does not appear to be the case - but I > wanted to confirm whether or not that is by design. The first thing to figure out is why there are errors with the journal blocks. That can cause problems for both the kernel and e2fsck journal replay. Using data=journal is not a common option, so it is likely that the issue relates to this. IMHO, using data=journal could be helpful for small file writes and/or sync IO, but there have been discussions lately about removing this functionality. If you have some use case that shows real improvements with data=journal, please let us know. Cheers, Andreas
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