Messages in this thread | | | Date | Tue, 26 Apr 2016 07:59:10 -0700 | Subject | Re: [PATCH v2 5/5] dax: handle media errors in dax_do_io | From | Dan Williams <> |
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On Tue, Apr 26, 2016 at 1:27 AM, Dave Chinner <david@fromorbit.com> wrote: > On Mon, Apr 25, 2016 at 09:18:42PM -0700, Dan Williams wrote: [..] > It seems to me you are focussing on code/technologies that exist > today instead of trying to define an architecture that is more > optimal for pmem storage systems. Yes, working code is great, but if > you can't tell people how things like robust error handling and > redundancy are going to work in future then it's going to take > forever for everyone else to handle such errors robustly through the > storage stack...
Precisely because higher order redundancy is built on top this baseline.
MD-RAID can't do it's error recovery if we don't have -EIO and clear-error-on-write. On the other hand, you're absolutely right that we have a gaping hole on top of the SIGBUS recovery model, and don't have a kernel layer we can interpose on top of DAX to provide some semblance of redundancy.
In the meantime, a handful of applications with a team of full-time site-reliability-engineers may be able to plug in external redundancy infrastructure on top of what is defined in these patches. For everyone else, the hard problem, we need to do a lot more thinking about a trap and recover solution.
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