On 11/24/16 02:03, Rebecca Cran wrote: > On 11/23/16 1:11 PM, Laszlo Ersek wrote: > >>>> Separately, a small note on ext4 (because you mention it above). I >>>> seem to recall a filesystem expert colleague of mine advise >>>> *against* using journaled filesystems for booting with e.g. grub2. >>>> The argument goes (if I recall right), XFS is considered to be in >>>> clean state if the data has made it to the final location *or* the >>>> persistent journal. When you cleanly unmount (or remount r/o) and >>>> shut down, the journal will be flushed to the final location, so a >>>> boot loader that doesn't know about the journal will read consistent >>>> data. However, if you crash *without* data loss, then part of the >>>> data might be in the journal only, and only clients that can read >>>> the journal will see consistent data. >>>> >>>>> This might or might not be >>>>> an issue, depending on what the point of the exercise is. > > > The problem of course is that "reset" (reboot), "reset -s" (shutdown) > etc. don't have any hooks a driver can use to flush data, so there will > sometimes (depending on how long ago data was written) be an unclean > unmount. At least when booting an OS there's an ExitBootServices event > available to make sure any data is flushed before boot services ends.
Related: https://bugzilla.tianocore.org/show_bug.cgi?id=224 > Though I've seen one person talking about how there at least used to be > a bug that means ExitBootServices isn't/wasn't called for one OS. > _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
