On Thu, Mar 05, 2020 at 03:38:20PM +0100, Daniel Kiper wrote: > On Thu, Mar 05, 2020 at 06:40:01PM +0800, Michael Chang wrote: > > Further to the discussion about disabling btrfs zstd support for > > i386-pc[1], this paragraph in manual about mbr gap size doesn't seem to > > hold true any longer. > > > > "You must ensure that the first partition starts at least 31 KiB (63 > > sectors) from the start of the disk" > > > > As in many occasions we inevitablely have to provide core image size > > that goes beyond 31 KiB, this statement becomes a true liability as > > people would be misguided and think it is still fine to use small MBR > > gap, that has always been a headache in distribution's upgrade path as > > growing new feature would render the size requirement bigger but no way > > for the user to relocate their partitions. > > Could you split this paragraph into a few sentences? Now it does not > read very well...
OK. I'll come up with a better expression next version. > > > The patch tries to correct the paragraph with a more practical size that > > works for grub and also for modern computer systems in general. > > > > [1] https://lists.gnu.org/archive/html/grub-devel/2019-11/msg00025.html > > > > Signed-off-by: Michael Chang <mch...@suse.com> > > --- > > docs/grub.texi | 20 ++++++++++++++------ > > 1 file changed, 14 insertions(+), 6 deletions(-) > > > > diff --git a/docs/grub.texi b/docs/grub.texi > > index 83979af38..651468268 100644 > > --- a/docs/grub.texi > > +++ b/docs/grub.texi > > @@ -845,12 +845,20 @@ only be used if the @file{/boot} filesystem is on the > > same disk that the > > BIOS boots from, so that GRUB does not have to rely on guessing BIOS drive > > numbers. > > > > -The GRUB development team generally recommends embedding GRUB before the > > -first partition, unless you have special requirements. You must ensure > > that > > -the first partition starts at least 31 KiB (63 sectors) from the start of > > -the disk; on modern disks, it is often a performance advantage to align > > -partitions on larger boundaries anyway, so the first partition might start > > 1 > > -MiB from the start of the disk. > > +The GRUB development team generally recommends embedding GRUB before the > > first > > +partition, unless you have special requirements. You must ensure that the > > first > > +partition starts at least 1 MiB from the start of the disk; on modern > > disks, it > > s/; on modern disks, it/. Additionally, on modern disks it/ OK. > > > +is often a performance advantage to align partitions on larger boundaries > > and 1 > > +MiB is the least common multiple of many used alignment sizes. For SSD, it > > s/For SSD, it/E.g. SSD, it/ OK. > > > +became crucial to have the partition correctly aligned to avoid excessive > > +read-modify-write cycles and thus modern tools set to use 1 MiB as a > > stardard > > +practice. > > + > > +In case legacy systems that cannot boot if first partition not on the > > cylinder > > s/In case legacy/In case of legacy/ > s/partition not/partition is not/ OK. > > > +boundary, the fallback blocklist install method should remain working for > > them > > +if the core image growing too much someday. Here we just can't advertise > > that > > +31 KiB (63 sectors) is a sensible size any longer as that would pose great > > +constraint to include new features as time goes by. Thanks a lot for taking time to review. Regards, Michael > > Daniel > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > https://lists.gnu.org/mailman/listinfo/grub-devel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
