[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: btrfs compression by default



On Tue, Feb 9, 2021 at 12:26 PM Chris Murphy <lists colorremedies com> wrote:
>
> On Tue, Feb 9, 2021 at 11:40 AM Martin Kolman <mkolman redhat com> wrote:
> >
> > On Tue, 2021-02-09 at 09:50 -0700, Chris Murphy wrote:
> > > On Tue, Feb 9, 2021 at 9:15 AM Michel Alexandre Salim
> > > <michel michel-slm name> wrote:
> > > > There's a further complication: Chris just informed me that on BIOS
> > > > systems, space is more of a constraint so the zstd module is not part
> > > > of GRUB ... meaning we have to handle these two scenarios:
> > >
> > > It's available, but it's the 2nd largest GRUB module at ~100KiB. And
> > > on BIOS we're space limit right now to 1 MiB MBR gap or BIOS Boot
> > > partition.
> > >
> > > GRUB works fine with a zstd compressed /boot/ but obviously there's
> > > next to no benefit compared to the added complexity since the kernel
> > > and initramfs are already compressed.
> > >
> > > So if it's not difficult to exclude compression on /boot/ that's
> > > probably preferred?
>
> > Are we talking about custom partitioning layouts ?
>
> For Fedora 34, yes. There's an idea/pre-plan for Fedora 35/36 to put
> /boot/ on Btrfs by default; but it's contingent on GRUB changes needed
> upstream to better support grubenv by putting it on a dedicated
> partition. [1]

:D

[1]
GRUB disallows writes to it from the pre-boot environment when grubenv
is on mdadm, luks, btrfs, zfs; while GRUB allows writes to grubenv
when on ext[234] and XFS the fs developers really frown on anything
other than kernel code writing to a file system owned partition, even
if that write is just a data block overwrite. So the idea is to stop
doing it and give grubenv it's own partition sorta like BIOS Boot.


-- 
Chris Murphy


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]