On Tuesday, December 22, 2020 4:54:34 PM EST Matthew Almond via devel wrote:
> I currently download once and upgrade three different systems
by
> rsync-ing the cache.
>
> Do I understand that this will no longer be supported or work?
That's an interesting question. Is sharing the cache directory from
a single host intended to be shared like this? I am guessing no, but
it may still be common.
It should still work, with two caveats:
1. The files in the cache will be bigger, so a simple rsync will
involve more I/O, and the destination filesystem will also need more
space and I/O time.
2. The systems must be the same endianness (The transcoded format
doesn't bother with network order, because it's not intended to be
shared)
3. The page size must be the same for reflinking to work: This is
actually worked out when the filesystem is created, and defaults to
the system page size, and if not the same as the current page size,
the filesystem isn't even guaranteed to mount (see --sectorsize
option in mkfs.btrfs man page).
In reality you're quite unlikely to share packages unless the
architecture were the same, which would steer both endianness and
page size to the same value. That said, I'm aware that aarch64 can
be flexible in both ways. I'm covering my bases with my statement: I
have thought about it, and don't think I'm in any position to make
promises.
For this proposal: we're talking about shipping the code that would
allow this to be turned on. We're not talking about enabling it by
default. We can't until we have good answers to questions like this.
Understood.
To be clear, all three systems are x86_64, identical endianness,
architecture, and page size (as far as I know).
Also, this isn't a big deal, really. I just wanted to reduce network
bandwidth without operating a local mirror.
_______________________
sudo rsync -a --password-file=/etc/rsync.password --delete rsync://rsync@vfr/dnf
/var/cache/dnf;sudo dnf --enablerepo=updates-testing upgrade
--
Garry T. Williams