Hi Adrian,
On 21.06.20 09:11, Adrian Bunk wrote:
On Fri, Jun 19, 2020 at 03:35:33PM +0100, csimmonds wrote:
I would like to add that this is a design decision. Package updates, be
they based on rpm, deb, or ipk, are not atomic. Which means that if you
power off during an update the system will usually not boot afterwards.
This is not true, package manager like dpkg are trying very very hard to
make things atomic where they have to be and allow recovery from any
kind of interruption.
I agree with Chris. Yes, dpkg had a lot of improvements, and it is more
difficult to break a Debian / Ubuntu during an "apt-get update". But let
me say it is not enough for embedded systems.
I think you mean that dpkg has improved to make the update of a single
package more atomic, but what about if you upgrade a lot of packages at
once and you have a power-cut in between ?
If it can work in many case, it won't in many other cases. Hash issues
with packages ? System does not boot and a grub-rescue shell is started
? Not a very big problem (in many cases) on server / pc. We check what
happens, we rework maybe the grub menu, or if nothing works we start a
live distro. But if this is ok on server / pc for a linux developer, how
can it work on unattended (embedded) systems, without shell access (due
to security reasons), and with end users ? It is not enough if it works
in most cases, it must always work.
I do not recall anyone ever describing such a problem with Debian
(or Ubuntu) in over 20 years as Debian user/administrator/developer.
Yes, but if you say that we can update safe between two Debian / Ubuntu
versions, I have just a couple of cases on my desk that it could not
work without human intervention...
...
OpenEmbedded/Yocto
Project expect the update will be done by programming a new root
filesystem image.
...
Note that what you write would imply that package management must not
ever be used on OpenEmbedded/Yocto devices.
I do not think Chris thought this - you can use package management, it
speeds up the development process. How this is possible to be used in
field, it depends on specific situation (maybe just the application is
udated via package ?), but it is generally not thought to be atomic from
one distro version to another one (including downgrading).
If there is any potential problem, it would equally apply to the
situation where you are upgrading just one package for a security
update.
In fact, it could apply...
Best regards,
Stefano
HTH,
Chris
cu
Adrian
--
=====================================================================
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: [email protected]
=====================================================================
-=-=-=-=-=-=-=-=-=-=-=-
Links: You receive all messages sent to this group.
View/Reply Online (#49707): https://lists.yoctoproject.org/g/yocto/message/49707
Mute This Topic: https://lists.yoctoproject.org/mt/74978107/21656
Group Owner: [email protected]
Unsubscribe: https://lists.yoctoproject.org/g/yocto/unsub
[[email protected]]
-=-=-=-=-=-=-=-=-=-=-=-
