On Tue, 21 Mar 2017, Thorsten Kukuk wrote:
On Tue, Mar 21, Richard Biener wrote:
On Tue, 21 Mar 2017, Thorsten Kukuk wrote:
On Tue, Mar 21, Richard Biener wrote:
So what issue are we solving then? That is, is this for CaaSP only where we can guarantee the r/o root?
The problems we want to solve are all the broken systems you can regular read on the factory list about after an update, because the update in the running system did break other running processes. Especially the Desktop.
Sure. But do we now exchange this for all the broken systems where replacing root with the snapshot after the transaction? And are we sure the number of broken systems will actually shrink with this change? (and can you prove that?)
Sorry, but I neither understand what you are writing here nor what your problem is.
What I can prove is: all the problems the people had with updates, that their running applications did crash and the update did not finish and their system were left over in a unbootable state can be solved with this.
True - this is because you are not updating the running system but the one that is activated after the next reboot (as far as I understand).
And about your fear about that the snapshot is in a broken state after update even if zypper did not return any error: if this happens, this would also happen with your normal running system. It does not matter if you update a snapshot or the real system, the installed RPMs are the same.
No, I am refering to the time window between creating the snapshot and activating it. For a true transaction you'd need to verify the root you are about to replace with the updated snapshot is in the same state as at the time of snapshot creation (thus, it had better be readonly). Otherwise you are losing data.
And, don't forget: if you don't like transactional updates, nobody is forcing you to use them.
Of course. But the system you are implementing sounds a more dangerous way of effectively downloading the update in the running system, rebooting, and at defined state (say, in initrd context) create the snapshot, install into it and continue booting from it. _Without_ the issue of that inconsistency due to the time window the root is active between creating the snapshot and activating it. Richard.
Thorsten
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Richard Biener