Hi, On Tue, 21 Mar 2017, Thorsten Kukuk wrote:
What happens e.g. in this situation:
% user installs update % user installs more updates % user adds repo and installs a new rpm foo % user reboots (because finally he's annoyed by the warning of having to reboot)
foo is gone from the rebooted system, right (except of course for the desktop item for that program, now pointing to a dead file, which is even more surprising)? Are at least updates 1 and 2 merged?
Nothing happend and foo is there, if the user only uses the transactional-update script and not a mix of different tools.
That's nice. Is zypper for installing the rpm at above third step a different tool for these purposes (and does it mean that the rpm is installed twice, once into the used-after-reboot snapshot, and once into the currently used one?)
But the way Windows does it (I don't know about GNOME) is definitely more like a proper transaction than installing into a snapshot and just activating it at next reboot over whatever was there before. That's not transactional at all because the abort-transaction with concurrent writes is missing.
Sorry, but exactly the other way around is true. Windows is not doing any transaction at all. If your system breaks, it's broken. What Windows calls "transaction" in this case is only what is written into the windows registry, not on harddisk.
Um. I'm not sure how to say this, but you do know that NTFS provides snapshots as well and Windows makes use of them for update purposes much similar to our rollback scenario with btrfs? And as the kernel-related updates for it are installed at points where there are definitely no other writers, namely at shutdown or bootup, yes, that is actually transactional (or at least more so, all this talk about "transactional" related to updates and filesystems is a bit dodgy as it's quite a bit unlike transactions in the database sense). That this is done in Windows had initially different reasons, but now the side-effect is that the updates are safe from concurrent writes. (that would be comparable to us installing the updates from initrd just after mounting the FSes)
Perhaps, are the slides somewhere?
Yes, in the Fosdem archive.
Looking. I'm still hoping I have some basic misunderstanding of the whole "transactional" updates idea. Ciao, Michael. -- To unsubscribe, e-mail: opensuse-packaging+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-packaging+owner@opensuse.org