On 2016-05-03 T 19:02 +0200 Daniele wrote:
Il 03/05/2016 18:57, Richard Brown ha scritto:
On 3 May 2016 at 18:50, Daniele <kailed@kailed.net> wrote:
Il 03/05/2016 11:57, Yamaban ha scritto:
Next TW-upgrade comes: User calls zypper dup 1. zypper will snapshot (pre update), 2. zypper downloads all the packages (this takes extra space not needed later, if the packages are not kept), and installs them, 3. second snapshot (post update) happens.
The second snapshot is big, as it contains all the changed / added files.
Hi, is the second snapshot really needed ? I think that is useful only in some corner case..
Daniele.
As these are COW snapshots there is no additional space used from the second snapshot compared to the running system at that time.
But is big compared to the previous one or not ? Anyway, what is for ?
As described above, the first snapshot is the status "BEFORE Update" also called "pre". The second snapshot determines the status directly AFTER the update, also called "post". Directly after this snapshot, the status of the updated system starts changing. The primary purpose of snapshots is, though, to ever have a point to "jump back to", also known as "well known state". If there would not be a (second) snapshot directly after the update, your only "well known state" would be _before_ the update, and this is not necessarily what you want to have. As Richard said, a snapshot, where there is no CoW action involved costs basically nothing; exactly it is 12 KiB (3 blocks), if I am not mistaken. Thus taking the second snapshot is a good choice. ---- Now, back to the topic of "free space" (or more precisely lack thereof): Reading the above, I wonder, if we may have a race condition in the ZYpp stack, where the downloaded packages are deleted _after_ the second snapshot. This indeed would explain: - Why the second snapshot _is_ huge - Why Tumbleweed users have a more pressing space issue than e.g. SLE 12 users (such as myself). So long - MgE -- Matthias G. Eckermann, Director Product Management SUSE Linux Enterprise SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org