[yast-devel] Reusing volume groups in the new partition proposal
We are discussing here what to do when reusing an existing volume group in the new storage proposal and I would like to hear as many opinions as possible, as I don't know what is better. https://github.com/yast/yast-storage-ng/pull/111#discussion_r87795799 What the old (current) proposal does ==================================== (A longer version of this explanation including examples is available in a comment at https://trello.com/c/WbcaGFAo for those with access.) The old proposal only reuses a VG called "system". If such VG exists and is big enough, the required LVs will be created there. The previous LVs will not be touched if there is enough free space. Otherwise, as many LVs as needed will be deleted (not necessarily all of them). There is one special case. The proposal reuses (reformats) any LV named "root" (if it's big enough, I assume). What the code in yast-storage-ng#pr111 does =========================================== The new proposal decides which VG to reuse (if any) based on the size, not on the name. There is no reusing of LVs. The proposal simply deletes as many previous LVs as needed to make space for ours (it deletes none if there is enough free space already at the beginning). Pretty much like the old proposal does. What's under discussion ======================= Steffen suggested that we should always just delete all LVs when reusing an existing VG. At least in the case when we don't fit into the original free space. That would mean less logic to maintain, of course, but I wonder whether its a step backwards. So I guess the question is - does it makes sense to be conservative when deleting LVs (trying to delete as few as possible) or should we go directly all the way through? Cheers. -- Ancor González Sosa YaST Team at SUSE Linux GmbH -- To unsubscribe, e-mail: yast-devel+unsubscribe@opensuse.org To contact the owner, e-mail: yast-devel+owner@opensuse.org
On Monday 2016-11-14 18:10, Ancor Gonzalez Sosa wrote:
Steffen suggested that we should always just delete all LVs when reusing an existing VG. At least in the case when we don't fit into the original free space.
That would mean less logic to maintain, of course, but I wonder whether its a step backwards.
So I guess the question is - does it makes sense to be conservative when deleting LVs (trying to delete as few as possible) or should we go directly all the way through?
If you are thinking about typical setups, imagine you have an existing VG (say, from a previous suse install) with root+swap+home, no free space left in this VG. Lets assume home to be the biggest chunk. The new code will go looking for space, finds root too small (because we are looking for at least root+swap) and will propose to kill the old home and add a new set of root+home (possibly reusing the old swap). I think that would be unnecessarily fragmenting disk space and we'd be better off just killing all LVs and adding a new set of LVs (owning the whole VG). Steffen -- To unsubscribe, e-mail: yast-devel+unsubscribe@opensuse.org To contact the owner, e-mail: yast-devel+owner@opensuse.org
On Mon, Nov 14, 2016 at 06:30:02PM +0100, Steffen Winterfeldt wrote:
On Monday 2016-11-14 18:10, Ancor Gonzalez Sosa wrote:
Steffen suggested that we should always just delete all LVs when reusing an existing VG. At least in the case when we don't fit into the original free space.
That would mean less logic to maintain, of course, but I wonder whether its a step backwards.
So I guess the question is - does it makes sense to be conservative when deleting LVs (trying to delete as few as possible) or should we go directly all the way through?
If you are thinking about typical setups, imagine you have an existing VG (say, from a previous suse install) with root+swap+home, no free space left in this VG. Lets assume home to be the biggest chunk.
The new code will go looking for space, finds root too small (because we are looking for at least root+swap) and will propose to kill the old home and add a new set of root+home (possibly reusing the old swap).
I think that would be unnecessarily fragmenting disk space and we'd be better off just killing all LVs and adding a new set of LVs (owning the whole VG).
In the past people often complained about YaST deleting the home partition or logical volume. Those people would expect the proposal to reuse home and either delete and recreate or simply format root and swap. Why those people don't make an update I can only guess - bad experience with updates. ciao Arvin -- To unsubscribe, e-mail: yast-devel+unsubscribe@opensuse.org To contact the owner, e-mail: yast-devel+owner@opensuse.org
On Monday 2016-11-14 19:03, Arvin Schnell wrote:
In the past people often complained about YaST deleting the home partition or logical volume. Those people would expect the proposal to reuse home and either delete and recreate or simply format root and swap. Why those people don't make an update I can only guess - bad experience with updates.
Then it's maybe worth to change the strategy from looking for a single large free blob that's later split into root/swap/home to looking for 3 closely matching blobs for root/swap/home (for example). This might ideally lead to reusing the corresponding existing volumes. Steffen -- Give orange me give eat orange me eat orange give me eat orange give me you. (chimp Nim, using sign language) -- To unsubscribe, e-mail: yast-devel+unsubscribe@opensuse.org To contact the owner, e-mail: yast-devel+owner@opensuse.org
On Mon, 14 Nov 2016 18:10:34 +0100 Ancor Gonzalez Sosa <ancor@suse.de> wrote:
We are discussing here what to do when reusing an existing volume group in the new storage proposal and I would like to hear as many opinions as possible, as I don't know what is better. https://github.com/yast/yast-storage-ng/pull/111#discussion_r87795799
What the old (current) proposal does ==================================== (A longer version of this explanation including examples is available in a comment at https://trello.com/c/WbcaGFAo for those with access.)
The old proposal only reuses a VG called "system". If such VG exists and is big enough, the required LVs will be created there.
The previous LVs will not be touched if there is enough free space. Otherwise, as many LVs as needed will be deleted (not necessarily all of them).
There is one special case. The proposal reuses (reformats) any LV named "root" (if it's big enough, I assume).
What the code in yast-storage-ng#pr111 does =========================================== The new proposal decides which VG to reuse (if any) based on the size, not on the name.
There is no reusing of LVs. The proposal simply deletes as many previous LVs as needed to make space for ours (it deletes none if there is enough free space already at the beginning). Pretty much like the old proposal does.
What's under discussion ======================= Steffen suggested that we should always just delete all LVs when reusing an existing VG. At least in the case when we don't fit into the original free space.
That would mean less logic to maintain, of course, but I wonder whether its a step backwards.
So I guess the question is - does it makes sense to be conservative when deleting LVs (trying to delete as few as possible) or should we go directly all the way through?
Cheers.
Well, interesting topic. When I testing, it is fine for me to delete everything and recreate from scratch. But If I as home user do fresh installation, I would like to keep LV with home or any "data" LV ( I often have data LV that is separated from home, as home contain also version specific configuration of packages, which I would like to kill for proper working of software, but I have separated data LV, which contains photos, videos and documents, which I after installation mount to target home. And there is third group which is corporate users, that probably are not so interested in home, as it is remote or having documents elsewhere, where I expect it is not problem to destroy all LVs. So from my POV(!) it make sense for openSUSE: - destroy only root and swap LV and try to reuse others for SLE: - destroy all Josef -- To unsubscribe, e-mail: yast-devel+unsubscribe@opensuse.org To contact the owner, e-mail: yast-devel+owner@opensuse.org
participants (4)
-
Ancor Gonzalez Sosa -
Arvin Schnell -
Josef Reidinger -
Steffen Winterfeldt