Thanks for the patch! comments inline: On Wed, 12 Mar 2025 16:15:02 +0100 Friedrich Weber <f.we...@proxmox.com> wrote:
> Automatic memory allocation (ballooning) is implemented in pvestatd, which > assigns memory to or reclaims memory from eligible VMs in order to reach a > certain target memory usage on the host. The target is currently hardcoded at > 80%. Users have reported [1] that this target is unnecessarily low on hosts > with large amounts of RAM. > > This patch series makes the ballooning target configurable. For this, it adds > a > new node config option `ballooning-target`. pvestatd then reads the target > from > that option. > > Some potential discussion points: > > - Is it OK to have this as a node option? I imagine some users may want to set > different targets on different nodes. But other users may want to set one > target for the whole cluster. Should we have a `ballooning-target` > datacenter > option that can be overridden by a `ballooning-target` node option? This > might > be overkill for such a simple option, though. my initial thought would put this on the Datacenter-level (expecting most nodes to be similarly specced - and thus have similar settings). OTOH your approach gives the user more flexibility (if at the expense of having to set that (via config-management or manually) for all nodes). I think we could keep it on the node-level, and if there is demand for this follow it up as you suggested: node-setting > datacenter-setting > default(80%) > > - Instead of a `ballooning-target` option, should we go for some general > `ballooning-settings` with a property string like `target=80`, in case we > want > to make other values (such as `$maxchange`, which is currently hardcoded at > 100 > MiB) configurable in the future too? we could cross that bridge when we get to it/when someone requests this change (via versioned postinst renaming)? - at least I don't see the gain - especially when it's in node.cfg. and even if we have a datacenter.cfg-wide setting in a mixed-version cluster while upgrading the config-parser would complain about an unknown entry in a property-string as much as about an unknown setting IIRC? > > - In a mixed-version cluster where node 1 has this patch series and node 2 > doesn't yet, any attempt to change node 2's ballooning target from node 1's > GUI > will error out with `ballooning-target: property is not defined in schema`. > This is not very nice, but not terrible either, as the error message is > relatively descriptive. Still, is there an easy way to avoid this (checking > client-side whether the option exists?) I think the error-message is acceptable here (and nodes in a cluster should run the same versions sooner rather than later anyways). gave it a quick spin (by installing on my host, setting the target to 10%, adding a `balloon` setting for a VM of mine and running `pvestatd start --debug 1`, watching it inflate the balloon and the setting the target to 99%, watching it deflate it again). For me this can be applied as-is: Tested-by: Stoiko Ivanov <s.iva...@proxmox.com> Reviewed-by: Stoiko Ivanov <s.iva...@proxmox.com> > > [1] https://bugzilla.proxmox.com/show_bug.cgi?id=2413 > > manager: > > Friedrich Weber (3): > node: options: add config option for ballooning target > fix #2413: pvestatd: read ballooning RAM usage target from node config > ui: node options: allow editing the ballooning RAM usage target > > PVE/NodeConfig.pm | 8 ++++++++ > PVE/Service/pvestatd.pm | 10 +++++++--- > www/manager6/node/NodeOptionsView.js | 18 ++++++++++++++++++ > 3 files changed, 33 insertions(+), 3 deletions(-) > > > docs: > > Friedrich Weber (1): > pvenode: document ballooning-target node option > > pvenode.adoc | 13 +++++++++++++ > qm.adoc | 13 ++++++++----- > 2 files changed, 21 insertions(+), 5 deletions(-) > > > Summary over all repositories: > 5 files changed, 54 insertions(+), 8 deletions(-) > _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
