nagios_multipath_paths_per_volume ought to support "N+" paths

[sudeephb]

The files/check_iscsi_metric.py script, together with the nagios_multipath_paths_per_volume charm option, allows for checking the number of multipath paths per volume.

However, in at least one customer's environment, they have 2 different flash arrays and they return different numbers of paths - one gives 4 paths per volume, while the other gives 8 paths per volume. Since all the computes in use by this customer may have volumes from either array (i.e. either 4 or 8 paths in a fully healthy case), this check doesn't seem like it quite works for the cloud in question.

I think we may want to consider either changing this option to work like a threshold rather than an exact match (e.g. 4+ paths is OK but <4 triggers an alert), or at least have an option to switch to such behavior, as an exact match on 4 paths simply won't work in this case as long as one of the customer's flash arrays return 8 paths per volume.

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Imported from Launchpad using lp2gh.

• date created: 2023-02-15T22:12:57Z

• owner: vultaire

• assignee: None

• the launchpad url

[sudeephb]

(by aieri)
In the wider context of switching to metric-based alerting (and COS integration), this request may be better satisfied by tracking the number of paths per volume and alerting on a decrease, whichever the max may be