Apply tunings using lctl command

[degremont]

Use lctl set_param to apply tunings becomes more and more important. Doing this manually requires that Shine runs hundreds of commands in parallel which can create some issues. And latest Lustre version (2.9+) is moving away from /proc and is using /sys. lctl makes this move transparent, taking care of writing in the correct place.

First things could be to support a new syntax in tuning.conf, along the current one. osc.*.max_dirty_mb=1024 NODELIST

If this kind of lines is detected, Shine will run lctl instead of doing it with echo. This offers a smooth way to migrate.

It could be nice if the new syntax is compatible with either ModelFile or YAML syntax, to avoid maintaining another parser.

[tl-cea]

By doing this change, it would be nice to actually support any custom lctl command.

In particular, when many lnet routes have to be defined, they can't be passed as module arguments (limited to 1024 chars), so they have to be specified after loading lustre modules using lctl add_route.

Do you think this can be part of the same change, or should I open a specific ticket for that change request?

[degremont]

LNET config will be handled by a lnetctl import call. All LNET config will be moved into a YAML config file. See http://doc.lustre.org/lustre_manual.xhtml#idm140684903131360

A separate ticket will track support for this call.