[LU-7131] new options for tunefs.lustre

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.10.0
• Affects Version/s: Lustre 2.8.0
• Labels: patch
• Severity: 3
• Assignee: Emoly Liu
• Reporter: parinay v kondekar (Inactive)

Description

Sometimes it requires to modify lustre parameters in a batch job, for example High Speed Network (HSN) (re)configuration requires to change MGS and failover NIDs, and AD support adds/replaces mdt.identity_upcall option.
Currently the only option is to read all options already applied to a target, modify this list externally, then write them back with --erase-params flag. It's fine to do that for a single target update, but mass updates require non-trivial workarounds.
I propose to add the following option to tunefs.lustre:

--replace-param - it will replace or add parameters given in the command line, keeping the rest of them unchanged
The other useful option may be "--erase-param", with removes parameter that follows from the target.

--param ... - adds a parameter, possibly leaving multiple copies (may have "--add-param" alias)
--replace-param ... sets parameter, removing all previous values
--erase-param ... - removes parameter, keeping the rest

--replace-param p=v1 --param p=v2 should lead to two values saved.