[LU-5134] Add option to lctl set_param for setting parameters in parallel

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Labels: patch

Epic/Theme

Performance

• Assignee: Ryan Haasken
• Reporter: Ryan Haasken

Description

lctl set_param should have an option to set a parameter across multiple matched files in parallel. For instance, if you execute this lctl set_param command:

lctl set_param [parallel-option] ldlm.namespaces.*osc*.lru_size=clear

it should write "clear" to the files matching the given parameter pattern in parallel.

This enhancement is required to speed up clearing of Lustre caches. When there are many OSTs, executing

lctl set_param ldlm.namespaces.*.lru_size=clear

takes a long time, and there is no reason that the lru_size files can't be written to in parallel. Then the work can be done on each OST in parallel.

For example, with 16 OSTs, it takes 5.4 seconds to clear caches across all namespaces. This could be sped up by parallelizing the write to lru_size across the namespaces.

If this enhancement is added, then LU-3970 can also be resolved.

Issue Links

• is related to: LU-3970 Add procfs interface for clearing lustre caches in parallel