[LU-19993] FLR-EC-IWM: lfs setstripe --immediate support

• Type: Technical task
• Resolution: Unresolved
• Priority: Medium
• Labels: FLR-EC FLR-EC-IWM
• Severity: 3
• Assignee: WC Triage
• Reporter: Patrick Farrell

Description

Add --immediate option to lfs setstripe and lfs mirror create for creating immediate mirror layouts.

This follows the EC pattern (Gerrit 61965): EC added --ec k+m notation, IWM just needs a boolean flag on the mirror components.

lfs setstripe (lustre/utils/lfs.c):

• Add --immediate option to lfs setstripe and lfs mirror create
• When specified, set LCME_FL_IMMEDIATE on all components of the mirrors being created
• Require >= 2 mirrors when --immediate is used

Semantics:

• lfs setstripe -N2 --immediate: flag on all mirrors
• lfs mirror create --immediate: same, error if < 2
• Directory defaults: template must have >= 2 mirrors with IMMEDIATE

Tests (lustre/tests/sanity-flr.sh or new test file):

• Basic layout creation with --immediate
• Verify flag persists through getstripe
• Verify rejection when feature is disabled
• Verify directory default inheritance
• Verify error when --immediate with only one mirror

Reference EC patches:

• Gerrit 61965: LU-12187 lfs: add EC setstripe support with k+m notation

Issue Links

• is blocked by: LU-19991 FLR-EC-IWM: llapi layout support and kernel layout passthrough for immediate mirrors
• is blocking: LU-19995 FLR-EC-IWM: block LCME_FL_IMMEDIATE in --comp-set