[LU-4160] Default HSM paramters need to be updated

• Status: Open
• Project: Lustre
• Affects Version/s: Lustre 2.5.0, Lustre 2.6.0, Lustre 2.5.1
• Type: Improvement
• Priority: Minor
• Reporter: James Nunez (Inactive)
• Assignee: WC Triage
• Resolution: Unresolved
• Labels: HSM

Environment

OpenSFS cluster with RHEL6 with combined MGS/MDS, single OSS with two OSTs, four Lustre 2.5 (Build #2) clients; one HSM Agent + client, one with robinhood/db running and two Lustre clients.

Description

Currently, the default HSM default parameters, when HSM is enabled, are:

# lctl get_param mdt.scratch-MDT0000.hsm_control
mdt.scratch-MDT0000.hsm_control=enabled
# lctl get_param mdt.scratch-MDT0000.hsm.actions
# lctl get_param mdt.scratch-MDT0000.hsm.agents
mdt.scratch-MDT0000.hsm.agents=
uuid=181c8885-24a1-2d51-0b7e-3b986fff7a93 archive_id=1 requests=[current:0 ok:6917 errors:0]
# lctl get_param mdt.scratch-MDT0000.hsm.default_archive_id
mdt.scratch-MDT0000.hsm.default_archive_id=3
# lctl get_param mdt.scratch-MDT0000.hsm.grace_delay
mdt.scratch-MDT0000.hsm.grace_delay=60
# lctl get_param mdt.scratch-MDT0000.hsm.loop_period
mdt.scratch-MDT0000.hsm.loop_period=10
# lctl get_param mdt.scratch-MDT0000.hsm.max_requests
mdt.scratch-MDT0000.hsm.max_requests=3
# lctl get_param mdt.scratch-MDT0000.hsm.policy
mdt.scratch-MDT0000.hsm.policy=NonBlockingRestore [NoRetryAction]
# lctl get_param mdt.scratch-MDT0000.hsm.active_requests
# lctl get_param mdt.scratch-MDT0000.hsm.active_request_timeout
mdt.scratch-MDT0000.hsm.active_request_timeout=3600

The hsm.max_requests value of 3 differs from what is documented in the HSM test plan; "10 x Agent count". Thus, the default value of hsm.max_requests should be changed.

From the documentation, max_requests is a per coordinator value. If there are two coordinators (MDTs), each agents will never have to handle more than 2 x max_requests requests.