#1804 PR merged: Do not start multipathd when not needed

Labels: enhancement, fixed / solved / done

schabrolles opened issue at 2018-05-09 17:07:

Relax-and-Recover (ReaR) Pull Request Template

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Pull Request Details:

  • Type: Enhancement

  • Impact: Low

  • Reference to related issue (URL):

  • How was this pull request tested?
    tested on POWER with sles11sp4

  • Brief description of the changes in this pull request:
    Having multipathd daemon started when not needed could bring some side-effect on some linux distribution (like sles11sp4).
    This could happen if you recover a system that previously used mutlipathed (with BOOT_ON_SAN=y)
    The purpose of the PR is to unload dm-multipath module (when user confirm that multipath is not needed) and only start multipath deamon if needed.

schabrolles commented at 2018-05-09 17:58:

I also print more useful info about the multpathed device discovered.
WWID and Size could really help the user to confirm the mapping proposed:

Setting up multipathing
Activating multipath
multipath activated
Starting multipath daemon
multipathd started
Listing multipath device found
mpathc (3600507680c82004cf8000000000008d5) dm-5 IBM,2145 size=10G
mpathb (3600507680c82004cf8000000000008d4) dm-3 IBM,2145 size=10G
mpatha (3600507680c82004cf8000000000000d8) dm-0 IBM,2145 size=50G
Comparing disks
Ambiguous possible target disks need manual configuration (more than one with same size found)
Switching to manual disk layout configuration
Using /dev/mapper/mpathc (same name and same size) for recreating /dev/mapper/mpathc
Using /dev/mapper/mpatha (same name and same size) for recreating /dev/mapper/mpatha
Current disk mapping table (source -> target):
    /dev/mapper/mpathc /dev/mapper/mpathc
    /dev/mapper/mpatha /dev/mapper/mpatha

[Export of Github issue for rear/rear.]