Will restarting multipath affect production?

环境

• Red Hat Enterprise Linux 5, 6, 7

问题

• What is the production impact of restarting multipath?

决议

• Running multipath with no parameters, will not cause any existing paths to fail or interrupt any current transfers.

Raw

# multipath

• If any changes have been made to /etc/multipath.conf then restarting multipath will affect production.
  Its recommended to run the command 'stat /etc/multipath.conf' to check on any recent modifications.

If no changes have been made, than restarting multipath will not affect production.

Raw

# service multipath restart

You can verify this details with the following command to check on the connections.

Raw

# multipath -ll

The reason that production won't be affected is that existing multipaths have in-use reference counts in the kernel dm table.