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| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-08-22 06:50:55 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-09-22 21:07:27 +0200 |
| commit | fe8fc5ae5c808e037fa4746cbfeb3c07ffe0af81 (patch) | |
| tree | 973ce75621cb47f79167bde4e48bdc357ed58bde /docs | |
| parent | b855f8d175a0a26c9798cbc5962bb8c0d9538231 (diff) | |
| download | qemu-fe8fc5ae5c808e037fa4746cbfeb3c07ffe0af81.tar.gz | |
scsi: add multipath support to qemu-pr-helper
Proper support of persistent reservation for multipath devices requires
communication with the multipath daemon, so that the reservation is
registered and applied when a path comes up. The device mapper
utilities provide a library to do so; this patch makes qemu-pr-helper.c
detect multipath devices and, when one is found, delegate the operation
to libmpathpersist.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/pr-manager.rst | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/docs/pr-manager.rst b/docs/pr-manager.rst index 7107e59fb8..9b1de198b1 100644 --- a/docs/pr-manager.rst +++ b/docs/pr-manager.rst @@ -60,6 +60,7 @@ system service and supports the following option: -d, --daemon run in the background -q, --quiet decrease verbosity +-v, --verbose increase verbosity -f, --pidfile=path PID file when running as a daemon -k, --socket=path path to the socket -T, --trace=trace-opts tracing options @@ -82,3 +83,29 @@ its operation. To do this, add the following options: -u, --user=user user to drop privileges to -g, --group=group group to drop privileges to + +--------------------------------------------- +Multipath devices and persistent reservations +--------------------------------------------- + +Proper support of persistent reservation for multipath devices requires +communication with the multipath daemon, so that the reservation is +registered and applied when a path is newly discovered or becomes online +again. :command:`qemu-pr-helper` can do this if the ``libmpathpersist`` +library was available on the system at build time. + +As of August 2017, a reservation key must be specified in ``multipath.conf`` +for ``multipathd`` to check for persistent reservation for newly +discovered paths or reinstated paths. The attribute can be added +to the ``defaults`` section or the ``multipaths`` section; for example:: + + multipaths { + multipath { + wwid XXXXXXXXXXXXXXXX + alias yellow + reservation_key 0x123abc + } + } + +Linking :program:`qemu-pr-helper` to ``libmpathpersist`` does not impede +its usage on regular SCSI devices. |