5.7. Multipath Command Output
When you create, modify, or list a multipath device, you get a display of the current device setup. The format is as follows.
对于每个多路径设备：
action_if_any: alias (wwid_if_different_from_alias) dm_device_name_if_known vendor,product size=size features='features' hwhandler='hardware_handler' wp=write_permission_if_known
对与每个路径组群：
-+- policy='scheduling_policy' prio=prio_if_known status=path_group_status_if_known
对于每个路径：
`- host:channel:id:lun devnode major:minor dm_status_if_known path_status online_status
例如，多路径命令的输出可能是如下形式：
3600d0230000000000e13955cc3757800 dm-1 WINSYS,SF2372 size=269G features='0' hwhandler='0' wp=rw |-+- policy='round-robin 0' prio=1 status=active | `- 6:0:0:0 sdb 8:16 active ready running `-+- policy='round-robin 0' prio=1 status=enabled `- 7:0:0:0 sdf 8:80 active ready running
If the path is up and ready for I/O, the status of the path is
ready or ghost. If the path is down, the status is faulty or shaky. The path status is updated periodically by the multipathd daemon based on the polling interval defined in the /etc/multipath.conf file.
The dm status is similar to the path status, but from the kernel's point of view. The dm status has two states:
failed, which is analogous to faulty, and active which covers all other path states. Occasionally, the path state and the dm state of a device will temporarily not agree.
The possible values for
online_status are running and offline. A status of offline means that this SCSI device has been disabled.
注意
When a multipath device is being created or modified, the path group status, the dm device name, the write permissions, and the dm status are not known. Also, the features are not always correct.
