红帽全球峰会5.5. 大量 LUN 造成的问题
当在某个节点中添加大量 LUN 时，使用多路径设备可明显延长
udev 设备过滤器为其生成设备节点所用的时间。如果您遇到过这个问题，您可在 /etc/udev/rules.d/40-multipath.rules 文件中删除以下行解决这个问题：
KERNEL!="dm-[0-9]*", ACTION=="add", PROGRAM=="/bin/bash -c '/sbin/lsmod | /bin/grep ^dm_multipath'", RUN+="/sbin/multipath -v0 %M:%m"
KERNEL!="dm-[0-9]*", ACTION=="add", PROGRAM=="/bin/bash -c '/sbin/lsmod | /bin/grep ^dm_multipath'", RUN+="/sbin/multipath -v0 %M:%m"
这行会在每次向该节点中添加块设备时让
udev 设备管理器运行 multipath。虽然删除了这一行，multipathd 守护进程仍将自动生成多路径设备，在引导过程中仍将为带多路径根文件系统的节点调用 multipath。唯一的改变就是没有运行 multipathd 守护进程不再自动生成多路径设备，对大多数多路径用户来说应该不是个问题。
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