Solaris下修改网卡MTU

steelesu

这几天一直在装Sun Cluster，两台SuFire V890，双机通过PCI扩展的千兆网卡连接到一个普通交换机互联，安装过程中碰到下面的错误，
Sep 20 20:27:50 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being cleaned up
Sep 20 20:27:50 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being drained
Sep 20 20:27:50 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being constructed
Sep 20 20:27:50 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being initiated
Sep 20 20:27:50 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 online
Sep 20 20:29:59 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce0 - clusterhost2:ce0 being cleaned up
Sep 20 20:29:59 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce0 - clusterhost2:ce0 being drained
Sep 20 20:29:59 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce0 - clusterhost2:ce0 being constructed
Sep 20 20:29:59 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce0 - clusterhost2:ce0 being initiated
Sep 20 20:29:59 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce0 - clusterhost2:ce0 online
Sep 20 20:32:09 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being cleaned up
Sep 20 20:32:09 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being drained
Sep 20 20:32:09 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being constructed
Sep 20 20:32:09 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 being initiated
Sep 20 20:32:09 clusterhost1 cl_runtime: NOTICE: clcomm: Path clusterhost1:ce1 - clusterhost2:ce1 online
看上去是双机互联的网卡不停重启，百思不得其解，不经意间发现这两个千兆口的MTU都是9194，ce1: flags=1008843 mtu 9194 index 4
    inet 172.16.1.1 netmask ffffff80 broadcast 172.16.1.127
    ether 0:3:ba:d9:f0:7f
ce0: flags=1008843 mtu 9194 index 5
    inet 172.16.0.129 netmask ffffff80 broadcast 172.16.0.255
    ether 0:3:ba:d9:f0:7e
由于我是通过一个普通的交换机把这些千兆口连起来的，MTU最大只能支持到1500，问题应该就出在这里，想办法将这两块网卡的MTU降到1500，命令也很简单，
ifconfig ce0 mtu 1500
ifconfig ce1 mtu 1500
改完之后，原来的错误提示消失，sun cluster的安装继续进行。特别说一句，网上有朋友想用上面的命令把一块普通网卡mtu修改成大于1500失败，应该是网卡驱动本身不支持mtu大于1500。


本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u1/48940/showart_396909.html