Linux动态链接库加载失败一例

安装pacemaker rpm包后，遇到启动失败的情况，原因和动态链接库的加载有关，以下是详细。

问题

编译生成pacemaker 1.1.15的rpm包，然后在其它机器上安装pacemaker rpm包后，启动失败。

[root@srdsdevapp73 ~]# service pacemaker start
Starting Pacemaker Cluster Manager                         [FAILED] 

环境

• CentOS 6.3 64bit

原因

通过strace发现pacemaker启动失败由于加载库libcoroipcc.so.4失败

[root@srdsdevapp73 ~]# strace -f service pacemaker start
...
[pid 19960] writev(2, [{"pacemakerd", 10}, {": ", 2}, {"error while loading shared libra"..., 36}, {": ", 2}, {"libcoroipcc.so.4", 16}, {": ", 2}, {"cannot open shared object file", 30}, {": 
... 

再用ldd检查pacemakerd，发现总共有3个库找不到

[root@srdsdevapp73 ~]# ldd /usr/sbin/pacemakerd
    linux-vdso.so.1 =>  (0x00007fffc4c9f000)
    libcrmcluster.so.4 => /usr/lib/libcrmcluster.so.4 (0x0000003cbac00000)
    libstonithd.so.2 => /usr/lib/libstonithd.so.2 (0x0000003cba400000)
    libcrmcommon.so.3 => /usr/lib/libcrmcommon.so.3 (0x0000003cb4c00000)
    libm.so.6 => /lib64/libm.so.6 (0x0000003cb3c00000)
    libcpg.so.4 => /usr/lib64/libcpg.so.4 (0x00007f3f72199000)
    libcfg.so.6 => /usr/lib64/libcfg.so.6 (0x00007f3f71f95000)
    libcmap.so.4 => /usr/lib64/libcmap.so.4 (0x00007f3f71d8f000)
    libquorum.so.5 => /usr/lib64/libquorum.so.5 (0x00007f3f71b8b000)
    libgnutls.so.26 => /usr/lib64/libgnutls.so.26 (0x0000003cb8800000)
    libcorosync_common.so.4 => /usr/lib64/libcorosync_common.so.4 (0x00007f3f71988000)
    libplumb.so.2 => /usr/lib64/libplumb.so.2 (0x00007f3f71754000)
    libpils.so.2 => /usr/lib64/libpils.so.2 (0x00007f3f7154b000)
    libqb.so.0 => /usr/lib64/libqb.so.0 (0x00007f3f712e6000)
    libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003cb2c00000)
    libbz2.so.1 => /lib64/libbz2.so.1 (0x0000003cb7000000)
    libxslt.so.1 => /usr/lib64/libxslt.so.1 (0x0000003cb4800000)
    libxml2.so.2 => /usr/lib64/libxml2.so.2 (0x0000003cb6000000)
    libc.so.6 => /lib64/libc.so.6 (0x0000003cb2400000)
    libuuid.so.1 => /lib64/libuuid.so.1 (0x0000003cb5000000)
    libpam.so.0 => /lib64/libpam.so.0 (0x0000003cb6c00000)
    librt.so.1 => /lib64/librt.so.1 (0x0000003cb3000000)
    libdl.so.2 => /lib64/libdl.so.2 (0x0000003cb2800000)
    libglib-2.0.so.0 => /lib64/libglib-2.0.so.0 (0x0000003cb3800000)
    libltdl.so.7 => /usr/lib64/libltdl.so.7 (0x0000003cb8400000)
    libcoroipcc.so.4 => not found
    libcfg.so.4 => not found
    libconfdb.so.4 => not found
    libtasn1.so.3 => /usr/lib64/libtasn1.so.3 (0x0000003cb7800000)
    libz.so.1 => /lib64/libz.so.1 (0x0000003cb3400000)
    libgcrypt.so.11 => /lib64/libgcrypt.so.11 (0x0000003cb7400000)
    /lib64/ld-linux-x86-64.so.2 (0x0000003cb2000000)
    libaudit.so.1 => /lib64/libaudit.so.1 (0x0000003cb6400000)
    libcrypt.so.1 => /lib64/libcrypt.so.1 (0x0000003cb5c00000)
    libgpg-error.so.0 => /lib64/libgpg-error.so.0 (0x0000003cb6800000)
    libfreebl3.so => /lib64/libfreebl3.so (0x0000003cb5800000) 

上面有一段"/usr/lib/libcrmcluster.so.4"比较奇怪，确认后发现文件不对，是以前安装的版本(不清楚当初怎么安装的了)。 正确的库位置应该是"/usr/lib64/libcrmcluster.so.4"。 将老版本的pacemaker删除后，一切正常

[root@srdsdevapp73 ~]# rm -f /usr/lib/libcrm*
[root@srdsdevapp73 ~]# rm -f /usr/lib/libstonithd.*
[root@srdsdevapp73 ~]# ldd /usr/sbin/pacemakerd
    linux-vdso.so.1 =>  (0x00007fff9a3ff000)
    libcrmcluster.so.4 => /usr/lib64/libcrmcluster.so.4 (0x00007f849a1fc000)
    libstonithd.so.2 => /usr/lib64/libstonithd.so.2 (0x00007f8499fea000)
    libcrmcommon.so.3 => /usr/lib64/libcrmcommon.so.3 (0x00007f8499d93000)
    libm.so.6 => /lib64/libm.so.6 (0x0000003cb3c00000)
    libcpg.so.4 => /usr/lib64/libcpg.so.4 (0x00007f8499b8c000)
    libcfg.so.6 => /usr/lib64/libcfg.so.6 (0x00007f8499988000)
    libcmap.so.4 => /usr/lib64/libcmap.so.4 (0x00007f8499782000)
    libquorum.so.5 => /usr/lib64/libquorum.so.5 (0x00007f849957e000)
    libgnutls.so.26 => /usr/lib64/libgnutls.so.26 (0x0000003cb8800000)
    libcorosync_common.so.4 => /usr/lib64/libcorosync_common.so.4 (0x00007f849937b000)
    libplumb.so.2 => /usr/lib64/libplumb.so.2 (0x00007f8499147000)
    libpils.so.2 => /usr/lib64/libpils.so.2 (0x00007f8498f3e000)
    libqb.so.0 => /usr/lib64/libqb.so.0 (0x00007f8498cd9000)
    libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003cb2c00000)
    libbz2.so.1 => /lib64/libbz2.so.1 (0x0000003cb7000000)
    libxslt.so.1 => /usr/lib64/libxslt.so.1 (0x0000003cb4800000)
    libxml2.so.2 => /usr/lib64/libxml2.so.2 (0x0000003cb6000000)
    libc.so.6 => /lib64/libc.so.6 (0x0000003cb2400000)
    libuuid.so.1 => /lib64/libuuid.so.1 (0x0000003cb5000000)
    libpam.so.0 => /lib64/libpam.so.0 (0x0000003cb6c00000)
    librt.so.1 => /lib64/librt.so.1 (0x0000003cb3000000)
    libdl.so.2 => /lib64/libdl.so.2 (0x0000003cb2800000)
    libglib-2.0.so.0 => /lib64/libglib-2.0.so.0 (0x0000003cb3800000)
    libltdl.so.7 => /usr/lib64/libltdl.so.7 (0x0000003cb8400000)
    libtasn1.so.3 => /usr/lib64/libtasn1.so.3 (0x0000003cb7800000)
    libz.so.1 => /lib64/libz.so.1 (0x0000003cb3400000)
    libgcrypt.so.11 => /lib64/libgcrypt.so.11 (0x0000003cb7400000)
    /lib64/ld-linux-x86-64.so.2 (0x0000003cb2000000)
    libaudit.so.1 => /lib64/libaudit.so.1 (0x0000003cb6400000)
    libcrypt.so.1 => /lib64/libcrypt.so.1 (0x0000003cb5c00000)
    libgpg-error.so.0 => /lib64/libgpg-error.so.0 (0x0000003cb6800000)
    libfreebl3.so => /lib64/libfreebl3.so (0x0000003cb5800000)
[root@srdsdevapp73 ~]# service pacemaker start
Starting Pacemaker Cluster Manager                         [  OK  ] 

总结

Linux下查找动态链接库的默认路径(未在/etc/ld.so.conf中设置，动态链接库加载时会优先查找/etc/ld.so.cache中库)的顺序如下，如果有同名的库文件挡在前面，可能导致动态链接库加载失败。

1. /lib
2. /usr/lib
3. /lib64
4. /usr/lib64