客户的服务器在过年时，被火烧掉了，客户找数据恢复公司恢复出来了数据，但是应用还是无法访问，最后到了apache这里,apache2 无法启动, 说libsasl2.so.2 找不到，apache 无法启动.

解决方法: 
# whereis httpd 
找出你的httpd 的安装绝对路径. 如 /usr/sbin/httpd

#ldd /usr/sbin/httpd 
libpcre.so.0 => /lib/libpcre.so.0 (0xf6f8a000) 
libpcreposix.so.0 => /usr/lib/libpcreposix.so.0 (0xf6f86000) 
libaprutil-0.so.0 => /usr/lib/libaprutil-0.so.0 (0xf6f72000) 
libldap-2.2.so.7 => /usr/lib/libldap-2.2.so.7 (0xf6f41000) 
liblber-2.2.so.7 => /usr/lib/liblber-2.2.so.7 (0xf6f35000) 
libdb-4.2.so => /lib/tls/i686/libdb-4.2.so (0xf6e67000) 
libexpat.so.0 => /usr/lib/libexpat.so.0 (0xf6e48000) 
libapr-0.so.0 => /usr/lib/libapr-0.so.0 (0xf6e25000) 
librt.so.1 => /lib/tls/librt.so.1 (0xf6e11000) 
libm.so.6 => /lib/tls/libm.so.6 (0xf6dee000) 
libcrypt.so.1 => /lib/libcrypt.so.1 (0xf6dc0000) 
libpthread.so.0 => /lib/tls/libpthread.so.0 (0xf6dae000) 
libdl.so.2 => /lib/libdl.so.2 (0xf6daa000) 
libc.so.6 => /lib/tls/libc.so.6 (0xf6c82000) 
libresolv.so.2 => /lib/libresolv.so.2 (0xf6c6e000) 
libsasl2.so.2 => not found 
libssl.so.4 => /lib/libssl.so.4 (0xf6c26000) 
libcrypto.so.4 => /lib/libcrypto.so.4 (0xf6b3e000) 
/lib/ld-linux.so.2 (0xf6fab000) 
libgssapi_krb5.so.2 => /usr/lib/libgssapi_krb5.so.2 (0xf6b29000) 
libkrb5.so.3 => /usr/lib/libkrb5.so.3 (0xf6ac4000) 
libcom_err.so.2 => /lib/libcom_err.so.2 (0xf6ac1000) 
libk5crypto.so.3 => /usr/lib/libk5crypto.so.3 (0xf6aa0000) 
libz.so.1 => /usr/lib/libz.so.1 (0xf6a90000)

#whereis libsasl2.so.2 
/usr/local/lib/libsasl2.so.2

/usr/local/lib/libsasl2.so.2.0.21

ls -l /usr/local/lib/libsasl2.so.2 
发现 /usr/local/lib/libsasl2.so.2==>/usr/local/lib/libsasl2.so.2.0.21

所以 ln -s /usr/local/lib/libsasl2.so.2.0.21 /lib/libsasl2.so.2

然后再检查一下:#ldd /usr/sbin/httpd

libpcre.so.0 => /lib/libpcre.so.0 (0xf6f8a000) 
libpcreposix.so.0 => /usr/lib/libpcreposix.so.0 (0xf6f86000) 
libaprutil-0.so.0 => /usr/lib/libaprutil-0.so.0 (0xf6f72000) 
libldap-2.2.so.7 => /usr/lib/libldap-2.2.so.7 (0xf6f41000) 
liblber-2.2.so.7 => /usr/lib/liblber-2.2.so.7 (0xf6f35000) 
libdb-4.2.so => /lib/tls/i686/libdb-4.2.so (0xf6e67000) 
libexpat.so.0 => /usr/lib/libexpat.so.0 (0xf6e48000) 
libapr-0.so.0 => /usr/lib/libapr-0.so.0 (0xf6e25000) 
librt.so.1 => /lib/tls/librt.so.1 (0xf6e11000) 
libm.so.6 => /lib/tls/libm.so.6 (0xf6dee000) 
libcrypt.so.1 => /lib/libcrypt.so.1 (0xf6dc0000) 
libpthread.so.0 => /lib/tls/libpthread.so.0 (0xf6dae000) 
libdl.so.2 => /lib/libdl.so.2 (0xf6daa000) 
libc.so.6 => /lib/tls/libc.so.6 (0xf6c82000) 
libresolv.so.2 => /lib/libresolv.so.2 (0xf6c6e000) 
libsasl2.so.2 => /lib/libsasl2.so.2 (0xf6c5a000) 
libssl.so.4 => /lib/libssl.so.4 (0xf6c26000) 
libcrypto.so.4 => /lib/libcrypto.so.4 (0xf6b3e000) 
/lib/ld-linux.so.2 (0xf6fab000) 
libgssapi_krb5.so.2 => /usr/lib/libgssapi_krb5.so.2 (0xf6b29000)

libkrb5.so.3 => /usr/lib/libkrb5.so.3 (0xf6ac4000) 
libcom_err.so.2 => /lib/libcom_err.so.2 (0xf6ac1000) 
libk5crypto.so.3 => /usr/lib/libk5crypto.so.3 (0xf6aa0000) 
libz.so.1 => /usr/lib/libz.so.1 (0xf6a90000)

重新启动 httpd , OK 了.

本文转自南非蚂蚁51CTO博客，原文链接：http://blog.51cto.com/ixdba/526104 ，如需转载请自行联系原作者