客戶的服務器在過年時，被火燒掉了，客戶找數據恢復公司恢復出來了數據，但是應用還是無法訪問，最好到了apache這裡,apache2 無法啟動, 說libsasl2.so.2 找不到，apache 無法啟動.
解決方法:
# whereis httpd
找出你的httpd 的安裝絕對路徑. 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
發現 /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
然後再檢查一下:#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)
重新啟動 httpd , OK 了.