centos7自带的glibc满足要求,不需要升级.
centos6需要升级glibc,但编译安装glibc极易出错导致系统命令不能使用,因此使用一下rpm包的方式升级
有网情况下,可以在线下载rpm包的方式
无网情况下,可以上传打包好的rpm包

方式1 在线下载方式
mkdir /data/tools/glibc -p && cd /data/tools/glibc
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-utils-2.17-55.el6.x86_64.rpm &
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-static-2.17-55.el6.x86_64.rpm &
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-2.17-55.el6.x86_64.rpm &
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-common-2.17-55.el6.x86_64.rpm &
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-devel-2.17-55.el6.x86_64.rpm &
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-headers-2.17-55.el6.x86_64.rpm &
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/nscd-2.17-55.el6.x86_64.rpm &

2)安装rpm包

rpm -Uvh *-2.17-55.el6.x86_64.rpm --force --nodeps
ldd --version