运行yum后出现yum remove crontabs ： -bash: /usr/bin/yum: No such file or directory
这是yum remove crontabs的输出：
[root@vs270 opt]# yum remove crontabs Loaded plugins: fastestmirror Setting up Remove Process Resolving Dependencies --> Running transaction check ---> Package crontabs.noarch 0:1.10-8 set to be erased --> Processing Dependency: crontabs for package: rpm --> Running transaction check ---> Package rpm.x86_64 0:4.4.2.3-20.el5_5.1 set to be erased --> Processing Dependency: rpm = 4.4.2.3-20.el5_5.1 for package: rpm-python --> Processing Dependency: rpm = 4.4.2.3-20.el5_5.1 for package: rpm-libs --> Processing Dependency: rpm >= 3.0.5 for package: apt --> Processing Dependency: rpm >= 4.4.2 for package: yum --> Running transaction check ---> Package apt.x86_64 0:0.5.15lorg3.94a-5.el5.rf set to be erased ---> Package rpm-libs.x86_64 0:4.4.2.3-20.el5_5.1 set to be erased ---> Package rpm-python.x86_64 0:4.4.2.3-20.el5_5.1 set to be erased ---> Package yum.noarch 0:3.2.22-26.el5.centos set to be erased --> Processing Dependency: yum >= 3.0 for package: yum-fastestmirror --> Running transaction check ---> Package yum-fastestmirror.noarch 0:1.1.16-14.el5.centos.1 set to be erased --> Processing Dependency: /bin/rpm for package: policycoreutils --> Restarting Dependency Resolution with new changes. --> Running transaction check ---> Package policycoreutils.x86_64 0:1.33.12-14.8.el5 set to be erased --> Processing Dependency: policycoreutils >= 1.33.12-14.5 for package: selinux-policy --> Processing Dependency: policycoreutils for package: setools --> Running transaction check ---> Package selinux-policy.noarch 0:2.4.6-279.el5_5.2 set to be erased ---> Package setools.x86_64 0:3.0-3.el5 set to be erased --> Finished Dependency Resolution Dependencies Resolved ==================================================================================================================================================================================================== Package Arch Version Repository Size ==================================================================================================================================================================================================== Removing: crontabs noarch 1.10-8 installed 1.0 k Removing for dependencies: apt x86_64 0.5.15lorg3.94a-5.el5.rf installed 8.5 M policycoreutils x86_64 1.33.12-14.8.el5 installed 2.1 M rpm x86_64 4.4.2.3-20.el5_5.1 installed 3.6 M rpm-libs x86_64 4.4.2.3-20.el5_5.1 installed 2.0 M rpm-python x86_64 4.4.2.3-20.el5_5.1 installed 131 k selinux-policy noarch 2.4.6-279.el5_5.2 installed 7.5 M setools x86_64 3.0-3.el5 installed 3.3 M yum noarch 3.2.22-26.el5.centos installed 3.2 M yum-fastestmirror noarch 1.1.16-14.el5.centos.1 installed 47 k Transaction Summary ==================================================================================================================================================================================================== Remove 10 Package(s) Reinstall 0 Package(s) Downgrade 0 Package(s) Is this ok [y/N]: y Downloading Packages: Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Erasing : crontabs 1/10 Erasing : rpm-python 2/10 Erasing : yum 3/10 warning: /etc/yum.conf saved as /etc/yum.conf.rpmsave Erasing : apt 4/10 warning: /etc/apt/sources.list.d/os.list saved as /etc/apt/sources.list.d/os.list.rpmsave Erasing : rpm 5/10 Erasing : selinux-policy 6/10 Erasing : policycoreutils 7/10 Erasing : rpm-libs 8/10 Erasing : yum-fastestmirror 9/10 Erasing : setools 10/10 Removed: crontabs.noarch 0:1.10-8 Dependency Removed: apt.x86_64 0:0.5.15lorg3.94a-5.el5.rf policycoreutils.x86_64 0:1.33.12-14.8.el5 rpm.x86_64 0:4.4.2.3-20.el5_5.1 rpm-libs.x86_64 0:4.4.2.3-20.el5_5.1 rpm-python.x86_64 0:4.4.2.3-20.el5_5.1 selinux-policy.noarch 0:2.4.6-279.el5_5.2 setools.x86_64 0:3.0-3.el5 yum.noarch 0:3.2.22-26.el5.centos yum-fastestmirror.noarch 0:1.1.16-14.el5.centos.1 Complete!
任何想法如何重新安装YUM没有YUM本身？ 感谢：D
可以通过从RPM-rpm（uhuh）软件包中解压缩文件来安装RPM。 这会让你再次去，你也可以安装yum。 首先创build您要用于从RPM存档中解压文件的目录并下载RPM软件包。
mkdir /tmp/becarefulnexttime cd /tmp/becarefulnexttime wget http://ftp.tudelft.nl/centos.org/5/os/x86_64/CentOS/rpm-4.4.2.3-22.el5.x86_64.rpm
确保你下载了与你的CentOS版本/体系结构相对应的RPM版本，但看看你的yum输出，我认为这是。
现在，从RPM档案文件中提取文件，并将重要文件复制到您的CentOS安装根目录。
rpm2cpio rpm-4.4.2.3-22.el5.x86_64.rpm | cpio -dim find . -type d -exec chmod 755 {} \; tar cf - ./usr ./etc | (cd /; tar xvf -)
你现在应该有一个工作的rpm命令，重buildRPM数据库并正确安装RPM：
rpm --rebuilddb rpm -i rpm-4.4.2.3-22.el5.x86_64.rpm
您可能需要一些额外的依赖关系，但是现在应该可以再次安装yum了
rpm -i http://ftp.tudelft.nl/centos.org/5/os/x86_64/CentOS/yum-3.2.22-33.el5.centos.noarch.rpm
你可以手动重新编译rpm包，安装，然后安装yum，但除非这是一个关键任务盒，否则备份configuration和重新安装可能会更快。
尝试从tar球源安装。