GNU GRUB（GRand Unified Bootloader簡稱“GRUB”）是一個來自GNU項目的多操作系統(tǒng)啟動程序。GRUB是多啟動規(guī)范的實現(xiàn)，它允許用戶可以在計算機內(nèi)同時擁有多個操作系統(tǒng)，并在計算機啟動時選擇希望運行的操作系統(tǒng)。GRUB可用于選擇操作系統(tǒng)分區(qū)上的不同內(nèi)核，也可用于向這些內(nèi)核傳遞啟動參數(shù)。

環(huán)境：Red Hat Enterprise Linux Server release 7.3

查看系統(tǒng)信息并重現(xiàn)故障

[root@localhost~]#lsb_release-aLSBVersion::core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarchDistributorID:RedHatEnterpriseServerDescription:RedHatEnterpriseLinuxServerrelease7.3(Maipo)Release:7.3Codename:Maipo[root@localhost~]#df-hFilesystemSizeUsedAvailUse%Mountedon/dev/mapper/rhel-root50G22G29G43%/devtmpfs1.9G01.9G0%/devtmpfs1.9G88K1.9G1%/dev/shmtmpfs1.9G9.0M1.9G1%/runtmpfs1.9G01.9G0%/sys/fs/cgroup/dev/sda11014M174M841M18%/boot/dev/sr03.6G3.6G0100%/media/cdrom/dev/mapper/rhel-home46G33M46G1%/hometmpfs378M8.0K378M1%/run/user/0[root@localhostgrub2]#grub2-install-Vgrub2-install(GRUB)2.02~beta2#用grub2-install--version也可以查看grub版本信息[root@localhost~]#ls/boot/grub2/device.mapfontsgrub.cfggrubenvi386-pclocalethemes[root@localhost~]#rm-rf/boot/grub2/grub.cfg[root@localhost~]#reboot

故障重現(xiàn)

手動引導系統(tǒng)

重裝grub

[root@localhost~]#ls/boot/grub2/device.mapfontsgrubenvi386-pclocalethemes[root@localhost~]#grub2-mkconfig>/boot/grub2/grub.cfgGeneratinggrubconfigurationfile...Foundlinuximage:/boot/vmlinuz-3.10.0-514.el7.x86_64Foundinitrdimage:/boot/initramfs-3.10.0-514.el7.x86_64.imgFoundlinuximage:/boot/vmlinuz-0-rescue-f0bcb62b11a44643824cde1c7f3833e4Foundinitrdimage:/boot/initramfs-0-rescue-f0bcb62b11a44643824cde1c7f3833e4.imgdone[root@localhost~]#ls/boot/grub2/device.mapfontsgrub.cfggrubenvi386-pclocalethemes[root@localhost~]#reboot#重啟驗證修復結果 重啟后能再次成功進入系統(tǒng)，說明修復成功！