Booting Rescue Mode


To start your system in rescue mode, boot from a Red Hat Linux boot disk or the Red Hat Linux CD-ROM #1, and enter the following command at the installation boot prompt:

boot: linux rescue

You can get to the installation boot prompt in one of these ways:

  • By booting your system from an installation boot diskette made from the boot.img image. This method requires that the Red Hat Linux CD-ROM #1 be inserted as the rescue image or that the rescue image be on the hard drive as an ISO image. To create an installation boot diskette, insert a blank floppy disk and use the images/boot.img file on the Red Hat Linux CD-ROM #1 with the command dd if=boot.img of=/dev/fd0.

  • By booting your system from the Red Hat Linux CD-ROM #1.

  • By booting from a network disk made from the bootnet.img or PCMCIA boot disk made from pcmcia.img. You can do this only if your network connection is working. You will need to identify the network host and transfer type. For an explanation of how to specify this information, refer to the Official Red Hat Linux User’s Guide (Red Hat Press/Wiley, 2003).

After booting off a boot disk or Red Hat Linux CD-ROM #1 and providing a valid rescue image, you will see the following message:

The rescue environment will now attempt to find your Red Hat Linux  installation and mount it under the directory /mnt/sysimage. You can  then make any changes required to your system. If you want to proceed  with this step choose 'Continue'. You can also choose to mount your  filesystem read-only instead of read-write by choosing 'Read-only'.

If for some reason this process fails, you can choose “Skip.” This step will be skipped and you will go directly to a command shell.

If you select Continue, the rescue diskette will attempt to mount your file system under the directory /mnt/sysimage. If the rescue process fails to mount a partition, it will notify you. If you select Read-Only, the rescue process will attempt to mount your file system under the directory /mnt/sysimage, but in read-only mode. If you select Skip, your file system will not be mounted. Choose Skip if you think your file system is corrupted.

Once you have your system in rescue mode, a prompt appears on VC (virtual console) 1 and VC 2 (use the Ctrl-Alt-F1 key combination to access VC 1 and Ctrl-Alt-F2 to access VC 2):

sh-2.05a#

If you selected Continue to mount your partitions automatically and they were mounted successfully, you are in single-user mode. To mount a Linux partition manually inside rescue mode, create a directory such as /foo and type the following command:

mount -t ext3 /dev/hda5 /foo

In the above command, /foo is a directory that you have created and /dev/hda5 is the partition you want to mount. If the partition is of type ext2, replace ext3 with ext2. If you do not know the names of your partitions, use the following command to list them:

fdisk -l

If your file system is mounted and you want to make your system the root partition, use the command chroot /mnt/sysimage. This is useful if you need to run commands such as rpm that require your root partition to be mounted as /. To exit the chroot environment, type exit, and you will return to the prompt.

From the bash# prompt, you can run many useful commands including:

anaconda          gzip        mkfs.ext2       probe badblocks         head        mknod           ps bash              hwclock     mkraid          python2.2 cat               ifconfig    mkswap          raidstart chattr            init        mlabel          raidstop chmod             insmod      mmd             rcp chroot            less        mmount          rlogin clock             ln          mmove           rm collage           loader      modprobe        rmmod cp                ls          mount           route cpio              lsattr      mpartition      rpm dd                lsmod       mrd             rsh ddcprobe          mattrib     mread           sed depmode           mbadblocks  mren            sh df                mcd         mshowfat        sync e2fsck            mcopy       mt              tac fdisk             mdel        mtools          tail fsck              mdeltree    mtype           tar fsck.ext2         mdir        mv              touch fsck.ext3         mdu         mzip            traceroute ftp               mformat     open            umount gnome-pty-helper  minfo       parted          uncpio grep              mkdir       pico            uniq gunzip            mke2fs      ping            zcat




Official Red Hat Linux Administrator's Guide
Official Red Hat Linux Administrators Guide
ISBN: 0764516957
EAN: 2147483647
Year: 2002
Pages: 278
Authors: Red Hat Inc

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