You are giving the RHCE exam. Now you should boot your System properly. When you started your System, You got one message that.
INIT Entering runlevel 9 -
INIT: no more processes left in this runlevel
How will you boot your System properly?
Answer : You should know about the /etc/inittab file, where default runlevel will define. And Much more runlevel specific Scripts are called here. Actually that problem will occur if you don't specify the default runlevel. 1. Reboot the system 2. Boot the System on single user mode. Except for a normal boot of Linux, single-user mode is the most commonly used option. This is the system maintenance mode for experienced Linux administrators. It allows you to perform clean backups and restores to any partitions as needed from local hardware. It also allows you to run administration commands, recover or repair password and shadow password files, run filesystem checks, and so forth. 3. vi /etc/inittab and Write Standard Runlevels in RedHat Enterprise Linux Runlevel Description 0 Halt 1 Single-user mode, for maintenance (backups/restores) and repairs 2 Multiuser, without networking 3 Multiuser, with networking 4 Unused 5 X11, defaults to a GUI login screen. Logins bring the user to a GUI desktop. 6 Reboot (never set initdefault in /etc/inittab to this value!)
You are giving RHCE exam. You should boot the system in Run level 3. When you start the system after while it is going on runlevel 6 : like INIT: Entering Run level 6
Sending TERM Single -
Fix the problem and boot the system.
Answer : It is due to either default runlevel or runlevel specific scripts. Where default runlevel is specified. It shouldn't be 6. /etc/rc.d/rc 6 It reads the scripts of runlevel 6 while booting system on rulevel 3. /etc/rc.d/rc.sysinit /etc/rc.d/rc 0 /etc/rc.d/rc 1 /etc/rc.d/rc 2 /etc/rc.d/rc 3 Should be like this /etc/rc.d/rc 4 /etc/rc.d/rc 5 /etc/rc.d/rc 6
You are giving RHCE exam. Examiner gave you the Boot related problem and told to you that make successfully boot the System. While booting system, you saw some error and stop the boot process by displaying some error messages.
Kernel Panic - not syncing: Attempted to kill init!
And no further boot process. What you will do to boot the system.
Answer : To understand the role of a boot loader, take a step back from Linux. When you boot your computer, the BIOS starts by detecting basic hardware, including your hard drives. Once it's done, it looks for the boot loader on the Master Boot Record of the first available disk. If you're working with an older PC, the BIOS can't find your boot loader unless it's located within the first 1,024 cylinders of the hard disk. Newer BIOSes overcome this problem with Logical Block Addressing, which is also known as LBA mode. LBA mode reads 'logical' values for the cylinder, head, and sector, which allows the BIOS to 'see' a larger disk drive. If you have multiple hard drives, there is one more caveat. If your drives are IDE hard drives, the /boot directory must be on a hard drive attached to the primary IDE controller. If your drives are all SCSI hard drives, the /boot directory must be located on a hard drive with SCSI ID 0 or ID 1. If you have a mix of hard drives, the /boot directory must be located on either the first IDE drive or a SCSI drive with ID 0. In other words, this is not an issue on the Red Hat exams unless the computer that you're tested on has more than two hard drives. And I believe that's less likely, as that would increase the cost of the exam. If you are getting the Kernel panic error, it means it is boot loader related problem. Redhat Enterprise Linux uses the GRUB boot loader. You can pass the kernel parameter from the boot loader as well as you can correct the kernel parameter passing from boot loader from GRUB screen at boot time. /etc/grub.conf default=0 timeout=5 splashimage=(hd0,0)/grub/splash.xpm.gz hiddenmenu title Red Hat Enterprise Linux ES (2.6.9-5.EL) root (hd0,0) kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/ rhgb quiet initrd /initrd-2.6.9-5.EL.img Probably miss-configured the boot loader, so giving this problem. You can pass the correct GRUB Editing Commands Command Description b Boot the currently listed operati
You are giving RHCE exam. Examiner gave you the Boot related problem and told to you that make successfully boot the System. When you started the system, System automatically asking the root password for maintenance. How will you fix that problem?
Answer : Maintenance mode also known as emergency mode. System boots on emergency mode when file system error occurred. It is due to unknown partition, bad filesystem specified in /etc/fstab. To slove follow the steps 1. Give the Root password 2. fdisk -l Verify the Number of parations. 3. Identify the Root partition, e2label /dev/hda1, e2label /dev/hda2..... mount -o remount,defaults /dev/hda6 / 5. vi /etc/fstab Correct all partitions, mount point, mount options, file system etc. 6. Press ctrl+d
You are working as an Administrator. There is a common data shared (/data) from
192.168.0.254 to all users in your local LAN. When user's system start, shared data should automatically mount on /common directory.
Answer : To automatically mount at boot time we use the /etc/fstab file. Because /etc/rc.d/rc.sysinit file reads and mount all file system specified in /etc/fstab. To mount Network Sharing Files also use the /etc/fstab but filesystem is nfs. 1. vi /etc/fstab /data / common nfs defaults 0 0 2. reboot the system.
Boot your System Successfully on runlevel 3.
Answer : This is boot related problem. There will be same questions repeated two times but problem is different. error 15 mounting ext3 error 2 mounting none 22 2 Attempted to kill init ! This error occurred in your system before showing welcome redhat linux. That means problem in grub boot loader. Restart the System Check the grub boot loader configuration by pressing e shortcut key. root (hd0,0) kernel /vmlinuz-2.6.9-5.EL ro root= / rhgb quiet initrd /initrd-2.6.9-5.EL.img OR root (hd0,0) kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/root rhgb quiet initrd /initrd-2.6.9-5.EL.img Then Edit Boot loader to make like root (hd0,0) kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/ rhgb quiet i nitrd /initrd-2.6.9-5.EL.img Check all lines and edit as same as above. Press b to boot the system After booting the system you should correct the /etc/grub.conf file.
Boot your System Successfully on run level 3.
Answer : emergency mode. Remember that if System boots on Emergency mode that means file system problem. You will get the Shell, remount the / filesystem with read and write mode. 1. First Find out the / filesystem using e2lable /dev/hda1, e2lable /dev/hda2 etc 2. mount -o remount,defaults /dev/hda? / 3. vi /etc/fstab /root / ext3 defaults 1 1 or / /root ext3 defaults 1 1 / / ext3 defaults 1 1 5. Configure the /etc/grub.conf file if just booting system by editing grub from grub prompt. 6. Reboot the system.
Boot your System Successfully on runlevel 3. (Next Question)
Answer : This is boot related problem. There will be same questions repeated two times but problem is different. File Not Found error 15 mounting ext3 error 2 mounting none 22 2 Attempted to kill init ! Restart the System Check the grub boot loader configuration by pressing e shortcut key. root (hd0,0) kernel /vmlinuz-2.6.9-5.EL ro root= / rhgb quiet initrd /initrd-2.6.9-5.EL.img OR root (hd0,0) kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/root rhgb quiet initrd /initrd-2.6.9-5.EL.img Then Edit Boot loader to make like root (hd0,0) kernel /vmlinuz-2.6.9-5.EL ro root=LABEL=/ rhgb quiet initrd /initrd-2.6.9-5.EL.img Check all lines and edit as same as above. Press b to boot the system After booting the system you should correct the /etc/grub.conf file. If still you are getting Error like File not found, it seems that either kernel file or initrd file is missing. To troubleshoot with these problem, boot the system on rescue mode. i. linux rescue ii. chroot /mnt/sysimage iii. Check the files on /boot, if not available install the kernel package from ftp or nfs server mkinitrd initrd-2.6.9-5.EL.img `uname -r`
Install the Redhat Linux RHEL 5 through NFS. Where your Server is server1.example.com having IP 172.24.254.254 and shared /var/ftp/pub. The size of the partitions are listed below:
/ -> 1048
/home -> 1028
/boot -> 512
/var -> 1028
/usr -> 2048
Swap -> 1.5 of RAM Size -
/storage configure the RAID Level 0 of remaining all free space.
After completing the installation through NFS solve the following questions. There are two networks 172.24.0.0/16 and 172.25.0.0/16. As well as there are two domains example.com on 172.24.0.0/16 network and my133t.org on 172.25.0.0/16 network. Your system is based on example.com domain. SELinux should be in enforce mode.
Answer : 1. Insert the CD on CD-ROM and start the system. Prompt type linux askmethod 3. It will display the language, keyboard selection. 4. It will ask you for the installation method. 5. Select the NFS Image from the list 6. It will ask the IP Address, Net mask, Gateway and Name Server. Select Use because DHCP Server will be configured in your exam lab. 7. It will ask for the NFS Server Name and Redhat Enterprise Linux Directory. 172.24.254.254 /var/ftp/pub 8. After Connecting to the NFS Server Installation start in GUI. Go up to the partition screen by selecting the different Options. 9. Create the partition According to the Question because Size and what-what partition should you create at installation time is specified in your question 10. Create the two RAID partitions having equal size of remaining all free space. 11. Click on RAID button 12. Type mount point /data 13. Select RAID Level 0 14. Click on ok 15. Then select the MBR Options, time zone and go upto package selections. It is another Most Important Time of installation. Due to the time limit, you should care about the installation packages. At Exam time you these packages are enough. X-Window System GNOME Desktop (these two packages are generally not required) Administration Tools. System Tools Windows File Server FTP Servers Mail Servers Web Servers Network Servers Editors Text Based Internet Server Configuration Tools Base Printing Supports When installation will complete, your system will reboot. Jump for another Question.
Create the group named sysusers.
Answer : 1. groupadd sysusers groupadd command is used to create the group and all group information is stored in /etc/group file.
Create the user named jeff, marion, harold
Answer : 1. useradd jeff 2. useradd marion 3. useradd harold useradd command is used to create the user. All user's information stores in /etc/passwd and user;s shadow password stores in /etc/shadow.
Make Secondary belongs the jeff and marion users on sysusers group. But harold user should not belongs to sysusers group.
Answer : 1. useradd jeff 2. useradd marion 3. useradd harold useradd command is used to create the user. All user's information stores in /etc/passwd and user;s shadow password stores in /etc/shadow.
Answer: Explanation:
1. usermod -G sysusers jeff
2. usermod -G sysuser marion
3. Verify by reading /etc/group file
Using usermod command we can make user belongs to different group. There are two types of group one primary and another is secondary. Primary group can be only one but user can belongs to more than one group as secondary. usermod -g groupname username To change the primary group of the user usermod -G groupname username To make user belongs to secondary group.
Create the directory /storage and group owner should be the sysusers group.
Answer : 1. chgrp sysusers /storage 2. Verify using ls -ld /storage command. You should get like drwxr-x--- 2 root sysusers 4096 59 /storage chgrp command is used to change the group ownership of particular files or directory. Another way you can use the chown command. sysusers /storage
Make on /storage directory that only the user owner and group owner member can fully access.
Answer : 1. chmod 770 /storage ls -ld /storage 08 /storage To change the permission on directory we use the chmod command. According to the question that only the owner user (root) and group member (sysusers) can fully access the chmod 770 /archive
Who ever creates the files/directories on /storage group owner should be automatically should be the same group owner of /storage.
Answer : 1. chmod g+s /storage ls -ld /storage 08 /storage If SGID bit is set on directory then who every users creates the files on directory group owner automatically the owner of parent directory. chmod g+s directory chmod g-s directory
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