Pass the RedHat RHCE RH302 Questions and answers with ExamsMirror

When you Boot the System, it starts on default Runlevel specified in /etc/inittab:

Id:?:initdefault:

When System Successfully boot, it will ask for username and password. But you don’t know the root’s password. To change the root password you need to boot the system into single user mode. You can pass the kernel arguments from the boot loader.

Restart the System.

You will get the boot loader GRUB screen.

Press a and type 1 or s for single mode

ro root=LABEL=/ rhgb queit s

System will boot on Single User mode.

Use passwd command to change.

Press ctrl+d

By Default system accept the logs only generated from local host. To accept the Log from other host configure:

vi /etc/sysconfig/syslog

SYSLOGD_OPTIONS="-m 0 -r"

Where

-m 0 disables 'MARK' messages.

-r enables logging from remote machines

-x disables DNS lookups on messages recieved with -r

service syslog restart

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

Give the Root password

fdisk –lVerify the Number of parations.

Identify the Root partition, e2label /dev/hda1, e2label /dev/hda2…..

Remount the root partation on rw mode: mount –o remount,defaults /dev/hda6 /

vi /etc/fstab

Correct all partitions, mount point, mount options, file system etc.

6.Press ctrl+d

This is boot related problem. There will be same questions repeated two times but problem is different.

First When you restart the system you will get the Error:

mount: error 15 mounting ext3

mount: error 2 mounting none

switchroot: mount failed: 22

umount /initrd/dev/: 2

Kernel Panic: no syncing: 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.

You will see like:

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.

After completing the Boot loader problem, you will boot the system, but it goes to 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

You will get like:

/root/ext3defaults 1 1

or //rootext3defaults 1 1

4.Edit the file like:

//ext3defaults 1 1

5.Configure the /etc/grub.conf file if just booting system by editing grub from grub prompt.

6.Reboot the system.

In Network problem thinks to check:

IP Configuration: use ifconfig command either IP is assigned to interface or not?

Default Gateway is set or not?

Hostname is set or not?

Routing problem is there?

Device Driver Module is loaded or not?

Device is activated or not?

Check In this way:

use ifconfig command and identify which IP is assigned or not.

cat /etc/sysconfig/networkWhat, What is written here. Actually here are these parameters.

NETWORKING=yes or no

GATEWAY=x.x.x.x

HOSTNAME=?

NISDOMAIN=?

Correct the file

Use vi /etc/sysconfig/network-scirpts/ifcfg-eth0 and check the proper options

DEVICE=eth0

ONBOOT=yes

BOOTPROTO=static

IPADDR=x.x.x.x

NETMAKS=x.x.x.x

GATEWAY=x.x.x.x

Use service network restart or start command

Do the following steps as:

vi /etc/resolv.conf

nameserver 172.24.254.254

host server1.example.com

Do the following steps as:

hostname station?.example.comThis will set the host name only for current session. To set hostname permanently.

vi /etc/sysconfig/network

HOSTNAME=station?.example.com

service network restart

Do the following steps as:

Think while Problems occurred on booting System on Runlevel 5 (X Window).

/tmp is full or not

Quota is already reached

Video card or resolution or monitor is misconfigured.

xfs service is running or not.

Do These:

1.df –h /tmp/tmp is full remove the unnecessary file

quota usernameif quota is already reached remove unnecessary file from home directory.

Boot the System in runlevel 3.you can pass the Kernel Argument from boot loader.

Use command: system-config-displayIt will display a dialog to configure the monitor, Video card, resolution etc.

Set the Default Runlevel 5 in /etc/inittab

id:5:initdefault:

6.Reboot the System you will get the GUI login Screen.

Quotas are used to limit a user's or a group of users' ability to consume disk space. This prevents a small group of users from monopolizing disk capacity and potentially interfering with other users or the entire system. Disk quotas are commonly used by ISPs, by Web hosting companies, on FTP sites, and on corporate file servers to ensure continued availability of their systems.

Without quotas, one or more users can upload files on an FTP server to the point of filling a filesystem. Once the affected partition is full, other users are effectively denied upload access to the disk. This is also a reason to mount different filesystem directories on different partitions. For example, if you only had partitions for your root (/) directory and swap space, someone uploading to your computer could fill up all of the space in your root directory (/). Without at least a little free space in the root directory (/), your system could become unstable or even crash.

You have two ways to set quotas for users. You can limit users by inodes or by kilobyte-sized disk blocks. Every Linux file requires an inode. Therefore, you can limit users by the number of files or by absolute space. You can set up different quotas for different filesystems. For example, you can set different quotas for users on the /home and /tmp directories if they are mounted on their own partitions.

Limits on disk blocks restrict the amount of disk space available to a user on your system. Older versions of Red Hat Linux included LinuxConf, which included a graphical tool to configure quotas. As of this writing, Red Hat no longer has a graphical quota configuration tool. Today, you can configure quotas on RHEL only through the command line interface.

1. vi /etc/fstab

/dev/hda11/dataext3defaults,usrquota 1 2

2. Either Reboot the System or remount the partition.

Mount –o remount /dev/hda11 /data

3. touch /data/aquota.user

4. quotacheck –ufm /data

5. quotaon -u /data

6. edquota –u user1 /data

and Specified the Soft limit and hard limit on opened file.

To verify either quota is working or not:

Soft limit specify the limit to generate warnings to users and hard limit can’t cross by the user. Use the quota command or repquota command to monitor the quota information.