Role-specific Red Hat Certification Interview Questions & Answers:

1. Write a shell code for a sub-routine system call that will use majorly the ax register to prevent null character in virus coding?

2. Explain Both RAID level 0 and Linear RAID provide capacity equivalent to the amount of storage you have. In other
words, there is no space reserved for parity or error checking. What, then, is the difference between RAID
level 0 and Linear RAID?
A. When using Linear RAID, data is not striped across drives.
B. When using Linear RAID, data is striped across drives.
C. RAID 0 provides some amount of error checking.
D. Linear RAID provides some amount of redundancy.

A. When using Linear RAID, data is not striped across drives.

3. Which of the following is a journaling filesystem?
A. ext2
B. vfat
C. minix
D. ext3

D. ext3

4. Explain What DHCP server option is used to specify the DNS server to clients?
A. domain-name-servers
B. dns
C. domain-name
D. routers

A. domain-name-servers

5. Do you know One Logical Volume is created named as myvol under vo volume group and is
mounted. The Initial Size of that Logical Volume is 124MB. Make successfully that
the size of Logical Volume 245MB without losing any data. The size of logical
volume 240MB to 255MB will be acceptable.

1. First check the size of Logical Volume: lvdisplay /dev/vo/myvol
2. Increase the Size of Logical Volume: lvextend -L+121M /dev/vo/myvol
3. Make Available the size on online: resize2fs /dev/vo/myvol
4. Verify the Size of Logical Volume: lvdisplay /dev/vo/myvol
5. Verify that the size comes in online or not: df -h
We can extend the size of logical Volume using the lvextend command. As well as to
decrease the size of Logical Volume, use the lvresize command. In LVM v2 we can
extend the size of Logical Volume without unmount as well as we can bring the actual
size of Logical Volume on online using ext2online command.

6. Explain In order to set the time zone to US/Eastern via Kickstart, what must be in the Kickstart configuration file?
A. tz US/Eastern
B. timezone US/Eastern
C. It is not possible to set time zone
D. timeconfig US/Eastern

B. timezone US/Eastern

7. Suppose You are a System administrator. Using Log files very easy to monitor the system.
Now there are 50 servers running as Mail, Web, Proxy, DNS services etc. You want
to centralize the logs from all servers into on LOG Server. How will you configure
the LOG Server to accept logs from remote host?

By Default system accept the logs only generated from local host. To accept the Logfrom other host configure:
1. 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
2. service syslog restart

8. Explain One Package named zsh is dump on ftp://server1.example.com under /pub/updates
directory and your FTP server is 192.168.0.254. Install the package zsh.

1. rpm -ivh ftp://server1/example.com/pub/updates/zsh-*
or
1. Login to ftp server : ftp ftp://server1.example.com using anonymous user.
2. Change the directory: cd pub and cd updates
3. Download the package: mget zsh-*
4. Quit from the ftp prompt : bye
5. Install the package
6. rpm -ivh zsh-*
7. Verify either package is installed or not : rpm -q zsh

9. Do you know Quota is implemented on /data but not working properly. Find out the
Problem and implement the quota to user1 to have a soft limit 60 inodes
(files) and hard limit of 70 inodes (files).

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 kilobytesized
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 /data ext3 defaults,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.

10. Tell me The System you are using is for NFS (Network File Services). Some important data
are shared from your system. Make automatically start the nfs and portmap
services at boot time.

We can control the services for current session and for next boot time also. For current
Session, we use service servicename start or restart or stop or status. For automatically on
next reboot time:
1. chkconfig servicename on or off
eg: chkconfig nfs on
chkconfig portmap on
or
ntsysv
Select the nfs and portmap services.
2. Reboot the system and identify whether services are running or not.