RH302 全真模擬試験 DEMO

問題7: mount /dev/hda? /mnt/neo
4. CORRECT TEXT
Your System is going use as a router for 172.24.0.0/16 and 172.25.0.0/16. Enable the IP
Forwarding.
正解:
1. echo "1" >/proc/sys/net/ipv4 /ip_forward
2. vi /etc/sysctl.conf
net.ipv4.ip_forward=1
/proc is the virtual filesystem, containing the information about the running kernel. To change the
parameter of running kernel you should modify on /proc. From Next reboot the system, kernel will
take the value from /etc/sysctl.conf.
5. CORRECT TEXT
Some users home directory is shared from your system. Using showmount -e localhost command,
the shared directory is not shown. Make access the shared users home directory.
正解:
1. Verify the File whether Shared or not ? : cat /etc/exports
2. Start the nfs service: service nfs start
3. Start the portmap service: service portmap start
4. Make automatically start the nfs service on next reboot: chkconfig nfs on
5. Make automatically start the portmap service on next reboot: chkconfig portmap on
6. Verify either sharing or not: showmount -e localhost
7. Check that default firewall is running on system ? if running flush the iptables using iptables -F
and stop the iptables service.
6. CORRECT TEXT
neo user tried by:
dd if=/dev/zero of=/home/neo/somefile bs=1024 count=70
files created successfully. Again neo tried to create file having 70K using following command:
dd if=/dev/zero of=/home/neo/somefile bs=1024 count=70
But he is unable to create the file. Make the user can create the file less then 70K.
正解:
Very Tricky question from redhat. Actually question is giving scenario to you to implement quota to
neo user. You should apply the quota to neo user on /home that neo user shouldn't occupied
space more than 70K.
1. vi /etc/fstab
LABEL=/home /home ext3 defaults,usrquota 0 0 To enable the quota on filesystem you should
mount the filesystem with usrquota for user quota and grpquota for group quota.
2. touch /home/aquota.user Creating blank quota database file.
3. mount -o remount /home Remounting the /home with updated mount options. You can verify
that /home is mounted with usrquota options or not using mount command.
4. quotacheck -u /home Initialization the quota on /home
5. edquota -u neo /home Quota Policy editor
See the snapshot
Disk quotas for user neo (uid 500):
Filesystem blocks soft hard inodes soft hard
/dev/mapper/vo-myvol 2 30 70 1 0 0
Can you set the hard limit 70 and soft limit as you think like 30.
Verify using the repquota /home command.
7. CORRECT TEXT
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.
正解:
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.
8. CORRECT TEXT
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).
正解:
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 /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.
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.
9. CORRECT TEXT
One Logical Volume named lv1 is created under vg0. The Initial Size of that Logical Volume is
100MB. Now you required the size 500MB. Make successfully the size of that Logical Volume
500M without losing any data. As well as size should be increased online.
正解:
The LVM system organizes hard disks into Logical Volume (LV) groups. Essentially, physical hard
disk partitions (or possibly RAID arrays) are set up in a bunch of equal-sized chunks known as
Physical Extents (PE). As there are several other concepts associated with the LVM system, let's
start with some basic definitions:
* Physical Volume (PV) is the standard partition that you add to the LVM mix. Normally, a physical
volume is a standard primary or logical partition. It can also be a RAID array.
* Physical Extent (PE) is a chunk of disk space. Every PV is divided into a number of equal sized
PEs. Every PE in a LV group is the same size. Different LV groups can have different sized PEs.
* Logical Extent (LE) is also a chunk of disk space. Every LE is mapped to a specific PE.
* Logical Volume (LV) is composed of a group of LEs. You can mount a filesystem such as /home
and /var on an LV.
* Volume Group (VG) is composed of a group of LVs. It is the organizational group for LVM. Most
of the commands that you'll use apply to a specific VG.
1. Verify the size of Logical Volume: lvdisplay /dev/vg0/lv1
2. Verify the Size on mounted directory: df -h or df -h mounted directory name
3. Use : lvextend -L+400M /dev/vg0/lv1
4. resize2fs /dev/vg0/lv1 to bring extended size online.
5. Again Verify using lvdisplay and df -h command.
10. CORRECT TEXT
Create one partitions having size 100MB and mount it on /data.
正解:
1. Use fdisk /dev/hda To create new partition.
2. Type n For New partitions
3. It will ask for Logical or Primary Partitions. Press l for logical.
4. It will ask for the Starting Cylinder: Use the Default by pressing Enter Key.
5. Type the Size: +100M You can Specify either Last cylinder of Size here.
6. Press P to verify the partitions lists and remember the partitions name.
7. Press w to write on partitions table.
8. Either Reboot or use partprobe command.
9. Use mkfs -t ext3 /dev/hda?
Or
mke2fs -j /dev/hda? To create ext3 filesystem.
10. vi /etc/fstab
Write:
/dev/hda? /data ext3 defaults 1 2
11. Verify by mounting on current Sessions also:
mount /dev/hda? /data
11. CORRECT TEXT
You are new System Administrator and from now you are going to handle the system and your
main task is Network monitoring, Backup and Restore. But you don't know the root password.
Change the root password to redhat and login in default Runlevel.
正解:
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.
1. Restart the System.
2. You will get the boot loader GRUB screen.
3. Press a and type 1 or s for single mode
ro root=LABEL=/ rhgb queit s
4. System will boot on Single User mode.
5. Use passwd command to change.
6. Press ctrl+d
12. CORRECT TEXT
There are more then 400 Computers in your Office. You are appointed as a System Administrator.
But you don't have Router. So, you are going to use your One Linux Server as a Router. How will
you enable IP packets forward?
正解:
1. /proc is the virtual filesystem, we use /proc to modify the kernel parameters at running time.
# echo "1" >/proc/sys/net/ipv4 /ip_forward
2. /etc/sysctl.conf when System Reboot on next time, /etc/rc.d/rc.sysinit scripts reads the file
/etc/sysctl.conf. To enable the IP forwarding on next reboot also you need to set the parameter.
net.ipv4.ip_forward=1
Here 0 means disable, 1 means enable.
13. CORRECT TEXT
You Completely Install the Redhat Enterprise Linux 5 on your System. While start the system, it's
giving error to load X window System. How will you fix that problem and make boot successfully
run X Window System.
正解:
Think while Problems occurred on booting System on Runlevel 5 (X Window)./tmp is full or
notQuota is already reachedVideo 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 filequota 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.
14. CORRECT TEXT
There are two different networks, 192.168.0.0/ 24 and 192.168.1.0/ 24. Your System is in
192.168.0.0/ 24 Network. One RHEL 5 Installed System is going to use as a Router. All required
configuration is already done on Linux Server. Where 192.168.0.254 and 192.168.1.254 IP
Address are assigned on that Server. How will make successfully ping to 192.168.1.0/ 24
Network's Host?
正解:
1. vi /etc/sysconfig/network
GATEWAY=192.168.0.254
OR
vi /etc/sysconf/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=static
ONBOOT=yes
IPADDR=192.168.0.?
NETMASK=255.255.255.0
GATEWAY=192.168.0.254
2. service network restart
15. CORRECT TEXT
Make a swap partition having 100MB. Make Automatically Usable at System Boot Time.
正解:
1. Use fdisk /dev/hda To create new partition.
2. Type n For New partition
3. It will ask for Logical or Primary Partitions. Press l for logical.
4. It will ask for the Starting Cylinder: Use the Default by pressing Enter Key.
5. Type the Size: +100M You can Specify either Last cylinder of Size here.
6. Press P to verify the partitions lists and remember the partitions name. Default System ID is 83
that means Linux Native.
7. Type t to change the System ID of partition.
8. Type Partition Number
9. Type 82 that means Linux Swap.
10. Press w to write on partitions table.
11. Either Reboot or use partprobe command.
12. mkswap /dev/hda? To create Swap File system on partition.
13. swapon /dev/hda? To enable the Swap space from partition.
14. free -m Verify Either Swap is enabled or not.
15. vi /etc/fstab
/dev/hda? swap swap defaults 0 0
16. Reboot the System and verify that swap is automatically enabled or not.