EX200 Korean 無料問題集「RedHat Red Hat Certified System Administrator - RHCSA (EX200 Korean Version)」

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 file system 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.
Verify the size of Logical Volume: lvdisplay /dev/vg0/lv1
Verify the Size on mounted directory: df -h or df -h mounted directory name Use: lvextend -L+400M /dev/vg0/lv1 ext2online -d /dev/vg0/lv1 to bring extended size online.
Again Verify using lvdisplay and df -h command.

# chkconfig autofs on
# cd /etc/
# vim /etc/auto.master
/rhome /etc/auto.ldap
# cp auto.misc auto.ldap
# vim auto.ladp
ldapuser40 -rw,soft,intr 172.24.40.10:/rhome/ldapuser40
* -rw,soft,intr 172.16.40.10:/rhome/&
# service autofs stop
# server autofs start
# showmount -e 172.24.40.10
# su - ladpuser40

# cd /opt/
# mkdir dir
# find / -user harry -exec cp -rfp {} /opt/dir/ \;

[root@node1 ~]# find / -name natasha -type f > /home/natasha/files
[root@node1 ~]# cat /home/natasha/files
/var/spool/mail/natasha
/mnt/shares/natasha
[root@node1 ~]# mkdir /find
[root@node1 ~]# find /etc -size +5M > /find/largefiles
[root@node1 ~]# cat /find/largefiles
/etc/selinux/targeted/policy/policy.31
/etc/udev/hwdb.bin

useradd eric
passwd eric
vi /etc/passwd
eric:x:505:505::/home/eric:/sbin/nologin
Which shell or program should start at login time is specified in /etc/passwd file? By default, Redhat Enterprise Linux assigns the /bin/bash shell to the users. To deny the interactive login, you should write /sbin/nologin or /bin/ false instead of login shell.

mkdir /home/admins
chgrp -R adminuser /home/admins
chmodg+w /home/admins
chmodg+s /home/admins

mkdir -p /home/guests
cat /etc/auto.master:
/home/guests /etc/auto.ldap
cat /etc/auto.ldap:
ldapuser1 -rw instructor.example.com:/home/guests/ldapuser1
automatically mount all the user's home directory #* -rw instructor.example.com:/home/guests/&

* 1. Reboot the server pressing by Ctrl+Alt+Del
2. When the boot-loader menu appears, press the cursor keys to highlight the default boot-loader entry
3. Press e to edit the current entry.
4. Use the cursor keys to navigate to the line that starts with linux.
5. Press End to move the cursor to the end of the line.
6. Append rd.break to the end of the line.
7. Press Ctrl+x to boot using the modified configuration.
8. At the switch_root prompt
* switch_root:/# mount -o remount,rw /sysroot
switch_root:/# chroot /sysroot
sh-4.4# echo kexdrams | passwd --stdin root
Changing password for user root.
passwd: all authentication tokens updated successfully.
sh-4.4# touch /.autorelabel
sh-4.4# exit; exit
* Type exit twice to continue booting your system as usual.

ftp server.domain11.example.com Anonymous login
ftp> cd /pub/updates ftp> ls
ftp> mget kernel* ftp> bye
rpm -ivh kernel*
vim /etc/grub.conf
Check the updatted kernel is the first kernel and the orginal kernel remains available. set default=0 wq!

groupadd admin
useradd -G admin mary
useradd -G admin alice
useradd -s /sbin/nologin bobby
echo "password" | passwd --stdin mary
echo "password" | passwd --stdin alice
echo "password" | passwd --stdin bobby