RHCSA考试（Linux7）

按“e”进入编辑模式
在utf-8后面添加空格 rd.break
Ctrl + x执行

以读写权限重新挂载硬盘上的真实系统根目录：
mount -o remount,rw / /sysroot
切换至真实系统根目录：
chroot /sysroot
按要求修改root密码：
echo 123456 | passwd --stdin root
重新打标：
touch /.autorelabel
退出真实系统：
exit
退出系统重新引导：
exit
以新密码登录系统

[root@server0 ~]# hostnamectl set-hostname server0.example.com
[root@server0 ~]# bash
[root@server0 ~]# hostname
server0.example.com
[root@server0 ~]#

[root@server0 ~]# nmcli connection modify eth0 ipv4.addresses "172.25.0.11/24 172.25.0.254" ipv4.dns "172.25.254.254" connection.autoconnect yes ipv4.method manual
[root@server0 ~]# nmcli connection reload
[root@server0 ~]# service network restart
Restarting network (via systemctl): [ OK ]
[root@server0 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=none
ONBOOT=yes
TYPE=Ethernet
USERCTL=yes
IPV6INIT=no
NAME=eth0
PERSISTENT_DHCLIENT=
IPADDR0=172.25.0.11
PREFIX0=
GATEWAY0=172.25.0.254
DNS1=172.25.254.254
DOMAIN=server0.example.com
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
UUID=5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03
[root@server0 ~]#

[root@server0 ~]# setenforce 1
[root@server0 ~]# getenforce
Enforcing
[root@server0 ~]#
[root@server0 ~]# vim /etc/selinux/config 

[root@server0 ~]# reboot

[root@server0 ~]# yum-config-manager --help | grep add
--downloaddir=DLDIR
--add-repo=ADDREPO add (and enable) the repo from the specified file or
[root@server0 ~]# yum-config-manager --add-repo="http://classroom.example.com/content/rhel7.0/x86_64/dvd/"
Loaded plugins: langpacks
adding repo from: http://classroom.example.com/content/rhel7.0/x86_64/dvd/[classroom.example.com_content_rhel7.0_x86_64_dvd_]
name=added from: http://classroom.example.com/content/rhel7.0/x86_64/dvd/
baseurl=http://classroom.example.com/content/rhel7.0/x86_64/dvd/
enabled=[root@server0 ~]# echo "gpgcheck=0">>/etc/yum.repos.d/classroom.example.com_content_rhel7.0_x86_64_dvd_.repo
[root@server0 ~]# yum clean all
Loaded plugins: langpacks
Cleaning repos: classroom.example.com_content_rhel7.0_x86_64_dvd_ rhel_dvd
Cleaning up everything
[root@server0 ~]# yum makecache
Loaded plugins: langpacks
classroom.example.com_content_rhel7.0_x86_64_dvd_ | 4.1 kB ::
rhel_dvd | 4.1 kB ::
(/): classroom.example.com_content_rhel7.0_x86_64_dvd_/group_gz | kB ::
(/): classroom.example.com_content_rhel7.0_x86_64_dvd_/primary_db | 3.4 MB ::
(/): classroom.example.com_content_rhel7.0_x86_64_dvd_/other_db | 1.3 MB ::
(/): classroom.example.com_content_rhel7.0_x86_64_dvd_/productid | 1.6 kB ::
(/): classroom.example.com_content_rhel7.0_x86_64_dvd_/filelists_db | 3.0 MB ::
(/): rhel_dvd/group_gz | kB ::
(/): rhel_dvd/primary_db | 3.4 MB ::
(/): rhel_dvd/other_db | 1.3 MB ::
(/): rhel_dvd/filelists_db | 3.0 MB ::
Metadata Cache Created
[root@server0 ~]# yum repolist
Loaded plugins: langpacks
repo id repo name status
classroom.example.com_content_rhel7.0_x86_64_dvd_ added from: http://classroom.example.com/content/ 4,305
rhel_dvd Remote classroom copy of dvd ,
repolist: ,
[root@server0 ~]#

[root@server0 ~]# fdisk /dev/vdb
Welcome to fdisk (util-linux 2.23.).Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0x095042ab.Command (m for help): pDisk /dev/vdb: 10.7 GB, bytes, sectors
Units = sectors of * = bytes
Sector size (logical/physical): bytes / bytes
I/O size (minimum/optimal): bytes / bytes
Disk label type: dos
Disk identifier: 0x095042ab Device Boot Start End Blocks Id SystemCommand (m for help): n
Partition type:
p primary ( primary, extended, free)
e extended
Select (default p): e
Partition number (-, default ):
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ): +1G
Partition of type Extended and of size GiB is setCommand (m for help): n
Partition type:
p primary ( primary, extended, free)
l logical (numbered from )
Select (default p): l
Adding logical partition
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ):
Using default value
Partition of type Linux and of size MiB is setCommand (m for help): t
Partition number (,, default ):
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'Command (m for help): w
The partition table has been altered!Calling ioctl() to re-read partition table.
Syncing disks.
[root@server0 ~]# partprobe
[root@server0 ~]#

[root@server0 ~]# pvcreate /dev/vdb5
Physical volume "/dev/vdb5" successfully created
[root@server0 ~]# vgcreate --help | grep size
[-s|--physicalextentsize PhysicalExtentSize[bBsSkKmMgGtTpPeE]]
[root@server0 ~]# vgcreate vg0 -s 16M /dev/vdb5
Volume group "vg0" successfully created
[root@server0 ~]# vgdisplay
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas
Metadata Sequence No
VG Access read/write
VG Status resizable
MAX LV
Cur LV
Open LV
Max PV
Cur PV
Act PV
VG Size 1008.00 MiB
PE Size 16.00 MiB
Total PE
Alloc PE / Size /
Free PE / Size / 1008.00 MiB
VG UUID jvZd9h-nV9v-ankV-skjP-btgB-vF8R-W67IRT[root@server0 ~]# lvcreate -n lv0 -l 16 vg0
Logical volume "lv0" created
[root@server0 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/vg0/lv0
LV Name lv0
VG Name vg0
LV UUID n8oBJF-9caQ-COg8-2peS-pWTz-mQDj-rXHUKL
LV Write Access read/write
LV Creation host, time server0.example.com, -- :: +
LV Status available
# open
LV Size 256.00 MiB
Current LE
Segments
Allocation inherit
Read ahead sectors auto
- currently set to
Block device :[root@server0 ~]# mkfs.xfs /dev/vg0/lv0
meta-data=/dev/vg0/lv0 isize= agcount=, agsize= blks
= sectsz= attr=, projid32bit=
= crc=
data = bsize= blocks=, imaxpct=
= sunit= swidth= blks
naming =version bsize= ascii-ci= ftype=
log =internal log bsize= blocks=, version=
= sectsz= sunit= blks, lazy-count=
realtime =none extsz= blocks=, rtextents=
[root@server0 ~]#

[root@server0 ~]# mkdir -p /mnt/lvm
[root@server0 ~]# blkid
/dev/vda1: UUID="9bf6b9f7-92ad-441b-848e-0257cbb883d1" TYPE="xfs"
/dev/vdb5: UUID="KydhrK-3Nar-ktHy-b6Gq-skNj-sIQu-MgWCmm" TYPE="LVM2_member"
/dev/mapper/vg0-lv0: UUID="11ddc813-2a94-46f7-a7de-e735eb8bfe8c" TYPE="xfs"
[root@server0 ~]# echo "UUID="11ddc813-2a94-46f7-a7de-e735eb8bfe8c" /mnt/lvm xfs defaults 0 0">>/etc/fstab
[root@server0 ~]# mount -av
/ : ignored
mount: /mnt/lvm does not contain SELinux labels.
You just mounted an file system that supports labels which does not
contain labels, onto an SELinux box. It is likely that confined
applications will generate AVC messages and not be allowed access to
this file system. For more details see restorecon() and mount().
/mnt/lvm : successfully mounted
[root@server0 ~]# df -lh | grep lv0
/dev/mapper/vg0-lv0 253M 13M 240M % /mnt/lvm
[root@server0 ~]#

[root@server0 ~]# lvextend -L 384M /dev/vg0/lv0
Extending logical volume lv0 to 384.00 MiB
Logical volume lv0 successfully resized
[root@server0 ~]# xfs_growfs /dev/vg0/lv0
meta-data=/dev/mapper/vg0-lv0 isize= agcount=, agsize= blks
= sectsz= attr=, projid32bit=
= crc=
data = bsize= blocks=, imaxpct=
= sunit= swidth= blks
naming =version bsize= ascii-ci= ftype=
log =internal bsize= blocks=, version=
= sectsz= sunit= blks, lazy-count=
realtime =none extsz= blocks=, rtextents=
data blocks changed from to
[root@server0 ~]# df -lh | grep lv0
/dev/mapper/vg0-lv0 381M 14M 368M % /mnt/lvm
[root@server0 ~]#

[root@server0 ~]# groupadd --help | grep id
-g, --gid GID use GID for the new group
-K, --key KEY=VALUE override /etc/login.defs defaults
[root@server0 ~]# groupadd -g 40000 adminuser
[root@server0 ~]# cat /etc/group | grep 4000
adminuser:x::
[root@server0 ~]# useradd --help | grep group
-g, --gid GROUP name or ID of the primary group of the new
-G, --groups GROUPS list of supplementary groups of the new
-N, --no-user-group do not create a group with the same name as
-U, --user-group create a group with the same name as the user
[root@server0 ~]# useradd -G adminuser natasha
[root@server0 ~]# useradd -G adminuser harry
[root@server0 ~]# useradd --help | grep shell
-s, --shell SHELL login shell of the new account
[root@server0 ~]# useradd -s /sbin/nologin sarah
[root@server0 ~]# cat /etc/passwd | grep sarah
sarah:x::::/home/sarah:/sbin/nologin
[root@server0 ~]# echo rehat | passwd --stdin natasha
Changing password for user natasha.
passwd: all authentication tokens updated successfully.
[root@server0 ~]# echo rehat | passwd --stdin harry
Changing password for user harry.
passwd: all authentication tokens updated successfully.
[root@server0 ~]# echo rehat | passwd --stdin sarah
Changing password for user sarah.
passwd: all authentication tokens updated successfully.
[root@server0 ~]#

[root@server0 ~]# cp -a /etc/fstab /var/tmp/
[root@server0 ~]# chown root:root /var/tmp/fstab
[root@server0 ~]# chmod a-x /var/tmp/fstab
[root@server0 ~]# setfacl -Rm u:natasha:rw,u:harry:-- /var/tmp/fstab
[root@server0 ~]# chmod a+r /var/tmp/fstab
[root@server0 ~]# getfacl /var/tmp/fstab
getfacl: Removing leading '/' from absolute path names
# file: var/tmp/fstab
# owner: root
# group: root
user::rw-
user:natasha:rw-
user:harry:---
group::r--
mask::rw-
other::r--[root@server0 ~]#

[root@server0 ~]# crontab -e -u natasha
[root@server0 ~]# crontab -l -u natasha
# mim hour day month week command
* * * /bin/echo "rhcsa"[root@server0 ~]#

[root@server0 ~]# mkdir /home/admins
[root@server0 ~]# chgrp adminuser /home/admins/
[root@server0 ~]# chmod g=rwx,o=-- /home/admins/
[root@server0 ~]# chmod g+s /home/admins/
[root@server0 ~]# ls -ld /home/admins/
drwxrws---. root adminuser Dec : /home/admins/
[root@server0 ~]# getfacl /home/admins/
getfacl: Removing leading '/' from absolute path names
# file: home/admins/
# owner: root
# group: adminuser
# flags: -s-
user::rwx
group::rwx
other::---
[root@server0 ~]#

[root@server0 ~]# curl -s http://classroom.example.com/content/rhel7.0/x86_64/errata/Packages/ | grep kernel
<tr><td valign="top"><img src="/icons/unknown.gif" alt="[ ]"></td><td><a href="kernel-3.10.0-123.1.2.el7.x86_64.rpm">kernel-3.10.-123.1...&gt;</a></td><td align="right">-- : </td><td align="right"> 29M</td><td>&nbsp;</td></tr>
<tr><td valign="top"><img src="/icons/unknown.gif" alt="[ ]"></td><td><a href="kernel-doc-3.10.0-123.1.2.el7.noarch.rpm">kernel-doc-3.10.-..&gt;</a></td><td align="right">-- : </td><td align="right"> 12M</td><td>&nbsp;</td></tr>
[root@server0 ~]# wget http://classroom.example.com/content/rhel7.0/x86_64/errata/Packages/kernel-3.10.0-123.1.2.el7.x86_64.rpm
---- ::-- http://classroom.example.com/content/rhel7.0/x86_64/errata/Packages/kernel-3.10.0-123.1.2.el7.x86_64.rpm
Resolving classroom.example.com (classroom.example.com)... 172.25.254.254
Connecting to classroom.example.com (classroom.example.com)|172.25.254.254|:... connected.
HTTP request sent, awaiting response... OK
Length: (29M) [application/x-rpm]
Saving to: ‘kernel-3.10.-123.1..el7.x86_64.rpm’%[=================================================>] ,, .1MB/s in .4s -- :: (82.1 MB/s) - ‘kernel-3.10.-123.1..el7.x86_64.rpm’ saved [/][root@server0 ~]# ls
anaconda-ks.cfg Documents kernel-3.10.0-123.1.2.el7.x86_64.rpm Pictures Templates
Desktop Downloads Music Public Videos
[root@server0 ~]# chmod 755 kernel-3.10.0-123.1.2.el7.x86_64.rpm
[root@server0 ~]# rpm -ivh kernel-3.10.0-123.1.2.el7.x86_64.rpm
warning: kernel-3.10.-123.1..el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID fd431d51: NOKEY
Preparing... ################################# [%]
Updating / installing...
:kernel-3.10.-123.1..el7 ################################# [%]
[root@server0 ~]# grub2-editenv list
saved_entry=Red Hat Enterprise Linux Server (3.10.-123.1..el7.x86_64) 7.0 (Maipo)
[root@server0 ~]# reboot

[root@server0 ~]# yum install authconfig-gtk sssd krb5-workstation -y
[root@server0 ~]# authconfig-gtk

上面配置完成再进行（没有配置的话sssd服务无法启动）：
[root@server0~]# systemctl enable sssd
[root@server0~]# systemctl restart sssd
[root@server0~]# systemctl status sssd
[root@server0~]# su ldapuser0
bash-4.2$
验证用户：ldapuser0

[root@server0 ~]# systemctl restart sssd
[root@server0 ~]# su ldapuser0
bash-4.2$ exit
exit
[root@server0 ~]# getent passwd ldapuser0
ldapuser0:*:1700:1700:LDAP Test User 0:/home/guests/ldapuser0:/bin/bash
[root@server0 ~]#

[root@server0 ~]# yum install autofs -y
[root@server0 ~]# systemctl enable autofs.service

[root@server0 ~]# cp -a /etc/auto.misc /etc/auto.aa
[root@server0 ~]# echo "/home/guests /etc/auto.aa" >>/etc/auto.master
[root@server0 ~]# echo "* -type=nfs,rw classroom.example.com:/home/guests/&">>/etc/auto.aa
[root@server0 ~]# systemctl restart autofs.service
[root@server0 ~]# ssh ldapuser0@localhost
ldapuser0@localhost's password: （kerberos）
Last login: Wed Dec :: from localhost
[ldapuser0@server0 ~]$ cd /home/guests/
[ldapuser0@server0 guests]$ ls
ldapuser0
[ldapuser0@server0 guests]$

[root@server0 ~]# systemctl enable chronyd
[root@server0 ~]# systemctl restart chronyd.service
[root@server0 ~]# chronyc sources -v
Number of sources = .-- Source mode '^' = server, '=' = peer, '#' = local clock.
/ .- Source state '*' = current synced, '+' = combined , '-' = not combined,
| / '?' = unreachable, 'x' = time may be in error, '~' = time too variable.
|| .- xxxx [ yyyy ] +/- zzzz
|| / xxxx = adjusted offset,
|| Log2(Polling interval) -. | yyyy = measured offset,
|| \ | zzzz = estimated error.
|| | |
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^* classroom.example.com +796ns[ -21us] +/- 1176us
[root@server0 ~]#

[root@server0 ~]# man tar | grep zip2
-j, --bzip2
filter the archive through bzip2
-j, --bzip2
filter the archive through bzip2
[root@server0 ~]# tar -jcf /root/sysconfg.tar.bz2 /etc/sysconfig/

[root@server0 ~]# useradd -u 3456 jay
[root@server0 ~]# echo "glegunge"|passwd --stdin jay
Changing password for user jay.
passwd: all authentication tokens updated successfully.
[root@server0 ~]# id jay
uid=(jay) gid=(jay) groups=(jay)
[root@server0 ~]#

[root@server0 ~]# fdisk /dev/vdb
Welcome to fdisk (util-linux 2.23.).Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.Command (m for help): n
Partition type:
p primary ( primary, extended, free)
l logical (numbered from )
Select (default p): p
Partition number (-, default ):
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ): +512M
Partition of type Linux and of size MiB is setCommand (m for help): t
Partition number (,,, default ):
Hex code (type L to list all codes):
Changed type of partition 'Linux' to 'Linux swap / Solaris'Command (m for help): w
The partition table has been altered!Calling ioctl() to re-read partition table.WARNING: Re-reading the partition table failed with error : Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe() or kpartx()
Syncing disks.
[root@server0 ~]# partprobe
[root@server0 ~]# mkswap /dev/vdb2
Setting up swapspace version , size = KiB
no label, UUID=b9a7e4a8-66f9-4de0-8d3e-f09a7844fa69
[root@server0 ~]# swapon -av /dev/vdb2
swapon /dev/vdb2
swapon: /dev/vdb2: found swap signature: version , page-size , same byte order
swapon: /dev/vdb2: pagesize=, swapsize=, devsize=
[root@server0 ~]# echo "UUID=b9a7e4a8-66f9-4de0-8d3e-f09a7844fa69 swap swap defults 0 0">>/etc/fstab
[root@server0 ~]# mount -av
/ : ignored
/mnt/lvm : already mounted
swap : ignored

[root@server0 ~]# free -lh | grep Swap
  Swap:     511M      0B           511M
  [root@server0 ~]#

[root@server0 ~]# mkdir /root/findfiles -p
[root@server0 ~]# find / -user jay -exec cp -a {} /root/findfiles/ \;
find: ‘/proc//task//fd/’: No such file or directory
find: ‘/proc//task//fdinfo/’: No such file or directory
find: ‘/proc//fd/’: No such file or directory
find: ‘/proc//fdinfo/’: No such file or directory
find: ‘/home/guests/ldapuser0’: Permission denied
cp: cannot overwrite non-directory ‘/root/findfiles/jay’ with directory ‘/home/jay’
[root@server0 ~]# ls -l /root/findfiles/
total
drwxr-xr-x. jay jay Jan extensions
-rw-r--r--. jay jay Jul gnome-initial-setup-done
-rw-rw----. jay mail Dec : jay
-rw-r--r--. jay jay Jul monitors.xml
drwxr-xr-x. jay jay Jan plugins
[root@server0 ~]#

[root@server0 ~]# grep seismic /usr/share/dict/words | grep -v ^$ >/root/wordlist