第三周作业-N67044-张铭扬

1. 图文并茂说明raid0,raid1, raid10, raid01, raid5等原理。

“RAID”是指独立硬盘冗余阵列（RAID, Redundant Array of Independent Disks），简称磁盘阵列。它是利用虚拟化存储技术把多个硬盘组合起来，成为一个或多个硬盘阵列组，目的为提升性能或数据冗余，或是两者同时提升。

RAID有多种级别，级别不同表示磁盘组织在一起的工作方式有所不同。

1）RAID-0:RAID-0的组成至少需要两块磁盘，它是在所有级别中的速度是最快的，但是缺点也很明显，RAID-0既没有冗余功能，也没有容错能力。如果其中的一个磁盘出现损坏，那么所有的数据都会丢失。

 

2）RAID-1：RAID-1也称为镜像，是有两组以上的N个磁盘组成的，它将数据完全一致的写入工作磁盘和镜像磁盘中，互为备份。在一些多线程操作系统中能有很好的读取速度，在一些多线程操作系统中能有很好的读取速度，理论上读取速度等于硬盘数量的倍数，与RAID 0相同。但磁盘的容量没有提升，只有50%的利用率。

3)RAID-10:RAID-10是一种组合等级，是由多个RAID-1组合成为一个RAID-O,先做镜像再作条带化。由于该组合等级是先用RAID-1模式，所以磁盘利用率还是50%，但是读和写的性能都有提升，并且每组镜像能坏一块因磁盘的容错率。

4)RAID-01:RAID-01与RAID-10相反，它是由多块磁盘先组成RAID-0，再组合成RAID-1。在相同的配置下，RAID-01比RAID-10具有更好的容错率。

5)RAID-5:RAID-5是最常见的的RAID等级，它有多块数据盘异或运算值存于校验盘中，对于数据和校验数据，它们的写操作可以同时发生在完全不同的磁盘上。该等级至少3块硬盘才可以实现 。

2. 创建一个至少有两个PV组成的大小为20G的名为testvg的VG，要求PE大小为16M，而后在卷组中创建大小为5G的逻辑卷testlv;挂载至/users目录

1）创建PV

[root@centos8 dev]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0          11:0    1 10.1G  0 rom  
nvme0n1     259:0    0  200G  0 disk 
├─nvme0n1p1 259:1    0  100G  0 part /
├─nvme0n1p2 259:2    0   50G  0 part /data
├─nvme0n1p3 259:3    0    2G  0 part [SWAP]
├─nvme0n1p4 259:4    0    1K  0 part 
└─nvme0n1p5 259:5    0    1G  0 part /boot
nvme0n2     259:6    0   20G  0 disk 
nvme0n3     259:7    0   10G  0 disk 
[root@centos8 dev]# pvcreate /dev/nvme0n2
  Physical volume "/dev/nvme0n2" successfully created.
[root@centos8 dev]# pvcreate /dev/nvme0n3
  Physical volume "/dev/nvme0n3" successfully created.

2）创建VG

[root@centos8 dev]# vgcreate -s 16M testvg /dev/nvme0n2 /dev/nvme0n3
  Volume group "testvg" successfully created
[root@centos8 dev]# vgs
  VG     #PV #LV #SN Attr   VSize   VFree  
  testvg   2   0   0 wz--n- <29.97g <29.97g
[root@centos8 dev]# vgdisplay
  --- Volume group ---
  VG Name               testvg
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               <29.97 GiB
  PE Size               16.00 MiB
  Total PE              1918
  Alloc PE / Size       0 / 0   
  Free  PE / Size       1918 / <29.97 GiB
  VG UUID               1185ZS-uqRT-1GVR-ybCm-Ae4P-3Q99-fBeUv2

3）创建LV

[root@centos8 dev]# vgcreate -s 16M testvg /dev/nvme0n2 /dev/nvme0n3
  Volume group "testvg" successfully created
[root@centos8 dev]# vgs
  VG     #PV #LV #SN Attr   VSize   VFree  
  testvg   2   0   0 wz--n- <29.97g <29.97g
[root@centos8 dev]# vgdisplay
  --- Volume group ---
  VG Name               testvg
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               <29.97 GiB
  PE Size               16.00 MiB
  Total PE              1918
  Alloc PE / Size       0 / 0   
  Free  PE / Size       1918 / <29.97 GiB
  VG UUID               1185ZS-uqRT-1GVR-ybCm-Ae4P-3Q99-fBeUv2
   
[root@centos8 dev]# lvcreate -L 5G -n testlv textvg
  Volume group "textvg" not found
  Cannot process volume group textvg
[root@centos8 dev]# lvcreate -L 5G -n testlv testvg
  Logical volume "testlv" created.
[root@centos8 dev]# lvs
  LV     VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  testlv testvg -wi-a----- 5.00g                                                    
[root@centos8 dev]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/testvg/testlv
  LV Name                testlv
  VG Name                testvg
  LV UUID                2IYLSm-tPIH-zuTi-4LhB-3Vgj-Plo1-PNdrsp
  LV Write Access        read/write
  LV Creation host, time centos8.zhang.org, 2022-07-03 18:04:45 +0800
  LV Status              available
  # open                 0
  LV Size                5.00 GiB
  Current LE             320
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

4）挂载

[root@centos8 dev]# mkfs.ext4 /dev/testvg/testlv
mke2fs 1.45.6 (20-Mar-2020)
Creating filesystem with 1310720 4k blocks and 327680 inodes
Filesystem UUID: 9e81c723-a325-4a4e-8883-f05d56e1fd7c
Superblock backups stored on blocks: 
    32768, 98304, 163840, 229376, 294912, 819200, 884736

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done 

[root@centos8 dev]# mkdir /users
[root@centos8 ~]# mount /dev/testvg/testlv /users
[root@centos8 ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0              11:0    1 10.1G  0 rom  
nvme0n1         259:0    0  200G  0 disk 
├─nvme0n1p1     259:1    0  100G  0 part /
├─nvme0n1p2     259:2    0   50G  0 part /data
├─nvme0n1p3     259:3    0    2G  0 part [SWAP]
├─nvme0n1p4     259:4    0    1K  0 part 
└─nvme0n1p5     259:5    0    1G  0 part /boot
nvme0n2         259:6    0   20G  0 disk 
└─testvg-testlv 253:0    0    5G  0 lvm  /users
nvme0n3         259:7    0   10G  0 disk

3. 新建用户archlinux,要求其家目录为/users/archlinux，而后su切换至archlinux用户，复制/etc/pam.d/目录至自己的家目录。

[root@centos8 ~]# useradd -d /users/archlinux archlinux
[root@centos8 ~]# id archlinux
uid=1001(archlinux) gid=1001(archlinux) groups=1001(archlinux)
[root@centos8 ~]# su archlinux
[archlinux@centos8 root]$ echo $HOME
/users/archlinux
[archlinux@centos8 etc]$ cp -rp /etc/pam.d/ $HOME

4. 扩展testlv至7G，要求archlinux用户的文件不能丢失

[root@centos8 ~]# lvextend -L 7G /dev/testvg/testlv
  Size of logical volume testvg/testlv changed from 5.00 GiB (320 extents) to 7.00 GiB (448 extents).
  Logical volume testvg/testlv successfully resized.
[root@centos8 ~]# resize2fs /dev/testvg/testlv
resize2fs 1.45.6 (20-Mar-2020)
Filesystem at /dev/testvg/testlv is mounted on /users; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 1
The filesystem on /dev/testvg/testlv is now 1835008 (4k) blocks long.
[root@centos8 ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0              11:0    1 10.1G  0 rom  
nvme0n1         259:0    0  200G  0 disk 
├─nvme0n1p1     259:1    0  100G  0 part /
├─nvme0n1p2     259:2    0   50G  0 part /data
├─nvme0n1p3     259:3    0    2G  0 part [SWAP]
├─nvme0n1p4     259:4    0    1K  0 part 
└─nvme0n1p5     259:5    0    1G  0 part /boot
nvme0n2         259:6    0   20G  0 disk 
└─testvg-testlv 253:0    0    7G  0 lvm  /users
nvme0n3         259:7    0   10G  0 disk 
[root@centos8 ~]# ll /users/archlinux/pam.d/
total 120
-rw-r--r-- 1 archlinux archlinux 272 May 11  2019 atd
-rw-r--r-- 1 archlinux archlinux 192 Jul 21  2021 chfn
-rw-r--r-- 1 archlinux archlinux 192 Jul 21  2021 chsh
-rw-r--r-- 1 archlinux archlinux 728 Sep  9  2021 cockpit
-rw-r--r-- 1 archlinux archlinux 232 May  7  2021 config-util
-rw-r--r-- 1 archlinux archlinux 328 Nov  9  2019 crond
-r--r--r-- 1 archlinux archlinux 146 May 19  2021 cups
lrwxrwxrwx 1 archlinux archlinux  32 Jun 25 14:21 fingerprint-auth -> /etc/authselect/fingerprint-auth
-rw-r--r-- 1 archlinux archlinux 622 Mar 30  2021 gdm-autologin
-rw-r--r-- 1 archlinux archlinux 561 Mar 30  2021 gdm-fingerprint
-rw-r--r-- 1 archlinux archlinux 307 Mar 30  2021 gdm-launch-environment
-rw-r--r-- 1 archlinux archlinux 787 Mar 30  2021 gdm-password
-rw-r--r-- 1 archlinux archlinux 800 Mar 30  2021 gdm-pin
-rw-r--r-- 1 archlinux archlinux 553 Mar 30  2021 gdm-smartcard
-rw-r--r-- 1 archlinux archlinux 715 Jul 21  2021 login
-rw-r--r-- 1 archlinux archlinux 154 May  7  2021 other
-rw-r--r-- 1 archlinux archlinux 168 Apr  7  2020 passwd
lrwxrwxrwx 1 archlinux archlinux  29 Jun 25 14:21 password-auth -> /etc/authselect/password-auth
-rw-r--r-- 1 archlinux archlinux 155 Jun  2  2021 polkit-1
lrwxrwxrwx 1 archlinux archlinux  25 Jun 25 14:21 postlogin -> /etc/authselect/postlogin
-rw-r--r-- 1 archlinux archlinux 640 Jul 21  2021 remote
-rw-r--r-- 1 archlinux archlinux 143 Jul 21  2021 runuser
-rw-r--r-- 1 archlinux archlinux 138 Jul 21  2021 runuser-l
lrwxrwxrwx 1 archlinux archlinux  30 Jun 25 14:21 smartcard-auth -> /etc/authselect/smartcard-auth
-rw-r--r-- 1 archlinux archlinux 727 Jul 13  2021 sshd
-rw-r--r-- 1 archlinux archlinux 214 Aug 10  2021 sssd-shadowutils
-rw-r--r-- 1 archlinux archlinux 566 Jul 21  2021 su
-rw-r--r-- 1 archlinux archlinux 154 Oct 25  2021 sudo
-rw-r--r-- 1 archlinux archlinux 178 Oct 25  2021 sudo-i
-rw-r--r-- 1 archlinux archlinux 137 Jul 21  2021 su-l
lrwxrwxrwx 1 archlinux archlinux  27 Jun 25 14:21 system-auth -> /etc/authselect/system-auth
-rw-r--r-- 1 archlinux archlinux 248 Oct  5  2021 systemd-user
-rw-r--r-- 1 archlinux archlinux  84 Jul 21  2020 vlock
-rw-r--r-- 1 archlinux archlinux 159 May 27  2021 vmtoolsd
-rw-r--r-- 1 archlinux archlinux 163 Jun 11  2021 xserver

5. 收缩testlv至3G，要求archlinux用户的文件不能丢失

缩减有数据损坏的风险，建议先备份再缩减，xfs文件系统不支持缩减

1）备份

[root@centos8 data]# tar -cvf /data/user.tar /users/
tar: Removing leading `/' from member names
/users/
/users/archlinux/
/users/archlinux/.mozilla/
/users/archlinux/.mozilla/plugins/
/users/archlinux/.mozilla/extensions/
/users/archlinux/.bash_profile
/users/archlinux/.bashrc
/users/archlinux/.bash_logout
/users/archlinux/pam.d/
/users/archlinux/pam.d/chfn
/users/archlinux/pam.d/gdm-autologin
/users/archlinux/pam.d/gdm-launch-environment
/users/archlinux/pam.d/password-auth
/users/archlinux/pam.d/config-util
/users/archlinux/pam.d/other
/users/archlinux/pam.d/atd
/users/archlinux/pam.d/runuser
/users/archlinux/pam.d/xserver
/users/archlinux/pam.d/cups
/users/archlinux/pam.d/passwd
/users/archlinux/pam.d/postlogin
/users/archlinux/pam.d/sssd-shadowutils
/users/archlinux/pam.d/gdm-password
/users/archlinux/pam.d/gdm-smartcard
/users/archlinux/pam.d/fingerprint-auth
/users/archlinux/pam.d/su-l
/users/archlinux/pam.d/system-auth
/users/archlinux/pam.d/systemd-user
/users/archlinux/pam.d/chsh
/users/archlinux/pam.d/vmtoolsd
/users/archlinux/pam.d/polkit-1
/users/archlinux/pam.d/su
/users/archlinux/pam.d/smartcard-auth
/users/archlinux/pam.d/sshd
/users/archlinux/pam.d/login
/users/archlinux/pam.d/vlock
/users/archlinux/pam.d/sudo-i
/users/archlinux/pam.d/sudo
/users/archlinux/pam.d/gdm-pin
/users/archlinux/pam.d/remote
/users/archlinux/pam.d/cockpit
/users/archlinux/pam.d/runuser-l
/users/archlinux/pam.d/crond
/users/archlinux/pam.d/gdm-fingerprint
/users/lost+found/
[root@centos8 data]# ll 
total 52
-rw-r--r-- 1 root root 51200 Jul  3 18:47 user.tar

2）缩减

[root@centos8 data]# blkid /dev/testvg/testlv
/dev/testvg/testlv: UUID="9e81c723-a325-4a4e-8883-f05d56e1fd7c" BLOCK_SIZE="4096" TYPE="ext4"
[root@centos8 data]# lvs
  LV     VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  testlv testvg -wi-ao---- 7.00g                                                    
[root@centos8 data]# df
Filesystem                1K-blocks    Used Available Use% Mounted on
devtmpfs                     970016       0    970016   0% /dev
tmpfs                        998404       0    998404   0% /dev/shm
tmpfs                        998404    9692    988712   1% /run
tmpfs                        998404       0    998404   0% /sys/fs/cgroup
/dev/nvme0n1p1            104806400 5418152  99388248   6% /
/dev/nvme0n1p2             52403200  398452  52004748   1% /data
/dev/nvme0n1p5               999320  193944    736564  21% /boot
tmpfs                        199680      24    199656   1% /run/user/0
/dev/mapper/testvg-testlv   7159288   23180   6763212   1% /users

[root@centos8 data]# umount /users
[root@centos8 data]# resize2fs /dev/testvg/testlv 3G
resize2fs 1.45.6 (20-Mar-2020)
Please run 'e2fsck -f /dev/testvg/testlv' first.
[root@centos8 data]# fsck -f /dev/testvg/testlv
fsck from util-linux 2.32.1
e2fsck 1.45.6 (20-Mar-2020)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mapper/testvg-testlv: 54/458752 files (0.0% non-contiguous), 50981/1835008 blocks

[root@centos8 data]# resize2fs /dev/testvg/testlv 3G
resize2fs 1.45.6 (20-Mar-2020)
Resizing the filesystem on /dev/testvg/testlv to 786432 (4k) blocks.
The filesystem on /dev/testvg/testlv is now 786432 (4k) blocks long.
[root@centos8 data]# lvs
  LV     VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  testlv testvg -wi-a----- 7.00g                                                    
[root@centos8 data]# lvs
  LV     VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  testlv testvg -wi-a----- 7.00g                                                    
[root@centos8 data]# df
Filesystem     1K-blocks    Used Available Use% Mounted on
devtmpfs          970016       0    970016   0% /dev
tmpfs             998404       0    998404   0% /dev/shm
tmpfs             998404    9692    988712   1% /run
tmpfs             998404       0    998404   0% /sys/fs/cgroup
/dev/nvme0n1p1 104806400 5418152  99388248   6% /
/dev/nvme0n1p2  52403200  398452  52004748   1% /data
/dev/nvme0n1p5    999320  193944    736564  21% /boot
tmpfs             199680      24    199656   1% /run/user/0
[root@centos8 data]# mount -a
[root@centos8 data]# df
Filesystem     1K-blocks    Used Available Use% Mounted on
devtmpfs          970016       0    970016   0% /dev
tmpfs             998404       0    998404   0% /dev/shm
tmpfs             998404    9692    988712   1% /run
tmpfs             998404       0    998404   0% /sys/fs/cgroup
/dev/nvme0n1p1 104806400 5418152  99388248   6% /
/dev/nvme0n1p2  52403200  398452  52004748   1% /data
/dev/nvme0n1p5    999320  193944    736564  21% /boot
tmpfs             199680      24    199656   1% /run/user/0
[root@centos8 data]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        948M     0  948M   0% /dev
tmpfs           976M     0  976M   0% /dev/shm
tmpfs           976M  9.5M  966M   1% /run
tmpfs           976M     0  976M   0% /sys/fs/cgroup
/dev/nvme0n1p1  100G  5.2G   95G   6% /
/dev/nvme0n1p2   50G  390M   50G   1% /data
/dev/nvme0n1p5  976M  190M  720M  21% /boot
tmpfs           195M   24K  195M   1% /run/user/0

[root@centos8 data]# lvreduce -L 3G /dev/testvg/testlv
  WARNING: Reducing active logical volume to 3.00 GiB.
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce testvg/testlv? [y/n]: y
  Size of logical volume testvg/testlv changed from 7.00 GiB (448 extents) to 3.00 GiB (192 extents).
  Logical volume testvg/testlv successfully resized.
[root@centos8 data]# mount -a
[root@centos8 data]# lvs
  LV     VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  testlv testvg -wi-a----- 3.00g 

6. 对testlv创建快照，并尝试基于快照备份数据，验正快照的功能

[root@centos8 ~]# lvcreate -l 64 -s -n testlv-snapshot /dev/testvg/testlv
  Logical volume "testlv-snapshot" created.
[root@centos8 ~]# lvs
  LV              VG     Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  testlv          testvg owi-aos--- 3.00g                                                    
  testlv-snapshot testvg swi-a-s--- 1.00g      testlv 0.01                                   
[root@centos8 ~]# mkdir -p /mnt/snap 
[root@centos8 testvg]# mount /dev/testvg/testlv-snapshot /mnt/snap
[root@centos8 ~]#rm -rf /users/archlinux/pam.d
[root@centos8 ~]# umount /dev/testvg/testlv-snapshot
[root@centos8 ~]# umount /dev/testvg/testlv
[root@centos8 ~]# lvconvert --merge /dev/testvg/testlv-snapshot
  Merging of volume testvg/testlv-snapshot started.
  testvg/testlv: Merged: 90.88%
  testvg/testlv: Merged: 100.00%
[root@centos8 ~]#ll -d /users/archlinux/pam.d/
drwxr-xr-x. 2 archlinux archlinux 4096 6 Jul  3 18:13 /users/archlinux/pam.d/

7. 创建10G的RAID1，要求CHUNK为128K，文件系统为ext4，有一个空闲盘，开机可自动挂载至/backup目录

[root@centos8 ~]# mdadm -C /dev/md0 -a yes -l 1 -n 2 -x 1 -c 128 /dev/nvme0n2 /dev/nvme0n3
[root@centos8 ~]# mkfs.ext4 /dev/md0
[root@centos8 ~]#vim /etc/fstab
/dev/md0   /backup    ext4    defaults   0    0

8. 创建一个可用空间为10G的RAID10设备，要求CHUNK为256K，文件系统为ext4，开机可自动挂载至/mydata目录

[root@centos8 ~]# ll /dev/nvme*
crw------- 1 root root 244, 0 Jul  3 20:15 /dev/nvme0
brw-rw---- 1 root disk 259, 0 Jul  3 20:15 /dev/nvme0n1
brw-rw---- 1 root disk 259, 1 Jul  3 20:15 /dev/nvme0n1p1
brw-rw---- 1 root disk 259, 2 Jul  3 20:15 /dev/nvme0n1p2
brw-rw---- 1 root disk 259, 3 Jul  3 20:15 /dev/nvme0n1p3
brw-rw---- 1 root disk 259, 4 Jul  3 20:15 /dev/nvme0n1p4
brw-rw---- 1 root disk 259, 5 Jul  3 20:15 /dev/nvme0n1p5
brw-rw---- 1 root disk 259, 6 Jul  3 20:15 /dev/nvme0n2
brw-rw---- 1 root disk 259, 7 Jul  3 20:15 /dev/nvme0n3
brw-rw---- 1 root disk 259, 8 Jul  3 20:15 /dev/nvme0n4
brw-rw---- 1 root disk 259, 9 Jul  3 20:15 /dev/nvme0n5
[root@centos8 ~]# mdadm -C /dev/md1 -a yes -l 10 -n4 -c 256K /dev/nvme0n{2,3,4,5} 
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md1 started.
[root@centos8 ~]# mdadm -D /dev/md1
/dev/md1:
           Version : 1.2
     Creation Time : Sun Jul  3 20:17:41 2022
        Raid Level : raid10
        Array Size : 20953088 (19.98 GiB 21.46 GB)
     Used Dev Size : 10476544 (9.99 GiB 10.73 GB)
      Raid Devices : 4
     Total Devices : 4
       Persistence : Superblock is persistent

       Update Time : Sun Jul  3 20:19:06 2022
             State : clean, resyncing 
    Active Devices : 4
   Working Devices : 4
    Failed Devices : 0
     Spare Devices : 0

            Layout : near=2
        Chunk Size : 256K

Consistency Policy : resync

     Resync Status : 82% complete

              Name : centos8.zhang.org:1  (local to host centos8.zhang.org)
              UUID : 5f349416:9f5df39f:dbce464e:13485475
            Events : 13

    Number   Major   Minor   RaidDevice State
       0     259        6        0      active sync set-A   /dev/nvme0n2
       1     259        7        1      active sync set-B   /dev/nvme0n3
       2     259        8        2      active sync set-A   /dev/nvme0n4
       3     259        9        3      active sync set-B   /dev/nvme0n5
[root@centos8 ~]# mkfs.ext4 /dev/md1
mke2fs 1.45.6 (20-Mar-2020)
Creating filesystem with 5238272 4k blocks and 1310720 inodes
Filesystem UUID: 681578dc-b3eb-42d9-829a-383d2f2e5f9a
Superblock backups stored on blocks: 
    32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
    4096000

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
[root@centos8 ~]# mkdir /mydata
[root@centos8 ~]# vim /etc/fstab
[root@centos8 ~]# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Sat Jun 25 06:16:01 2022
#
# Accessible filesystems, by reference, are maintained under '/dev/disk/'.
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info.
#
# After editing this file, run 'systemctl daemon-reload' to update systemd
# units generated from this file.
#
UUID=ddca8445-2ae2-433f-8e7e-e336d725d975 /                       xfs     defaults        0 0
UUID=59b71875-aa14-4840-9e31-fbc8bac5f783 /boot                   ext4    defaults        1 2
UUID=983eef86-2784-448d-821d-62a4682e6196 /data                   xfs     defaults        0 0
UUID=3b11b9c7-e4e6-4745-9f32-1a4263e79903 none                    swap    defaults        0 0
/dev/md1                                 /mydata                 ext4    defaults        0 0 
[root@centos8 ~]# mount -a
[root@centos8 ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        948M     0  948M   0% /dev
tmpfs           976M     0  976M   0% /dev/shm
tmpfs           976M  9.4M  966M   1% /run
tmpfs           976M     0  976M   0% /sys/fs/cgroup
/dev/nvme0n1p1  100G  5.2G   95G   6% /
/dev/nvme0n1p2   50G  390M   50G   1% /data
/dev/nvme0n1p5  976M  190M  720M  21% /boot
tmpfs           195M   12K  195M   1% /run/user/42
tmpfs           195M     0  195M   0% /run/user/0
/dev/md1         20G   45M   19G   1% /mydata

 

9. 静态配置网卡IP，centos/ubuntu实现

1）centos

[root@centos8 network-scripts]# vim ifcfg-ens160
[root@centos8 network-scripts]# cat ifcfg-ens160
BOOTPROTO=static
IPADDR=10.0.0.150
PREFIX=24
GETWAY=10.0.0.2
DNS1=10.0.0.2
DNS2=180.76.76.76
NAME=ens160
DEVICE=ens160
ONBOOT=yes

2）Ubuntu

root@ubuntu18:/etc/netplan# cat eth0.yaml 
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    eth0:
      addresses: [10.0.0.151/24]
      gateway4: 10.0.0.2

 

10. 图文并茂解释TCP/IP 3次握手4次断开

三次握手：

1、第一次握手：客户端给服务器发送一个SYN报文。

2、第二次握手：服务器收到 SYN 报文之后，会应答一个 SYN+ACK 报文。

3、第三次握手：客户端收到 SYN+ACK 报文之后，会回应一个 ACK 报文。

4、服务器收到 ACK 报文之后，三次握手建立完成。

 

四次挥手：

1：客户端进程发出断开连接指令，这将导致客户端的TCP程序创建一个特殊的TCP报文段，发送到服务器。这个报文段的FIN字段被置为1，表示这是一条断开连接的报文；

2：服务器接收到客户端发来的断开连接报文，向客户端回送这个报文的确认报文（ACK字段为1），告诉服务器已经接收到FIN报文，并允许断开连接；

3：服务器发送完确认报文后，服务器的TCP程序创建一条自己的断开连接报文，此报文的FIN字段被置为1，然后发往客户端；

4：客户端接收到服务器发来的FIN报文段，则产生一条确认报文（ACK为1），发送给服务器，告知服务器已经接收到了它的断开报文。服务器接收到这条ACK报文段后，释放TCP连接相关的资源（缓存和变量），而客户端等待一段时间后（半分钟、一分钟或两分钟），也释放处于客户端的缓存和变量；

 

11. 网卡绑定bond0的实现

1）添加网卡

[root@centos8 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:4b:2f:c7 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.150/24 brd 10.0.0.255 scope global dynamic noprefixroute ens160
       valid_lft 1783sec preferred_lft 1783sec
    inet6 fe80::20c:29ff:fe4b:2fc7/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:5e:de:71 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global noprefixroute virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
    link/ether 52:54:00:5e:de:71 brd ff:ff:ff:ff:ff:ff
5: ens224: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:4b:2f:d1 brd ff:ff:ff:ff:ff:ff

2）创建bond0

root@centos8 ~]# nmcli connection add con-name mybond0 ifname bond0 type bond mode active-backup ipv4.method manual ipv4.addresses 10.0.0.100/24
Connection 'mybond0' (72eb289b-ca00-44c6-a989-40a245afea63) successfully added.
[root@centos8 ~]# cd /etc/sysconfig/network-scripts
[root@centos8 network-scripts]# ls
ifcfg-ens160  ifcfg-mybond0
[root@centos8 network-scripts]# cat ifcfg-mybond0
BONDING_OPTS=mode=active-backup
TYPE=Bond
BONDING_MASTER=yes
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
IPADDR=10.0.0.100
PREFIX=24
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=mybond0
UUID=72eb289b-ca00-44c6-a989-40a245afea63
DEVICE=bond0
ONBOOT=yes

3）网卡添加到bond0中

[root@centos8 network-scripts]# nmcli con add type bond-slave ifname ens160 master bond0
Connection 'bond-slave-ens160' (606b0ff4-6b58-4767-b605-2ac1d9bb1c61) successfully added.
[root@centos8 network-scripts]# nmcli con add type bond-slave ifname ens224 master bond0
Connection 'bond-slave-ens224' (f02329a9-a2e8-4381-8334-f831c84a17ec) successfully added.
root@centos8 network-scripts]# nmcli connection
NAME               UUID                                  TYPE      DEVICE 
ens160             6105387e-245b-434c-ae2d-188e8f6086e7  ethernet  ens160 
mybond0            72eb289b-ca00-44c6-a989-40a245afea63  bond      bond0  
virbr0             db0a8536-2dc9-48fb-8542-fe6ba80331fd  bridge    virbr0 
bond-slave-ens224  f02329a9-a2e8-4381-8334-f831c84a17ec  ethernet  ens224 
bond-slave-ens160  606b0ff4-6b58-4767-b605-2ac1d9bb1c61  ethernet  --     

12. 实现免密登陆脚本, expect登陆远程主机，将生成的密钥写入到目标主机, expect测试远程登陆。
1）通过shift读取脚本参数
2）通过select来选择功能.例如功能有
- 安装mysql
- 安装apache
- 免密钥登陆主机
当前我们只实现免密钥登陆主机
3）通过函数封装每个功能
4）将免密钥登陆的过程可以重复进行, while 循环实现重复，需要有退出过程。当用户输入exit时，退出免密钥功能。
5）支持输入一批主机免密钥，使用数组 实现

 

#!/bin/bash
ssh() {
        while true;do
                read -p "Enter your ip and password" ip password
                        if [ "$ip" = "exit" ];then
                                exit
                        fi
expect << EOF
set timeout 15
spawn ssh-keygen -t rsa
expect {
        "/root/.ssh/id_rsa)"{ send "\r";exp_continue}
        "(y/n)?"{ send "y\n";exp_continue}
        "passphrase):"{ send "\r";exp_continue}
        "again:"{ send "\r";exp_continue}
}
spawn ssh-copy-id root@$ip
expect {
        "yes/no"{ send "yes\n";exp_continue }
        "password"{ send "$password\n"}
 }
expect eof
EOF
done
 }


PS3="Please select a function(1-5)"
select MENU in 安装sql 安装apache 免密钥登录主机 输入一批主机免密钥 退出;do
case $REPLY in
1)
        echo "安装sql";;
2)
        echo "安装apache";;
3)
        ssh;;
4)
        echo "输入一批主机免密钥";;
5)
        echo "exit"
        break;;
"week3.sh" 43L, 774C