第七週練習
阿新 • • 發佈：2021-01-21
一、破壞mbr表並修復
1.先備份MBR分割槽表
[[email protected] ~]# dd if=/dev/sda of=/data/dpt.img bs=1 count=64 skip=446
64+0 records in
64+0 records out
64 bytes copied, 0.0013962 s, 45.8 kB/s
[[email protected] ~]# scp /data/dpt.img 10.0.0.17:/data/
[[email protected] data]# du -h dpt.img
4.0K dpt.img
2.破壞MBR分割槽表，並重啟
[[email protected] ~]# dd if=/dev/zero of=/dev/sda bs=1 count=64 seek=446
[[email protected] ~]#reboot
3.更改啟動項，用光碟啟動，選擇troubleshooting，進入rescue a centos linux，選擇專案3 skip to shell.
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4.配置網路並修復,最後更改啟動項。
sh-4.4#ifconfig ens160 10.0.0.18/24
sh-4.4#scp 10.0.0.17:/data/dpt.img .
sh-4.4#dd if=dpt.img of=/dev/sda bs=1 seek=446
sh-4.4#exit
sh-4.4#reboot
二、總結RAID的各個級別及其組合方式和效能的不同。
RAID: Redundant Arrays of Inexpensive（Independent） Disks 廉價（獨立）磁碟冗餘陣列
由多塊磁碟合成一個陣列來提供更好的效能，如提高磁碟的並行讀寫能力，磁碟的耐用性和冗餘性等。
RAID的級別有：raid0、raid1、raid4、raid5、raid6、raid10、raid01、raid50等
RAID0： 以 chunk 單位,讀寫資料，讀、寫效能提升，可用空間：N*min(S1,S2,...)，沒有容錯能力，最少磁碟數：2, 2+
RAID1：讀效能提升、寫效能略有下降，可用空間：1*min(S1,S2,...)，有容錯能力，最少磁碟數：2, 2N
RAID4：多塊資料盤異或運算值存於專用校驗盤，磁碟利用率 (N-1)/N，有冗餘能力，至少3塊磁碟盤才可以實現
RAID5：讀、寫效能提升，可用空間：(N-1)*min，有容錯能力：允許最多1塊磁碟損壞，最少磁碟數：3, 3+
RAID6：讀、寫效能提升，可用空間：(N-2)*min，有容錯能力：允許最多2塊磁碟損壞，最少磁碟數：4, 4+
RAID10：讀、寫效能提升，可用空間：N*min(S1,S2,...)/2，有容錯能力：每組映象最多隻能壞一塊，最少磁碟數：4, 4+
RAID01：多塊磁碟先實現RAID0,再組合成RAID1
RAID50：多塊磁碟先實現RAID5,再組合成RAID0
三、建立一個2G的檔案系統，塊大小為2048byte，預留1%可用空間,檔案系統 ext4，卷標為TEST，要求此分割槽開機後自動掛載至/test目錄，且預設有acl掛載選項
1、先新增一塊20G的硬碟
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#掃描新增加的20G硬碟
[[email protected] ~]# echo "---" > /sys/class/scsi_host/host16/scan
[[email protected] ~]# cat /proc/partitions
major minor #blocks name
8 0 209715200 sda
8 1 1048576 sda1
8 2 104857600 sda2
8 3 4194304 sda3
8 4 1 sda4
8 5 52428800 sda5
8 16 20971520 sdb
11 0 8038400 sr0
[[email protected] ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 200G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 100G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 50G 0 part /data
sdb 8:16 0 20G 0 disk
sr0 11:0 1 7.7G 0 rom
#檢視硬碟資訊
[[email protected] ~]# fdisk -l
Disk /dev/sda: 200 GiB, 214748364800 bytes, 419430400 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xce9920ed
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 2099199 2097152 1G 83 Linux
/dev/sda2 2099200 211814399 209715200 100G 83 Linux
/dev/sda3 211814400 220203007 8388608 4G 82 Linux swap / Solaris
/dev/sda4 220203008 419430399 199227392 95G 5 Extended
/dev/sda5 220205056 325062655 104857600 50G 83 Linux
Disk /dev/sdb: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
2、#將sdb作為操作目標，在sdb磁碟上建立大小為2G的分割槽
#將sdb作為操作目標，在sdb磁碟上建立大小為2G的分割槽
[[email protected] ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.32.1).
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.
Created a new DOS disklabel with disk identifier 0x40d160c9.
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1):
Last sector, +sectors or +size{K,M,G,T,P} (2048-41943039, default 41943039): +2G
Created a new partition 1 of type 'Linux' and of size 2 GiB.
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
Command (m for help): p
Disk /dev/sdb: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x40d160c9
#檢視增加的2G裝置
[[email protected] ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 200G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 100G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 50G 0 part /data
sdb 8:16 0 20G 0 disk
└─sdb1 8:17 0 2G 0 part
sr0 11:0 1 7.7G 0 rom
3、設定格式為ext4,塊大小2048，卷標為TEST
#格式為ext4,塊大小2048，卷標為TEST
[[email protected] ~]# mkfs.ext4 -b 2048 -m 1 -L TEST /dev/sdb1
mke2fs 1.45.4 (23-Sep-2019)
/dev/sdb1 contains a ext4 file system
created on Wed Jan 20 17:43:33 2021
Proceed anyway? (y,N) Y
Creating filesystem with 1048576 2k blocks and 131072 inodes
Filesystem UUID: b20fb569-49b6-4cf5-9a27-8461ca7ee6c0
Superblock backups stored on blocks:
16384, 49152, 81920, 114688, 147456, 409600, 442368, 802816
Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
[[email protected] ~]# blkid
/dev/sdb1: LABEL="TEST" UUID="b20fb569-49b6-4cf5-9a27-8461ca7ee6c0" TYPE="ext4" PARTUUID="40d160c9-01"
/dev/sda1: UUID="e4ed5ac2-1b02-4cc3-8fd1-ebd299d321b8" TYPE="ext4" PARTUUID="ce9920ed-01"
/dev/sda2: UUID="812abf4b-5d32-4380-a980-a3809d13fffe" TYPE="xfs" PARTUUID="ce9920ed-02"
/dev/sda3: UUID="ccc25742-8377-4ae6-9f90-3f4ec73f37f2" TYPE="swap" PARTUUID="ce9920ed-03"
/dev/sda5: UUID="b5bf8c09-2c50-483d-8ecd-0be7222b9cb3" TYPE="xfs" PARTUUID="ce9920ed-05"
/dev/sr0: UUID="2020-06-08-22-08-25-00" LABEL="CentOS-8-2-2004-x86_64-dvd" TYPE="iso9660" PTUUID="545ce9a4" PTTYPE="dos"
4、設定掛載點，並開機自動掛載到/test,預設選項acl
#設定掛載點，並開機自動掛載到/test,預設選項acl
[[email protected] ~]# mkdir /test
[[email protected] ~]# echo "/dev/sdb1 /test ext4 acl 0 0 " >> /etc/fstab
[[email protected] ~]# mount -a
[[email protected] ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 964M 0 964M 0% /dev
tmpfs 981M 0 981M 0% /dev/shm
tmpfs 981M 8.7M 972M 1% /run
tmpfs 981M 0 981M 0% /sys/fs/cgroup
/dev/sda2 100G 2.5G 98G 3% /
/dev/sda5 50G 778M 50G 2% /data
/dev/sda1 976M 104M 806M 12% /boot
tmpfs 197M 0 197M 0% /run/user/0
/dev/sdb1 2.0G 9.1M 2.0G 1% /test
[[email protected] ~]# cat /etc/fstab
UUID=812abf4b-5d32-4380-a980-a3809d13fffe / xfs defaults 0 0
UUID=e4ed5ac2-1b02-4cc3-8fd1-ebd299d321b8 /boot ext4 defaults 1 2
UUID=b5bf8c09-2c50-483d-8ecd-0be7222b9cb3 /data xfs defaults 0 0
UUID=ccc25742-8377-4ae6-9f90-3f4ec73f37f2 swap swap defaults 0 0
/dev/sdb1 /test ext4 acl 0 0
#重啟測試
WARNING! The remote SSH server rejected X11 forwarding request.
Last login: Wed Jan 20 17:22:26 2021 from 192.168.2.102
[[email protected] ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 200G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 100G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 50G 0 part /data
sdb 8:16 0 20G 0 disk
└─sdb1 8:17 0 2G 0 part /test
sr0 11:0 1 7.7G 0 rom
四、建立一個至少有兩個PV組成的大小為20G的名為testvg的VG;要求PE大小 為16MB, 而後在卷組中建立大小為5G的邏輯卷testlv;掛載至/users目錄
1、先新增一塊20G的硬碟,sdc
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[[email protected] ~]# echo "- - -" > /sys/class/scsi_host/host32/scan
[[email protected] ~]# cat /proc/partitions
major minor #blocks name
8 16 20971520 sdb
8 17 2097152 sdb1
8 0 209715200 sda
8 1 1048576 sda1
8 2 104857600 sda2
8 3 4194304 sda3
8 4 1 sda4
8 5 52428800 sda5
11 0 8038400 sr0
8 32 20971520 sdc
[[email protected] ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 200G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 100G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 50G 0 part /data
sdb 8:16 0 20G 0 disk
└─sdb1 8:17 0 2G 0 part /test
sdc 8:32 0 20G 0 disk
sr0 11:0 1 7.7G 0 rom
2、規劃使用sdb和sdc兩塊磁碟來操作，分別取兩個10G大小的空間。sdb2、sdc1
[[email protected] ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.32.1).
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 (1 primary, 0 extended, 3 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (2-4, default 2):
First sector (4196352-41943039, default 4196352):
Last sector, +sectors or +size{K,M,G,T,P} (4196352-41943039, default 41943039): +10G
Created a new partition 2 of type 'Linux' and of size 10 GiB.
Command (m for help): p
Disk /dev/sdb: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x40d160c9
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 4196351 4194304 2G 83 Linux
/dev/sdb2 4196352 25167871 20971520 10G 83 Linux
Command (m for help): w
The partition table has been altered.
Syncing disks.
[[email protected] ~]# fdisk /dev/sdc
Welcome to fdisk (util-linux 2.32.1).
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.
Created a new DOS disklabel with disk identifier 0x433afee5.
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (1-4, default 1):
First sector (2048-41943039, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-41943039, default 41943039): +10G
Created a new partition 1 of type 'Linux' and of size 10 GiB.
Command (m for help): p
Disk /dev/sdc: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x433afee5
Device Boot Start End Sectors Size Id Type
/dev/sdc1 2048 20973567 20971520 10G 83 Linux
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
[[email protected] ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 200G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 100G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 50G 0 part /data
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 2G 0 part /test
└─sdb2 8:18 0 10G 0 part
sdc 8:32 0 20G 0 disk
└─sdc1 8:33 0 10G 0 part
sr0 11:0 1 7.7G 0 rom
3、建立PV,並檢視建立的PV
[[email protected] ~]#yum install lvm2 -y
[[email protected] ~]# pvcreate /dev/sdb
sdb sdb1 sdb2
[[email protected] ~]# pvcreate /dev/sdb
sdb sdb1 sdb2
[[email protected] ~]# pvcreate /dev/sdb2
Physical volume "/dev/sdb2" successfully created.
[[email protected] ~]# pvcreate /dev/sdc1
Physical volume "/dev/sdc1" successfully created.
[[email protected] ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb2 lvm2 --- 10.00g 10.00g
/dev/sdc1 lvm2 --- 10.00g 10.00g
4、建立名為testvg的VG，PE大小 為16MB，
#建立VG
[[email protected] ~]# vgcreate testvg -s 16M /dev/sdb2 /dev/sdc1
Volume group "testvg" successfully created
#檢視VG， PE Size 16.00 MiB
[[email protected] ~]# vgs
VG #PV #LV #SN Attr VSize VFree
testvg 2 0 0 wz--n- <19.97g <19.97g
[[email protected] ~]# vgdisplay testvg
--- 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 <19.97 GiB
PE Size 16.00 MiB #pe大小16M
Total PE 1278
Alloc PE / Size 0 / 0
Free PE / Size 1278 / <19.97 GiB
VG UUID ZJd68K-KSS5-inC2-MAZi-6LQt-203d-hl9UGQ
5、在卷組中建立大小為5G的邏輯卷testlv;掛載至/users目錄
#建立大小為5G的邏輯卷testlv
[email protected] ~]# lvcreate -L 5G -n testvg testvg
Logical volume "testvg" created.
[[email protected] ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
testvg testvg -wi-a----- 5.00g
[[email protected] ~]# lvcreate -L 5G -n testlv testvg
Logical volume "testlv" created.
[[email protected] ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
testlv testvg -wi-a----- 5.00g
testvg testvg -wi-a----- 5.00g
[[email protected] ~]# lvremove /dev/testvg/testvg
Do you really want to remove active logical volume testvg/testvg? [y/n]: y
Logical volume "testvg" successfully removed
[[email protected] ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
testlv testvg -wi-a----- 5.00g
#檢視卷組資訊， LV Size 5.00 GiB
[[email protected] ~]# lvdisplay /dev/testvg/testlv
--- Logical volume ---
LV Path /dev/testvg/testlv
LV Name testlv
VG Name testvg
LV UUID eqfOys-mhxg-3Uce-1KWv-MLax-CoGL-ni9gYG
LV Write Access read/write
LV Creation host, time n51c8, 2021-01-20 21:00:27 +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 253:1
#格式化卷組/dev/testvg/testlv 為ext4格式
[[email protected] ~]# mkfs.ext4 /dev/testvg/testlv
mke2fs 1.45.4 (23-Sep-2019)
Creating filesystem with 1310720 4k blocks and 327680 inodes
Filesystem UUID: c47c3e5e-44cc-4353-a499-69205e01c9b0
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
#建立掛載點/users,並開機自動掛載
[[email protected] ~]#
[[email protected] ~]# mkdir /users
[[email protected] ~]# echo "/dev/testvg/testlv /users ext4 defaults 0 0" >> /etc/fstab
[[email protected] ~]# mount -a
[[email protected] ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 964M 0 964M 0% /dev
tmpfs 981M 8.0K 981M 1% /dev/shm
tmpfs 981M 8.7M 972M 1% /run
tmpfs 981M 0 981M 0% /sys/fs/cgroup
/dev/sda2 100G 2.5G 98G 3% /
/dev/sda5 50G 778M 50G 2% /data
/dev/sdb1 2.0G 9.1M 2.0G 1% /test
/dev/sda1 976M 104M 806M 12% /boot
tmpfs 197M 0 197M 0% /run/user/0
/dev/mapper/testvg-testlv 4.9G 20M 4.6G 1% /users
[[email protected] ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 200G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 100G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 50G 0 part /data
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 2G 0 part /test
└─sdb2 8:18 0 10G 0 part
sdc 8:32 0 20G 0 disk
└─sdc1 8:33 0 10G 0 part
└─testvg-testlv 253:1 0 5G 0 lvm /users
sr0 11:0 1 7.7G 0 rom
#
[[email protected] ~]# cat /etc/fstab | grep -v "#"
UUID=812abf4b-5d32-4380-a980-a3809d13fffe / xfs defaults 0 0
UUID=e4ed5ac2-1b02-4cc3-8fd1-ebd299d321b8 /boot ext4 defaults 1 2
UUID=b5bf8c09-2c50-483d-8ecd-0be7222b9cb3 /data xfs defaults 0 0
UUID=ccc25742-8377-4ae6-9f90-3f4ec73f37f2 swap swap defaults 0 0
/dev/sdb1 /test ext4 acl 0 0
/dev/testvg/testlv /users ext4 defaults 0 0