1牍蜂、磁盤lvm管理会宪，完成下面要求妖碉，并寫出詳細(xì)過程：
- 創(chuàng)建一個(gè)至少有兩個(gè)PV組成的大小為20G的名為testvg的VG;要求PE大小 為16MB, 而后在卷組中創(chuàng)建大小為5G的邏輯卷testlv;掛載至/users目錄
格式成LVM分區(qū)：
[root@localhost ~]#fdisk /dev/sdb
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-13054, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-13054, default 13054): +10G
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (1307-13054, default 1307):
Using default value 1307
Last cylinder, +cylinders or +size{K,M,G} (1307-13054, default 13054): +10G
Command (m for help): p
Device Boot Start End Blocks Id System
/dev/sdb1 1 1306 10490413+ 83 Linux
/dev/sdb2 1307 2612 10490445 83 Linux
Command (m for help): t
Partition number (1-4): 1
Hex code (type L to list codes): L
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 41 PPC PReP Boot 85 Linux extended c7 Syrinx
5 Extended 42 SFS 86 NTFS volume set da Non-FS data
6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt
9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access
a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT
1e Hidden W95 FAT1
Hex code (type L to list codes): 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 8e
Changed system type of partition 2 to 8e (Linux LVM)
Command (m for help): p
Device Boot Start End Blocks Id System
/dev/sdb1 1 1306 10490413+ 8e Linux LVM
/dev/sdb2 1307 2612 10490445 8e Linux LVM
Expert command (m for help): w
[root@localhost ~]#partx -a /dev/sdb ：同步硬盤信息
BLKPG: Device or resource busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
準(zhǔn)備好了實(shí)驗(yàn)空間：
[root@localhost ~]#lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.7G 0 rom /media/CentOS_6.10_Final_
sr1 11:1 1 2G 0 rom /media/CentOS_6.10_Final
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 50G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 2G 0 part [SWAP]
sdb 8:16 0 100G 0 disk
├─sdb1 8:17 0 10G 0 part
└─sdb2 8:18 0 10G 0 part
[root@localhost ~]#
創(chuàng)建pv卷：
[root@localhost ~]#pvcreate /dev/sdb{1,2}
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdb2" successfully created
創(chuàng)建vg組：
[root@localhost ~]#vgcreate -s 16M testvg /dev/sdb{1,2} :PE大小為16MB
Volume group "testvg" successfully created
[root@localhost ~]#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 20.00 GiB
PE Size 16.00 MiB
Total PE 1280
Alloc PE / Size 0 / 0
Free PE / Size 1280 / 20.00 GiB
VG UUID BSoTiQ-UdaW-KKxP-PQcC-ddoY-rVn6-UMbUDF
創(chuàng)建lv卷：
[root@localhost ~]#lvcreate -L 5G -n testlv /dev/testvg
Logical volume "testlv" created.
[root@localhost ~]#lvdisplay /dev/testvg/testlv
--- Logical volume ---
LV Path /dev/testvg/testlv
LV Name testlv
VG Name testvg
LV UUID g3C2fF-mZ4O-q6wn-1jaK-t8TY-wfcP-HDkxMr
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2019-05-31 12:14:41 +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 256
Block device 253:0
掛載至/users目錄：
[root@localhost ~]#mkfs.ext4 /dev/testvg/testlv :格式化為ext4文件系統(tǒng)類型
[root@localhost ~]#blkid /dev/testvg/testlv ：查看是否分配了UUID
/dev/testvg/testlv: UUID="6d65db30-9b69-41ed-bbc6-523272c1afc7" TYPE="ext4"
[root@localhost ~]# mkdir users ：創(chuàng)建目錄
[root@localhost ~]# mount /dev/testvg/testlv /users/ ：掛載至/users目錄
[root@localhost ~]#df -h | grep "/users" ：查看分區(qū)情況和大小
/dev/mapper/testvg-testlv 4.8G 10M 4.6G 1% /users
- 擴(kuò)展testlv至7G咆瘟，要求archlinux用戶的文件不能丟失
[root@localhost ~]# useradd archlinux -d /users/archlinux ：創(chuàng)建用戶并指定其家目錄
[root@localhost ~]# su - archlinux ：切換用戶
[archlinux@localhost ~]$ cp -av /etc/pam.d /users/archlinux ：復(fù)制文件
[archlinux@localhost ~]$ ls /users/archlinux/pam.d/ | wc -l ：查看文件個(gè)數(shù)
57
[root@localhost ~]#vgs
VG #PV #LV #SN Attr VSize VFree
testvg 2 1 0 wz--n- 20.00g 15.00g ：還剩15G空間温鸽，足夠使用
[root@localhost ~]#lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
testlv testvg -wi-ao---- 5.00g
[root@localhost ~]#lvextend -L +2G -r /dev/testvg/testlv ：原有5G加2G擴(kuò)充至7G
Size of logical volume testvg/testlv changed from 5.00 GiB (320 extents) to 7.00 GiB (448 extents).
Logical volume testlv successfully resized.
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/testvg-testlv is mounted on /users; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 1
Performing an on-line resize of /dev/mapper/testvg-testlv to 1835008 (4k) blocks.
The filesystem on /dev/mapper/testvg-testlv is now 1835008 blocks long.
[root@localhost ~]#lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
testlv testvg -wi-ao---- 7.00g ：擴(kuò)充成功
[root@localhost ~]#df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 99G 3.6G 90G 4% /
tmpfs 931M 76K 931M 1% /dev/shm
/dev/sda3 50G 52M 47G 1% /app
/dev/sda1 976M 39M 887M 5% /boot
/dev/sr1 2.1G 2.1G 0 100% /media/CentOS_6.10_Final
/dev/sr0 3.8G 3.8G 0 100% /media/CentOS_6.10_Final_
/dev/mapper/testvg-testlv
6.8G 12M 6.5G 1% /users ：原來4.8瓤鼻，現(xiàn)在6.8擴(kuò)充成功
[root@localhost ~]#ls /users/archlinux/pam.d/|wc -l ：查看文件數(shù)有沒有丟失
57
- 收縮testlv至3G秉版，要求archlinux用戶的文件不能丟失
[root@localhost ~]#umount /dev/testvg/testlv ：必須先卸載
[root@localhost ~]#e2fsck -fy /dev/testvg/testlv ：檢查文件系統(tǒng)
e2fsck 1.41.12 (17-May-2010)
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/testvg/testlv: 78/458752 files (0.0% non-contiguous), 64509/1835008 blocks
[root@localhost ~]#resize2fs /dev/testvg/testlv 3G ：設(shè)置文件系統(tǒng)大小
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/testvg/testlv to 786432 (4k) blocks.
The filesystem on /dev/testvg/testlv is now 786432 blocks long.
[root@localhost ~]#lvreduce -L 3G /dev/testvg/testlv ：縮減邏輯卷為3G
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 testlv successfully resized.
[root@localhost ~]#lvs ：查看邏輯卷大小
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
testlv testvg -wi-a----- 3.00g
[root@localhost ~]#mount /dev/testvg/testlv /users ：掛載
[root@localhost ~]#df -h ：查看物理卷為2.9有一點(diǎn)誤差正常
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 99G 3.6G 90G 4% /
tmpfs 931M 76K 931M 1% /dev/shm
/dev/sda3 50G 52M 47G 1% /app
/dev/sda1 976M 39M 887M 5% /boot
/dev/sr1 2.1G 2.1G 0 100% /media/CentOS_6.10_Final
/dev/sr0 3.8G 3.8G 0 100% /media/CentOS_6.10_Final_
/dev/mapper/testvg-testlv
2.9G 7.8M 2.7G 1% /users
[root@localhost ~]#ls /users/archlinux/pam.d/ | wc -l ：查看文件數(shù)是否丟失
57
- 對(duì)testlv創(chuàng)建快照，并嘗試基于快照備份數(shù)據(jù)茬祷，驗(yàn)證快照的功能
[root@localhost ~]#lvcreate -L 1G -s -n testanap -p r /dev/testvg/testlv ：用lvcreate創(chuàng)建快照 -n指定快照名 -s表示為快照 -p r 為只讀屬性 -L 指定快照大小 /dev/testvg/testlv為源邏輯卷
Logical volume "testanap" created.
[root@localhost ~]#lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
testanap testvg sri-a-s--- 1.00g testlv 0.00
testlv testvg owi-aos--- 3.00g
[root@localhost ~]#mkdir /users/testsnap
[root@localhost ~]#mount /dev/testvg/testanap /users/testsnap/
mount: block device /dev/mapper/testvg-testanap is write-protected, mounting read-only
[root@localhost ~]#rm -f /users/archlinux/pam.d/a* ：刪掉一些數(shù)據(jù)
[root@localhost ~]#ls /users/archlinux/pam.d/|wc -l
51
[root@localhost ~]#ls /users/testsnap/archlinux/pam.d/|wc -l ：快照的數(shù)據(jù)
57
[root@localhost ~]#umount /users/testsnap/：先卸載清焕，再用快照還原
[root@localhost ~]#umount /users/
[root@localhost ~]#lvconvert --merge /dev/testvg/testanap ：將快照進(jìn)行還原
Merging of volume testanap started.
testlv: Merged: 100.0%
Merge of snapshot into logical volume testlv has finished.
Logical volume "testanap" successfully removed
[root@localhost ~]#mount /dev/testvg/testlv /users
[root@localhost ~]#ls /users/archlinux/pam.d/|wc -l ：快照還原成功
57
[root@localhost ~]#
2、創(chuàng)建一個(gè)可用空間為1G的RAID1設(shè)備祭犯，文件系統(tǒng)為ext4秸妥，有一個(gè)空閑盤，開機(jī)可自動(dòng)掛載至/backup目錄
[root@localhost ~]#lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.7G 0 rom /media/CentOS_6.10_Final_
sr1 11:1 1 2G 0 rom /media/CentOS_6.10_Final
sdb 8:16 0 100G 0 disk
├─sdb1 8:17 0 10G 0 part
│ └─testvg-testlv (dm-0) 253:0 0 3G 0 lvm
└─sdb2 8:18 0 10G 0 part
sdc 8:32 0 50G 0 disk
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 50G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 2G 0 part [SWAP]
sdd 8:48 0 50G 0 disk
[root@localhost ~]#mdadm -C -a yes /dev/md0 -l 1 -n 2 /dev/sd{c,d} ：創(chuàng)建RAID1mdadm -C 創(chuàng)建 -a yes 初始化設(shè)備 /dev/md0設(shè)備 -l raid級(jí)別 -n 幾個(gè)成員 /dev/sd{c,d}raid成員
mdadm: Note: this array has metadata at the start and
may not be suitable as a boot device. If you plan to
store '/boot' on this device please ensure that
your boot-loader understands md/v1.x metadata, or use
--metadata=0.90
Continue creating array? yes
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
[root@localhost ~]#lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.7G 0 rom /media/CentOS_6.10_Final_
sr1 11:1 1 2G 0 rom /media/CentOS_6.10_Final
sdb 8:16 0 100G 0 disk
├─sdb1 8:17 0 10G 0 part
│ └─testvg-testlv (dm-0) 253:0 0 3G 0 lvm
└─sdb2 8:18 0 10G 0 part
sdc 8:32 0 50G 0 disk
└─md0 9:0 0 50G 0 raid1
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 50G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 2G 0 part [SWAP]
sdd 8:48 0 50G 0 disk
└─md0 9:0 0 50G 0 raid1
[root@localhost ~]#mkfs.ext4 /dev/md0 ：文件系統(tǒng)ext4
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
3276800 inodes, 13099008 blocks
654950 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
400 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
perblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 26 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#vim /etc/fstab ：末行模式:r!blkid /dev/md0 得到UUID
UUID下加一行沃粗，實(shí)現(xiàn)自動(dòng)掛載
UUID="72ee9911-c031-4ee5-a910-1caf1c44caaa" /backup ext4 defaults 0 0
~
"/etc/fstab" 18L, 1089C written
[root@localhost ~]#
3粥惧、簡述TCP鏈接建立和斷開過程
TCP協(xié)議的鏈接特性：
常見狀態(tài)：
LISTEN：監(jiān)聽；
ESTABLISHED：建立的連接最盅；
FIN_WAIT_1：發(fā)送斷開后等待斷開確認(rèn)突雪；
FIN_WAIT_2：收到斷開后確認(rèn)斷開起惕；
SYN_SENT：確認(rèn)收到斷開信號(hào)；
SYN_RECV：確認(rèn)挂签；
建立連接：三次握手疤祭；
tcp建立連接時(shí)，在兩個(gè)方向上要分別建立虛鏈路饵婆，一個(gè)是客戶端發(fā)SYN=1,seq=x，服務(wù)器端收戏售，另一個(gè)是服務(wù)器端發(fā)SYN=1,ACK=1,seq=y,ack=x+1侨核，客戶端收并發(fā)出確認(rèn)信息ACK=1,seq=x+1,ack=y+1；所以第一次握手灌灾，是客戶端發(fā)請(qǐng)求與服務(wù)端通信搓译，第二次是服務(wù)器端響應(yīng)并請(qǐng)求與客戶端通信，第三次是客戶端響應(yīng)锋喜，所以是三次握手建立連接些己；接下來就是建立連接雙方通信；
斷開連接：四次揮手嘿般；
斷開鏈接時(shí)段标，一般是發(fā)起請(qǐng)求的一方即客戶端發(fā)起斷開請(qǐng)求，斷開分為4次炉奴，第一次是客戶端請(qǐng)求斷開發(fā)送FIN=1,seq=u逼庞，第二次服務(wù)端響應(yīng)客戶端并發(fā)出確認(rèn)收到報(bào)文ACK=1,seq=v,ack=u+1，第三次是服務(wù)器傳送中的數(shù)據(jù)全部完成后發(fā)送斷開連接信息FIN=1,ACK=1,seq=w,ack=u+1瞻赶，第四次是客戶端響應(yīng)服務(wù)端ACK=1,seq=u+1赛糟，ack=w+1；因此斷開時(shí)砸逊，第一次是客戶端請(qǐng)求斷開自己的鏈接璧南，并等待對(duì)方響應(yīng)，而第三次是服務(wù)端請(qǐng)求斷開自己的鏈接师逸，并等待對(duì)方響應(yīng)的過程司倚；
4、簡述TCP和UDP的區(qū)別
tcp：面向連接的協(xié)議字旭；通信開始之前对湃，要建立一個(gè)虛鏈路；通信完成后還要拆除連接遗淳；
udp：無連接的協(xié)議拍柒；直接發(fā)送數(shù)據(jù)報(bào)文（不管對(duì)方能不能接收到，竭盡全力的發(fā)）屈暗；
