linux之一把梭

 学到哪梭到哪

一、两台Linux主机ssh免密登录配置

[root@localhost ~]# ssh-keygen

[root@localhost ~]# ssh-copy-id 对端IP

 

 

二、两台linux在一台当中copy某个安装包（一台有yum源，另外一台没有yum源）

[root@localhost ~]# yumdownloader --resolve --destdir /root perf (resolve解决包的依赖问题，destdir指定下载路径)

[root@localhost ~]# scp /root/perf-4.19.90-23.8.v2101.ky10.aarch64.rpm root@10.25.192.220:/root

 

三、linux配置本地yum源

** 注意，虽然能一把梭，但是梭之前如果是现网系统，请务必确认以下内容是否有回显

ls /mnt/iso

若回显为 ls: cannot access '/mnt/iso': No such file or directory 是正常的，若回显为其他则别瞎β梭

以下为一把梭步骤：

1. 挂载iso文件
2. 以下内容一把梭

mkdir /mnt/iso

mount /dev/sr0 /mnt/iso

cd /etc/yum.repos.d/

mkdir back && mv * back

touch cdrom.repo

echo "[cdrom]" >> cdrom.repo

echo "name = cdrom" >> cdrom.repo

echo "baseurl = file:///mnt/iso" >> cdrom.repo

echo "enable = 1" >> cdrom.repo

echo "gpgcheck = 0" >> cdrom.repo

yum makecache

1. 环境清理一把梭

cd /etc/yum.repos.d/

rm -f cdrom.repo

mv back/* .

rmdir back

yum clean all

cd

umount /mnt/iso

rmdir /mnt/iso

 

四、rpm安装软件包

如果用rpm -ivh安装软件包提示no key可能是缺少依赖包此时可以采用一下命令强制安装：

rpm -ivh “软件包” --force --nodeps

 

 

五、LVM

环境新添加一块sdc10G盘用来做玩LVM

[root@localhost ~]# lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT

sda 8:0 0 50G 0 disk

├─sda1 8:1 0 1G 0 part /boot

└─sda2 8:2 0 49G 0 part

├─centos-root 253:0 0 47G 0 lvm /

└─centos-swap 253:1 0 2G 0 lvm [SWAP]

sdb 8:16 0 10G 0 disk

├─sdb1 8:17 0 3G 0 part

│ └─zzvg-zzlv 253:2 0 2G 0 lvm

├─sdb2 8:18 0 3G 0 part

└─sdb3 8:19 0 2G 0 part

sdc 8:32 0 10G 0 disk

sr0 11:0 1 4.4G 0 rom

 

LVM从下到上的架构依次是PV，VG，LV，其中VG是由多个PE构成，LVM的优点是弹性伸缩空间针对的是添加，减少PE。

PV（Physical Volume, PV, 实体卷轴）

VG（Volume Group, VG, 卷轴群组）

PE（Physical Extent, PE, 实体范围区块）

LV（Logical Volume, LV, 逻辑卷轴）

 

一把梭
1、分区
可以选择用fdisk进行分区，也可以选择用gdisk进行分区。
如果用gdisk进行分区可以修改分区code值为8e00，8e00代表LVM linux，没啥用就是给管理员看的。
此处采用fdisk进行分区。
[root@localhost ~]# fdisk /dev/sdc
Welcome to fdisk (util-linux 2.23.2).

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 0x921e8d97.

Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): +2G
Partition 1 of type Linux and of size 2 GiB is set

Command (m for help): n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p): p
Partition number (2-4, default 2): 2
First sector (4196352-20971519, default 4196352):
Using default value 4196352
Last sector, +sectors or +size{K,M,G} (4196352-20971519, default 20971519): +2G
Partition 2 of type Linux and of size 2 GiB is set

Command (m for help): p

Disk /dev/sdc: 10.7 GB, 10737418240 bytes, 20971520 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
Disk label type: dos
Disk identifier: 0x921e8d97

Device Boot Start End Blocks Id System
/dev/sdc1 2048 4196351 2097152 83 Linux
/dev/sdc2 4196352 8390655 2097152 83 Linux

Command (m for help):

 

[root@localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 49G 0 part
├─centos-root 253:0 0 47G 0 lvm /
└─centos-swap 253:1 0 2G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
├─sdb1 8:17 0 3G 0 part
│ └─zzvg-zzlv 253:2 0 2G 0 lvm /root/zzlvm
├─sdb2 8:18 0 3G 0 part
└─sdb3 8:19 0 2G 0 part
sdc 8:32 0 10G 0 disk
├─sdc1 8:33 0 2G 0 part
└─sdc2 8:34 0 2G 0 part
sr0 11:0 1 4.4G 0 rom /mnt/cdrom

 

2、创建PV
创建PV将sdc1，sdc2加入到PV里。
[root@localhost ~]# pvcreate /dev/sdc{1,2}
Physical volume "/dev/sdc1" successfully created.
Physical volume "/dev/sdc2" successfully created.

[root@localhost ~]# pvscan
PV /dev/sdb1 VG zzvg lvm2 [2.98 GiB / 992.00 MiB free]
PV /dev/sdb2 VG zzvg lvm2 [2.98 GiB / 2.98 GiB free]
PV /dev/sdb3 VG zzvg lvm2 [1.98 GiB / 1.98 GiB free]
PV /dev/sda2 VG centos lvm2 [<49.00 GiB / 4.00 MiB free]
PV /dev/sdc1 lvm2 [2.00 GiB]
PV /dev/sdc2 lvm2 [2.00 GiB]
Total: 6 [<60.95 GiB] / in use: 4 [<56.95 GiB] / in no VG: 2 [4.00 GiB]

[root@localhost ~]# pvdisplay /dev/sdc1
"/dev/sdc1" is a new physical volume of "2.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdc1
VG Name
PV Size 2.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID A9L0s1-kcS3-hZgB-nhl5-CLm4-udWp-O9vGm3


3、创建VG
将sdc1，sdc2创建一个成为一个VG指定名称为vbirdvg，指定PE为4M
[root@localhost ~]# vgcreate -s 4M vbirdvg /dev/sdc{1,2}
Volume group "vbirdvg" successfully created

[root@localhost ~]# vgscan
Reading volume groups from cache.
Found volume group "vbirdvg" using metadata type lvm2
Found volume group "zzvg" using metadata type lvm2
Found volume group "centos" using metadata type lvm2

[root@localhost ~]# vgdisplay vbirdvg
--- Volume group ---
VG Name vbirdvg
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 3.99 GiB
PE Size 4.00 MiB
Total PE 1022
Alloc PE / Size 0 / 0
Free PE / Size 1022 / 3.99 GiB
VG UUID wKyd2V-Cr8K-xfV2-5wE1-SUj1-9QBu-Jackx3

VG扩容将sdc3分区也加入到vbirdvg中
[root@localhost ~]# vgextend vbirdvg /dev/sdc3
VG缩容将sdc3分区从vbirdvg中移除
[root@localhost ~]# vgreduce vbirdvg /dev/sdc3

4、创建LV
从VG中分出2G用来创建一个vbirdlv
[root@localhost ~]# lvcreate -L 2G -n vbirdlv vbirdvg
Logical volume "vbirdlv" created.

[root@localhost ~]# lvscan
ACTIVE '/dev/vbirdvg/vbirdlv' [2.00 GiB] inherit
ACTIVE '/dev/zzvg/zzlv' [<2.02 GiB] inherit
ACTIVE '/dev/centos/swap' [2.00 GiB] inherit
ACTIVE '/dev/centos/root' [46.99 GiB] inherit

[root@localhost ~]# lvdisplay /dev/vbirdvg/vbirdlv
--- Logical volume ---
LV Path /dev/vbirdvg/vbirdlv
LV Name vbirdlv
VG Name vbirdvg
LV UUID nX255d-90Yd-b3Rc-Eiiq-VV0L-tR9l-PnzwqT
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2023-06-08 11:20:27 -0400
LV Status available
# open 0
LV Size 2.00 GiB
Current LE 512
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:3

5、分区格式化LV，挂载
分区格式化文件系统可以用xfs或者ext4，如果采用xfs进行格式化后续对于分区空间只能扩容，想要缩容只能从新格式化。才用ext4进行格式化则可以动态调节分区大小。
[root@localhost ~]# mkfs.ext4 /dev/vbirdvg/vbirdlv
[root@localhost ~]# mount /dev/vbirdvg/vbirdlv /root/vbirdlvm/
[root@localhost ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 475M 0 475M 0% /dev
tmpfs tmpfs 487M 0 487M 0% /dev/shm
tmpfs tmpfs 487M 7.7M 479M 2% /run
tmpfs tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 47G 1.5G 46G 4% /
/dev/sr0 iso9660 4.4G 4.4G 0 100% /mnt/cdrom
/dev/sda1 xfs 1014M 138M 877M 14% /boot
tmpfs tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/zzvg-zzlv ext4 2.0G 3.1M 1.9G 1% /root/zzlvm
/dev/mapper/vbirdvg-vbirdlv ext4 2.0G 6.0M 1.8G 1% /root/vbirdlvm

6、扩容
此lv扩容1G
[root@localhost ~]# lvextend -L +1G /dev/vbirdvg/vbirdlv （调整逻辑卷大小）
Size of logical volume vbirdvg/vbirdlv changed from 2.00 GiB (512 extents) to 3.00 GiB (768 extents).
Logical volume vbirdvg/vbirdlv successfully resized.
[root@localhost ~]# lvscan
ACTIVE '/dev/vbirdvg/vbirdlv' [3.00 GiB] inherit
ACTIVE '/dev/zzvg/zzlv' [<2.02 GiB] inherit
ACTIVE '/dev/centos/swap' [2.00 GiB] inherit
ACTIVE '/dev/centos/root' [46.99 GiB] inherit
[root@localhost ~]# df -Th(实际空间还是2G)
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 475M 0 475M 0% /dev
tmpfs tmpfs 487M 0 487M 0% /dev/shm
tmpfs tmpfs 487M 7.7M 479M 2% /run
tmpfs tmpfs 487M 0 487M 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 47G 1.5G 46G 4% /
/dev/sr0 iso9660 4.4G 4.4G 0 100% /mnt/cdrom
/dev/sda1 xfs 1014M 138M 877M 14% /boot
tmpfs tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/zzvg-zzlv ext4 2.0G 3.1M 1.9G 1% /root/zzlvm
/dev/mapper/vbirdvg-vbirdlv ext4 2.0G 6.0M 1.8G 1% /root/vbirdlvm
[root@localhost ~]# resize2fs -p /dev/vbirdvg/vbirdlv（调整逻辑大小于物理大小一致）

7、缩容
先取消挂载
[root@localhost ~]# mount /dev/vbirdvg/vbirdlv /root/vbirdlvm/
必须检查文件系统
[root@localhost ~]# e2fsck -fy /dev/vbirdvg/vbirdlv
缩小文件系统至1G
[root@localhost ~]# resize2fs /dev/vbirdvg/vbirdlv 1G
缩小逻辑卷大小至1G
[root@localhost ~]# lvreduce -L 1G /dev/vbirdvg/vbirdlv 两者对齐
[root@localhost ~]# resize2fs /dev/vbirdvg/vbirdlv