1.分区工具
fdisk MBR分区表，只有4个主分区，适用于2TB下的分区
gdisk GPT分区表，128个分区，
parted 高级分区工具
```
```shell
[root@oldboyedu ~]# fdisk /dev/sdb
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 0xf35f2768.
Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition #删除分区
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types #显示分区列表信息
m print this menu #菜单
n add a new partition #创建新的分区
o create a new empty DOS partition table
p print the partition table #打印分区表信息
q quit without saving changes #退出
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit #保存并退出
x extra functionality (experts only)
2. Fdisk
```shell
#1. 添加硬盘
#2. 创建分区
fdisk /dev/sdb
#3.格式化，做文件系统
mkfs.xfs /dev/sdb1
#4.创建一个挂载点
mkdir /data
#5.进行挂载
mount /dev/sdb1 /data
#6.永久挂载，开机自启动挂载
/etc/fstab
/dev/sdb1 /data xfs defaults 0 0
mount -a
reboot
```
3. Gdisk
```shell
#1.添加硬盘3TB
#2.gdisk分区，创建分区
下载安装 yum install -y gdisk
Command (? for help): m
b back up GPT data to a file
c change a partition's name
d delete a partition #删除分区
i show detailed information on a partition
l list known partition types #显示分区列表
n add a new partition #创建分区
o create a new empty GUID partition table (GPT)
p print the partition table #打印分区表信息
q quit without saving changes #退出
r recovery and transformation options (experts only)
s sort partitions
t change a partition's type code
v verify disk
w write table to disk and exit #保存退出
x extra functionality (experts only)
? print this menu #菜单
#3.格式化，创建文件系统
[root@oldboyedu ~]# mkfs.xfs /dev/sdc1
#4.创建挂载点
[root@oldboyedu ~]# mkdir /gpt
#5.挂载
[root@oldboyedu ~]# mount /dev/sdc1 /gpt
#6.永久挂载
[root@oldboyedu ~]# tail -1 /etc/fstab
/dev/sdc1 /gpt xfs defaults 0 0
4. 磁盘的挂载方式
mount 挂载磁盘
选项：
-t #指定文件系统
-a #重新加载/etc/fstab文件挂载列表
-o #指定挂载的参数
umount 卸载
选项：
-l #强制卸载
或者退出挂载目录进行卸载。
永久挂载：/etc/fstab 推荐使用UUID进行挂载
#查看UUID的信息
[root@oldboyedu ~]# blkid
/dev/sr0: UUID="2018-11-25-23-54-16-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"
/dev/sdb1: UUID="86f77539-a04d-4448-aa45-e77644b67f71" TYPE="xfs"
/dev/sdc1: UUID="a0c64606-5655-4090-b6cd-464b201f3837" TYPE="xfs" PARTLABEL="Linux filesystem" PARTUUID="ba2761a8-1031-4bff-ad1a-cfa6c37cffab"
/dev/sda1: UUID="e7d2d29d-d679-4f0f-8acb-e86ffbe9b5f9" TYPE="xfs"
/dev/sda2: UUID="7b4436bc-2748-49ba-9ff8-a5923eaf2127" TYPE="swap"
/dev/sda3: UUID="8a332f48-6869-4866-9e8d-698aaaf744df" TYPE="xfs
#临时挂载
[root@oldboyedu ~]# mount UUID="a0c64606-5655-4090-b6cd-464b201f3837" /gpt
#永久挂载
[root@oldboyedu ~]# tail -1 /etc/fstab
UUID="a0c64606-5655-4090-b6cd-464b201f3837" /gpt xfs defaults 0 0
#/etc/fstab文件详解
UUID="a0c64606-5655-4090-b6cd-464b201f3837" /gpt xfs defaults 0 0
第一列：设备名，UUID，网络地址
第二列：挂载点
第三列：文件系统的类型 ext3 ext4 xfs swap
第四列：默认挂载的参数，defaults，
async/sync 是否同步，或者异步，默认的是async
user/nouser 是否让普通用户使用挂载命令，nouser
suid/nosuid suid
exec/noexec 是否有执行文件的权限，exec
auto/noauto 执行mount -a时，此文件系统是否被主动挂载，默认auto
rw/ro 读写，只读， rw
第五列：是否使用dump命令进行备份 0 不备份，1 每天备份 2 不定期的备份
第六列：通过什么方式让fsck检查磁盘， 0 不检查 ， 1 检查，/ 2 其他的分区 ，检查的顺序
5. Swap介绍
**企业案例：java内存不足时，大量占用swap。**
```shell
#1.添加一个1G分区
#2.格式化为swap
[root@oldboyedu ~]# mkswap /dev/sdb5
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 1980 107 1529 9 343 1694
Swap: 2047 0 2047
[root@oldboyedu ~]# swapon /dev/sdb5
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 1980 109 1527 9 343 1692
Swap: 3071 0 3071
[root@oldboyedu ~]# swapon -s
Filename Type Size Used Priority
/dev/sda2 partition 2097148 0 -2
/dev/sdb5 partition 1048572 0 -3
[root@oldboyedu ~]# swapoff /dev/sdb5
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 1980 107 1529 9 343 1693
Swap: 2047 0 2047
[root@oldboyedu ~]# swapoff -a
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 1980 106 1531 9 342 1694
Swap: 0 0 0
[root@oldboyedu ~]# swapon -a
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 1980 107 1530 9 342 1694
Swap: 2047 0 2047
#生成一个大文件
[root@oldboyedu ~]# dd /root/swap_file bs=10M count=100
#格式化该文件为swap文件
[root@oldboyedu ~]# mkswap -f /root/swap_file
Setting up swapspace version 1, size = 1023996 KiB
no label, UUID=6930c391-2924-464b-a126-be1f85b953b6
[root@oldboyedu ~]# file /root/swap_file
/root/swap_file: Linux/i386 swap file (new style), version 1 (4K pages), size 255999 pages, no label, UUID=6930c391-2924-464b-a126-be1f85b953b6
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 1980 107 499 9 1374 1679
Swap: 2047 0 2047
#设置权限位600
[root@oldboyedu ~]# chmod 600 /root/swap_file
#添加swap大小
[root@oldboyedu ~]# swapon -f /root/swap_file
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 1980 108 497 9 1374 1678
Swap: 3047 0 3047
6. RAID概述
#1. 得到了更大的容量
#2. 得到的数据安全，冗余。
#3. 得到更好的性能。
RAID级别
RAID0 1 5 10
特点
RAID0：（条带卷） N*单块容量 最少两块，（支持一块） 读写最快 没有容错机制 只要求速度，不要求安全。
RAID1:（镜像卷） 一半 只能两块 读一般，写特慢 50% 只要求安全，不要求速度
RAID5：（校验卷） 浪费一块 至少三块， 读写稍快 只能坏一块 对安全和速度要求都不高。
RAID10： RAID1+RAID0 （镜像条带卷） 一般 至少4块 读写很快 50% 对安全和速度都有要求
总结：
冗余从好到坏：RAID1---RAID10---RAID5---RAID0
性能从好到差：RAID0---RAID10---RAID5---RAID1
价格从低到高：RAID0---RAID5---RAID1---RAID10
“`
7 LVM逻辑卷
“`
物理卷（PV）
卷组（VG）
逻辑卷（LV）
基本单元（PE）大小4MB
```
### 11. LVM实战
```shell
环境准备
[root@oldboyedu ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 2G 0 part [SWAP]
└─sda3 8:3 0 47.8G 0 part /
sdb 8:16 0 20G 0 disk
sdc 8:32 0 20G 0 disk
#下载软件包
[root@oldboyedu ~]# yum install -y lvm2
#创建物理卷
[root@oldboyedu ~]# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created.
#创建卷组并添加物理卷
[root@oldboyedu ~]# vgcreate lvm_test /dev/sdb
Volume group "lvm_test" successfully created
#创建逻辑卷
[root@oldboyedu ~]# lvcreate -L 1G -n lvm1 lvm_test
Logical volume "lvm1" created.
#检查
[root@oldboyedu ~]# vgs
VG #PV #LV #SN Attr VSize VFree
lvm_test 1 1 0 wz--n- <20.00g <19.00g
[root@oldboyedu ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lvm1 lvm_test -wi-a----- 1.00g
[root@oldboyedu ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb lvm_test lvm2 a-- <20.00g <19.00g
#根据卷组大小比例进行分配大小
[root@oldboyedu ~]# lvcreate -l 20%FREE -n lvm2 lvm_test
Logical volume "lvm2" created.
#格式化逻辑卷
[root@oldboyedu ~]# mkfs.xfs /dev/lvm_test/lvm1
meta-data=/dev/lvm_test/lvm1 isize=512 agcount=4, agsize=65536 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=262144, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
#创建挂载点，并进行挂载
[root@oldboyedu ~]# mkdir /lvm1
[root@oldboyedu ~]#
[root@oldboyedu ~]#
[root@oldboyedu ~]# mount /dev/lvm_test/lvm1 /lvm1
[root@oldboyedu ~]# ll /lvm1
total 0
[root@oldboyedu ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 48G 4.1G 44G 9% /
devtmpfs 980M 0 980M 0% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 9.6M 981M 1% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 197M 105M 93M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
/dev/mapper/lvm_test-lvm1 1014M 33M 982M 4% /lvm1
8.卷组的管理
#扩大卷组的大小
#扩大卷组的大小
[root@oldboyedu ~]# pvcreate /dev/sdc
Physical volume "/dev/sdc" successfully created.
[root@oldboyedu ~]# vgextend lvm_test /dev/sdc
Volume group "lvm_test" successfully extended
[root@oldboyedu ~]# vgs
VG #PV #LV #SN Attr VSize VFree
lvm_test 2 2 0 wz--n- 39.99g <35.20g
[root@oldboyedu ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb lvm_test lvm2 a-- <20.00g <15.20g
/dev/sdc lvm_test lvm2 a-- <20.00g <20.00g
#缩减卷组的大小
[root@oldboyedu ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb lvm_test lvm2 a-- <20.00g <15.20g
/dev/sdc lvm_test lvm2 a-- <20.00g <20.00g
[root@oldboyedu ~]# pvmove /dev/sdb /dev/sdc
/dev/sdb: Moved: 1.14%
/dev/sdb: Moved: 20.85%
/dev/sdb: Moved: 100.00%
[root@oldboyedu ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb lvm_test lvm2 a-- <20.00g <20.00g
/dev/sdc lvm_test lvm2 a-- <20.00g <15.20g
[root@oldboyedu ~]# vgreduce lvm_test /dev/sdb
Removed "/dev/sdb" from volume group "lvm_test"
[root@oldboyedu ~]# vgs
VG #PV #LV #SN Attr VSize VFree
lvm_test 1 2 0 wz--n- <20.00g <15.20g
**逻辑卷的管理**
#扩容
[root@oldboyedu ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lvm1 lvm_test -wi-ao---- 1.00g
lvm2 lvm_test -wi-a----- <3.80g
[root@oldboyedu ~]# lvextend -L +1G /dev/lvm_test/lvm1
Size of logical volume lvm_test/lvm1 changed from 1.00 GiB (256 extents) to 2.00 GiB (512 extents).
Logical volume lvm_test/lvm1 successfully resized.
[root@oldboyedu ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lvm1 lvm_test -wi-ao---- 2.00g
lvm2 lvm_test -wi-a----- <3.80g
[root@oldboyedu ~]# xfs_growfs /dev/lvm_test/lvm1
meta-data=/dev/mapper/lvm_test-lvm1 isize=512 agcount=4, agsize=65536 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=262144, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 262144 to 524288
[root@oldboyedu ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 48G 4.1G 44G 9% /
devtmpfs 980M 0 980M 0% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 9.6M 981M 1% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 197M 105M 93M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
/dev/mapper/lvm_test-lvm1 2.0G 33M 2.0G 2% /lvm1
[root@oldboyedu ~]# dd /lvm1/test.txt bs=100M count=18
18+0 records in
18+0 records out
1887436800 bytes (1.9 GB) copied, 3.96192 s, 476 MB/s
[root@oldboyedu ~]# ll -h /lvm1/
total 1.8G
-rw-r--r-- 1 root root 1.8G Aug 3 17:26 test.txt
#删除逻辑卷
[root@oldboyedu ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 48G 4.1G 44G 9% /
devtmpfs 980M 0 980M 0% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 9.6M 981M 1% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 197M 105M 93M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
/dev/mapper/lvm_test-lvm1 4.9G 1.8G 3.1G 38% /lvm1
[root@oldboyedu ~]# umount /lvm1/
[root@oldboyedu ~]#
[root@oldboyedu ~]# lvremove /dev/lvm_test/lvm1
Do you really want to remove active logical volume lvm_test/lvm1? [y/n]: y
Logical volume "lvm1" successfully removed
“`
磁盘故障
“`shell
环境准备
[root@oldboyedu ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 2G 0 part [SWAP]
└─sda3 8:3 0 47.8G 0 part /
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 200M 0 part
sr0 11:0 1 4.3G 0 rom
[root@oldboyedu ~]# mkfs.xfs /dev/sdb1
[root@oldboyedu ~]# mount /dev/sdb1 /block
#出现报错
[root@oldboyedu ~]# cp test.txt /block/
cp: error writing ‘/block/test.txt’: No space left on device
cp: failed to extend ‘/block/test.txt’: No space left on device
[root@oldboyedu ~]#
#解决思路
[root@oldboyedu ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 48G 4.1G 44G 9% /
devtmpfs 980M 0 980M 0% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 9.6M 981M 1% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 197M 105M 93M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
/dev/sdb1 1014M 1014M 32K 100% /block
#查找大文件
[root@oldboyedu ~]# du -sh /* |grep G
#经过领导的同意再去处理
rm -f
#inode号满了
[root@oldboyedu ~]# touch /inode/123
touch: cannot touch ‘/inode/123’: No space left on device
#排查思路
[root@oldboyedu ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 48G 4.1G 44G 9% /
devtmpfs 980M 0 980M 0% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 9.6M 981M 1% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 197M 105M 93M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
/dev/sdb1 1014M 1014M 32K 100% /block
/dev/sdb2 197M 64M 133M 33% /inode
[root@oldboyedu ~]# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/sda3 25062912 73014 24989898 1% /
devtmpfs 250789 416 250373 1% /dev
tmpfs 253514 1 253513 1% /dev/shm
tmpfs 253514 766 252748 1% /run
tmpfs 253514 16 253498 1% /sys/fs/cgroup
/dev/sda1 102400 325 102075 1% /boot
tmpfs 253514 1 253513 1% /run/user/0
/dev/sdb1 128 5 123 4% /block
/dev/sdb2 102592 102592 0 100% /inode
#查找大于1MB的目录
[root@oldboyedu ~]# find / -type d -size +1M |xargs ls -lhd
drwxr-xr-x 2 root root 2.4M Aug 3 18:00 /inode/test/data
#检查
[root@oldboyedu ~]# ll /inode/test/data |wc -l
102401
#经过领导的同意，是否可以删除
[root@oldboyedu ~]# find /inode/test/data -type f -name "*.txt" -delete
[root@oldboyedu ~]# find /inode/test/data -type f -name "*.log" -delete