一 .存储管理

主要知识点: 基本分区、逻辑卷LVM、EXT3/4/XFS文件系统、RAID

从工作原理区分

1.1.初识硬盘

机械HDD

固态SSD

SSD的优势

SSD是摒弃传统磁介质，采用电子存储介质进行数据存储和读取的一种技术，突破了传统机械硬盘的性能瓶颈， 拥有极高的存储性能，被认为是存储技术发展的未来新星。　　 固态硬盘的全集成电路化、无任何机械运动部件的革命性设计，从根本上解决了在移动办公环境下，对于数据读

写稳定性的需求。全集成电路化设计可以让固态硬盘 做成任何形状。与传统硬盘相比，SSD固态电子盘具有以下优点：　　

• 第一，SSD不需要机械结构，完全的半导体化，不存在数据查找时间、延迟时间和磁盘寻道时间，数据存取速度快。
• 第二，SSD全部采用闪存芯片，经久耐用，防震抗摔，即使发生与硬物碰撞，数据丢失的可能性也能够降到最小。　　
• 第三，得益于无机械部件及FLASH闪存芯片，SSD没有任何噪音，功耗低。　
• 第四，质量轻，比常规1.8英寸硬盘重量轻20-30克，使得便携设备搭载多块SSD成为可能。同时因其完全半导体化

无结构限制，可根据实际情况设计成各种不同接口、形状的特殊电子硬盘。

硬盘尺寸

3.5寸 2.5寸 1.8寸

从插拔方式

热插拔

非热插拔

从硬盘接口

IDE —— SATA (Serial ATA)

SCSI —— SAS (Serial Attached SCSI) 即串行连接SCSI other —— PCIE FC

SAS(Serial Attached SCSI)即串行连接SCSI，是新一代的SCSI技术，和现在流行的Serial ATA(SATA)硬盘相同，

都是采用串行技术以获得更高的传输速度，并通过缩短连结线改善内部空间等。

硬盘设备命名

物理硬盘： /dev/sd[a-z]

KVM虚拟化：/dev/vd[a-z]　　

​ /dev/sd[a-z]

KVM增加硬盘

半虚拟化驱动磁盘： online

全虚拟化驱动磁盘： offline

HP服务器硬盘 /dev/cciss/c0d0 /dev/cciss/c0d0p1 //c0第一个控制器, d0第一块磁盘, p1分区1 /dev/cciss/c0d0p2 //c0第一个控制器, d0第一块磁盘, p2分区2

从存储连接方式

本地存储 例如DellR730本地磁盘

外部存储 scsi线 sata线 sas线 FC线

网络存储 以太网络(iscsi, glusterFS,ceph) FC网络

1.2.从分区方式区分

MBR <2TB 14个分区（4个主分区，扩展分区，逻辑分区） 例如: 3主 + 1扩展（n逻辑）

GPT >2TB 128个主分区 注意：从MBR转到GPT，或从GPT转换到MBR会导致数据全部丢失！

MBR:

==================================================

二.基本分区

基本分区(MBR|GPT) ----> Filesystem ----> mount

[root@newrain ~]# ll /dev/vd* brw-rw----. 1 root disk 253,  0 11月 30 15:02 /dev/vda brw-rw----. 1 root disk 253,  1 11月 30 15:02 /dev/vda1brw-rw----. 1 root disk 253, 16 11月 30 15:02 /dev/vdbbrw-rw----. 1 root disk 252, 32 11月 30 15:02 /dev/vdcT[root@newrain ~]# lsblk  NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINTvda    253:0    0  10G  0 disk  └─vda1 253:1 0  10G  0 part /vdb    253:16   0  10G  0 disk  vdc    252:32   0    8G  0 disk

2.1.fdisk

[root@newrain ~]# fdisk -l /dev/sdbDisk /dev/sdb: 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
[root@newrain ~]# 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 0xf5f6a455.Command (m for help): m
Command actiona   toggle a bootable flagb   edit bsd disklabelc   toggle the dos compatibility flagd   delete a partitiong   create a new empty GPT partition tableG   create an IRIX (SGI) partition tablel   list known partition typesm   print this menun   add a new partitiono   create a new empty DOS partition tablep   print the partition tableq   quit without saving changess   create a new empty Sun disklabelt   change a partition's system idu   change display/entry unitsv   verify the partition tablew   write table to disk and exitx   extra functionality (experts only)Command (m for help): n  # 创建一个新的分区
Partition type:p   primary (0 primary, 0 extended, 4 free)  e   extended
Select (default p): p    # 创建一个主分区
Partition number (1-4, default 1):   #分区编号
First sector (2048-20971519, default 2048):  #起始位置
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): +100M
Partition 1 of type Linux and of size 100 MiB is setCommand (m for help): p   #打印分区表Disk /dev/sdb: 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: 0xf5f6a455Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048      206847      102400   83  LinuxCommand (m for help): w     #将修改保存到磁盘
The partition table has been altered!Calling ioctl() to re-read partition table.
Syncing disks.

2.2 gdisk

[root@newrain ~]# yum install -y gdisk
[root@newrain ~]# gdisk /dev/sdb
GPT fdisk (gdisk) version 0.8.10
Partition table scan:MBR: MBR onlyBSD: not presentAPM: not presentGPT: not present
***************************************************************
Found invalid GPT and valid MBR; converting MBR to GPT format
in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by
typing 'q' if you don't want to convert your MBR partitions
to GPT format!
***************************************************************
Command (? for help): ?
b       back up GPT data to a file
c       change a partition's name
d       delete a partition
i       show detailed information on a partition
l       list known partition types
n       add a new partition
o       create a new empty GUID partition table (GPT)
p       print the partition table
q       quit without saving changes
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
x       extra functionality (experts only)
?       print this menu
Command (? for help): n
Partition number (2-128, default 2): 
First sector (34-20971486, default = 206848) or {+-}size{KMGTP}:                    
Last sector (206848-20971486, default = 20971486) or {+-}size{KMGTP}: +200M
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): 
Changed type of partition to 'Linux filesystem'Command (? for help): wFinal checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!Do you want to proceed? (Y/N): y  
OK; writing new GUID partition table (GPT) to /dev/sdb.
The operation has completed successfully.[root@newrain ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0   10G  0 disk 
├─sda1            8:1    0    1G  0 part /boot
└─sda2            8:2    0    9G  0 part ├─centos-root 253:0    0    8G  0 lvm  /└─centos-swap 253:1    0    1G  0 lvm  [SWAP]
sdb               8:16   0   10G  0 disk 
├─sdb1            8:17   0  100M  0 part 
└─sdb2            8:18   0  200M  0 part 
sr0              11:0    1  4.3G  0 rom

2.创建文件系统（格式化）centos7默认使用xfs

[root@newrain ~]# mkfs.xfs /dev/sdb1
meta-data=/dev/sdb1              isize=512    agcount=4, agsize=6400 blks=                       sectsz=512   attr=2, projid32bit=1=                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=25600, imaxpct=25=                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=855, version=2=                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0[root@newrain ~]# mkfs.ext4 /dev/sdb2
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
51200 inodes, 204800 blocks
10240 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=33816576
25 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

1. 挂载

[root@newrain ~]# mkdir /mnt/data1 /mnt/data2
#手动挂载，不推荐
#[root@newrain ~]# mount /dev/sdb1 /mnt/data1
#[root@newrain ~]# mount /dev/sdb2 /mnt/data2
#自动挂载，永久挂载
[root@newrain ~]# blkid /dev/sdb1 /dev/sdb2
/dev/sdb1: UUID="c57f4a9f-07fa-4d54-b826-3d110d752cb2" TYPE="xfs" PARTLABEL="Linux filesystem" PARTUUID="16052086-21b5-4630-9ae0-6f9e32aa72e8" 
/dev/sdb2: UUID="38ae8974-333b-40e0-9e0b-828f92326d7f" TYPE="ext4" PARTLABEL="Linux filesystem" PARTUUID="7c52bb47-cc9b-4969-9ab0-eda92182bc12" 
[root@newrain ~]# vim /etc/fstab
UUID="c57f4a9f-07fa-4d54-b826-3d110d752cb2" /mnt/data1 xfs defaults 0 0
UUID="38ae8974-333b-40e0-9e0b-828f92326d7f" /mnt/data2 ext4 defaults 0 0
[root@newrain ~]# mount -a
[root@newrain ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0   10G  0 disk 
├─sda1            8:1    0    1G  0 part /boot
└─sda2            8:2    0    9G  0 part ├─centos-root 253:0    0    8G  0 lvm  /└─centos-swap 253:1    0    1G  0 lvm  [SWAP]
sdb               8:16   0   10G  0 disk 
├─sdb1            8:17   0  100M  0 part /mnt/data1
└─sdb2            8:18   0  200M  0 part /mnt/data2
sr0              11:0    1  4.3G  0 rom

1. 取消挂载

umount 设备名称|挂载点
[root@newrain ~]# umount /dev/sdb1 /dev/sdb2

5.查看磁盘挂载

[root@newrain ~]# df -Th
Filesystem              Type      Size  Used Avail Use% Mounted on
/dev/mapper/centos-root xfs       8.0G  1.4G  6.7G  18% /
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/sda1               xfs      1014M  133M  882M  14% /boot
tmpfs                   tmpfs      98M     0   98M   0% /run/user/0
/dev/sdb1               xfs        97M  5.3M   92M   6% /mnt/data1
/dev/sdb2               ext4      190M  1.6M  175M   1% /mnt/data2[root@newrain ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               8:0    0   10G  0 disk 
├─sda1            8:1    0    1G  0 part /boot
└─sda2            8:2    0    9G  0 part ├─centos-root 253:0    0    8G  0 lvm  /└─centos-swap 253:1    0    1G  0 lvm  [SWAP]
sdb               8:16   0   10G  0 disk 
├─sdb1            8:17   0  100M  0 part /mnt/data1
└─sdb2            8:18   0  200M  0 part /mnt/data2
sr0              11:0    1  4.3G  0 rom