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27-磁盘管理(下)

27-磁盘管理(下)

作者: 杨丶子 | 来源:发表于2019-05-26 20:53 被阅读35次
    image
    先去虚拟机添加2块0.1G的磁盘,重启服务器后生效。
    image

    然后看一下添加的磁盘

    fdisk -l |grep 'sd[a-z]'
    [09:24 root@oldboy ~]# fdisk -l |grep 'sd[a-z]'
    Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 sectors
    /dev/sda1   *        2048      411647      204800   83  Linux
    /dev/sda2          411648     2508799     1048576   82  Linux swap / Solaris
    /dev/sda3         2508800    41943039    19717120   83  Linux
    Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 sectors
    Disk /dev/sdc: 106 MB, 106954752 bytes, 208896 sectors
    
    

    一.MBR

    Master Boot Record 主引导记录

    位置
    磁盘的开头(0磁头 0磁道 1扇区)
    0磁头 0磁道 1扇区 521字节前446字节
    0头 0道 1扇区 521bytes

    image

    二.分区类型

    image

    主分区-primary

    一个主分区要占用16个字节的分区表
    在一个磁盘中最多4个主分区
    一般必须要有

    扩展分区-extended

    磁盘最多只能有4个主分区
    扩展分区无法直接使用
    一个扩展分区也要占用16个字节的分区表
    一个磁盘中只能创建一个扩展分区
    数据必须放在扩展分区中的逻辑分区

    逻辑分区-logical

    需要先创建扩展分区
    存放数据

    三.分区命名规则

    a.硬盘名字

    1.sata/sas/scsi

    /dev/sd??
    按字母排列
    第一块硬盘 /dev/sda
    第二块硬盘 /dev/sdb

    2.云服务器(阿里云)

    /dev/vda
    /dev/vdb

    b.分区名字※

    主分区或扩展分区
    1-4
    /dev/sda1 /dev/sda4

    逻辑分区
    从5开始(>=5)
    /dev/sda5 (第一个逻辑分区)

    c.例子

    第3块sata磁盘的第2个主分区 /dev/sdc2
    第6块sas磁盘的第2个逻辑分区 /dedv/sdf6

    四. fdisk分区和parted分区

    fdisk分区 parted分区
    共同 磁盘分区 磁盘分区
    区别 支持2TB以内硬盘 大于2TB磁盘
    支持MBR分区表 MBR GPT(支持更大的硬盘和更大的主分区)

    \ fdisk分区


    1.创建2个分区 1个10MB的主分区 创建1个使用所有剩余空间的扩展 分区 1个20MB的逻辑分区

    1.创建主分区

    [15:35 root@oldboy ~]# 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.
    
    Command (m for help): n   \\新建分区
    Partition type:
       p   primary (0 primary, 0 extended, 4 free)
            主分区p   
       e   extended     
            扩展分区e   
    Select (default p):         
            默认就是p主分区
    Partition number (1-4, default 1): 
    分区号                 默认
    First sector (2048-208895, default 2048): 
    磁盘分区中第一个扇区(从哪里开始)  默认的
    Using default value 2048
    Last sector, +sectors or +size{K,M,G} (2048-208895, default 208895): +10M
    磁盘分区中最后1个扇区
    Partition 1 of type Linux and of size 10 MiB is set
    创建了分区号是1的10MB的分区
    Command (m for help): p
    
    Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0xa9b1cdab
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048       22527       10240   83  Linux
    
    

    2.创建扩展分区

    Command (m for help): n   \\新建分区
    Partition type:
       p   primary (1 primary, 0 extended, 3 free)
       e   extended   \\扩展分区
    Select (default p): e
    Partition number (2-4, default 2): 
    First sector (22528-208895, default 22528): 
    Using default value 22528
    Last sector, +sectors or +size{K,M,G} (22528-208895, default 208895): 
    Using default value 208895
    Partition 2 of type Extended and of size 91 MiB is set
    
    Command (m for help): p
    
    Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0xe5935118
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048       22527       10240   83  Linux
    /dev/sdb2           22528      208895       93184    5  Extended
    
    

    3.创建逻辑分区并保存退出

    Command (m for help): n   \\新建分区
    Partition type:
       p   primary (1 primary, 1 extended, 2 free)
       l   logical (numbered from 5)   //逻辑分区
    Select (default p): l
    Adding logical partition 5
    First sector (24576-208895, default 24576): 
    Using default value 24576
    Last sector, +sectors or +size{K,M,G} (24576-208895, default 208895): +20M          
    Partition 5 of type Linux and of size 20 MiB is set
    
    Command (m for help): p
    
    Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0xe5935118
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048       22527       10240   83  Linux
    /dev/sdb2           22528      208895       93184    5  Extended
    /dev/sdb5           24576       65535       20480   83  Linux
    
    Command (m for help): w   \\保存
    The partition table has been altered!
    
    Calling ioctl() to re-read partition table.
    Syncing disks.
    
    

    4.查看

    [10:42 root@oldboy ~]# ll /dev/sdb*
    brw-rw---- 1 root disk 8, 16 Apr 30 10:42 /dev/sdb
    brw-rw---- 1 root disk 8, 17 Apr 30 10:42 /dev/sdb1
    brw-rw---- 1 root disk 8, 18 Apr 30 10:42 /dev/sdb2
    brw-rw---- 1 root disk 8, 21 Apr 30 10:42 /dev/sdb5
    
    

    如何删除分区:(接下题先把创建的删除掉)

    Command (m for help): d  \\按从后往前删除
    
    

    2.创建1个使用磁盘所有容量的分区 并挂载到/mnt上(临时挂载点)

    1.第一个里程碑-创建分区

    [11:20 root@oldboy ~]# 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.
    
    Command (m for help): n \\新建分区
    Partition type:
       p   primary (0 primary, 0 extended, 4 free)
       e   extended
    Select (default p): p \\创建主分区
    Partition number (1-4, default 1): 
    First sector (2048-208895, default 2048): 
    Using default value 2048
    Last sector, +sectors or +size{K,M,G} (2048-208895, default 208895): 
    Using default value 208895
    Partition 1 of type Linux and of size 101 MiB is set
    
    Command (m for help): p
    
    Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0xe5935118
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1            2048      208895      103424   83  Linux
    
    Command (m for help): w
    The partition table has been altered!
    
    Calling ioctl() to re-read partition table.
    Syncing disks.
    
    

    2.第2个里程碑-格式化 创建文件系统

    mkfs.xfs /dev/sdb1

    [11:21 root@oldboy ~]# mkfs.xfs /dev/sdb1
    meta-data=/dev/sdb1              isize=512    agcount=4, agsize=6464 blks
             =                       sectsz=512   attr=2, projid32bit=1
             =                       crc=1        finobt=0, sparse=0
    data     =                       bsize=4096   blocks=25856, 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
    
    

    3.第3个里程碑-挂载

    • 临时挂载 mount /dev/sdb1 /mnt
    • 卸载 umount /mnt
    [11:24 root@oldboy ~]# df -h  \\查看已挂载的磁盘
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/sda3        19G  2.3G   17G  13% /
    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  133M   64M  68% /boot
    tmpfs           199M     0  199M   0% /run/user/0
    [11:24 root@oldboy ~]# mount /dev/sdb1 /mnt/     \\挂载
    [11:25 root@oldboy ~]# df -h      \\再次查看
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/sda3        19G  2.3G   17G  13% /
    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  133M   64M  68% /boot
    tmpfs           199M     0  199M   0% /run/user/0
    /dev/sdb1        98M  5.3M   93M   6% /mnt
    
    

    挂载分区中的报错与排错

    1.
    Changes will remain in memory only, until you decide to write them.
    你进行的修改默认存放在内存中,直到你决定保存这些修改的时候.
    :wq 
    Be careful before using the write command.
    保存之前小心点!
    Device does not contain a recognized partition table
    设备    没有    包含     磁盘分区表。
    DPT= disk  partition table  磁盘分区表
    
    
    2.
    mount /dev/sdb1 /mnt/
    mount: /dev/sdb1 is already mounted or /mnt busy
                    这个分区已经安装或 繁忙
    
    
    3.
    mkfs.xfs /dev/sdb1
    mkfs.xfs: /dev/sdb1 appears to contain an existing filesystem (ext4).
              这个磁盘分区中 已经包含了1个文件系统(已经格式化过了)
    mkfs.xfs: Use the -f option to force overwrite.
              如果强制格式化覆盖使用-f 
    
    
    4.
    [root@cuihua ~]# mount /dev/sdb1 /mnt
    mount: /dev/sdb1 is write-protected, mounting read-only
                            写保护         安装只读
    mount: unknown filesystem type '(null)'
           未知的文件系统类型(没有格式化)
    
    
    5.
    [root@guanggege ~]# mount  /dev/sdb1  /mnt/
    mount: special device /dev/sdb1 does not exist
           特殊文件(设备文件)     不存在   
    
    
    6.
    [root@oldboyedu59 ~]# mkfs.xfs  /dev/sdb1 
    mkfs.xfs: /dev/sdb1 contains a mounted filesystem
                 sdb1磁盘分区 包含  1个已经挂载的文件系统 (磁盘分区已经挂载)
    
    
    7.
    Invalid partition type `e'
    "e"是无效的分区类型 
    
    

    4.第四个里程碑-永久挂载※

    1./etc/rc.local

    file /etc/rc.d/rc.local
    /etc/rc.d/rc.local: Bourne-Again shell script, ASCII text executable     
                        shell脚本,可执行
    
    

    2./etc/fstab 开机自动挂载

    cat /etc/fstab 
    UUID=8a44a07b-1b45-49c1-b6aa-c5ab81c717c8   /           xfs         defaults      0     0
    UUID=2e59d872-2875-46bc-9e12-e59b9751ada1   /boot       xfs         defaults      0     0
    UUID=13d82528-a2cc-484e-b468-9dfc25c36f5c   swap        swap        defaults      0     0
    第一列.UUID或设备名称                   
    第二列.挂载点(入口)     
    第三列.文件系统类型      
    第四列.挂载参数  
    第五列.是否备份  
    第六列.是否开机自启动检查
    
    blkid     \\查询设备上所使用的文件系统类型、LABEL、UUID等信息
    /dev/sda1: UUID="2e59d872-2875-46bc-9e12-e59b9751ada1" TYPE="xfs" 
    /dev/sda2: UUID="13d82528-a2cc-484e-b468-9dfc25c36f5c" TYPE="swap" 
    /dev/sda3: UUID="8a44a07b-1b45-49c1-b6aa-c5ab81c717c8" TYPE="xfs" 
    /dev/sdb1: UUID="b6242409-4b32-4ff3-a46e-7dab26695139" TYPE="xfs" 
    /dev/sr0: UUID="2018-11-25-23-54-16-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"     
    
    为要挂载的磁盘添加一行 
    tail -1 /etc/fstab 
    /dev/sdb1                 /date               xfs     defaults    0   0  
    
    

    CentOS7 默认的是xfs文件类型
    CentOS6 5 默认 ext类型


    \ parted(修改实时生效)


    p   print   显示磁盘信息
    
    

    1.分区表

    1.创建分区表parted /dev/sdc

    [12:46 root@oldboy ~]# parted  /dev/sdc 
    GNU Parted 3.1
    Using /dev/sdc
    Welcome to GNU Parted! Type 'help' to view a list of commands.
    (parted) p                                                                
    Error: /dev/sdc: unrecognised disk label
    Model: VMware, VMware Virtual S (scsi)                                    
    Disk /dev/sdc: 107MB
    Sector size (logical/physical): 512B/512B
    Partition Table: unknown
    Disk Flags: 
    (parted) mktable gpt 
    (parted) p                                                                
    Model: VMware, VMware Virtual S (scsi)
    Disk /dev/sdc: 107MB
    Sector size (logical/physical): 512B/512B
    Partition Table: gpt
    Disk Flags: 
    
    Number  Start  End  Size  File system  Name  Flags
    
    
    1. mkpart primary指定大小
    (parted) mkpart primary 0 10  
    Warning: The resulting partition is not properly aligned for best
    performance.
    Ignore/Cancel? i                                                          
    (parted)                  
    
    

    3.查看创建是否成功

    (parted) p                                                                
    Model: VMware, VMware Virtual S (scsi)
    Disk /dev/sdc: 107MB
    Sector size (logical/physical): 512B/512B
    Partition Table: gpt
    Disk Flags: 
    
    Number  Start   End     Size    File system  Name     Flags
     1      17.4kB  10.0MB  9983kB               primary
    
    

    4.退出

    (parted) q
    Information: You may need to update /etc/fstab.   
    
    

    5.显示分区信息

    ll /dev/sdc*
    brw-rw---- 1 root disk 8, 32 Apr 30 12:51 /dev/sdc
    brw-rw---- 1 root disk 8, 33 Apr 30 12:51 /dev/sdc1   
    
    

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