Linux 为阿里云服务器新添加一块磁盘

短命女 2022-01-27 23:11 282阅读 0赞

今天在学习阿里云的快照功能时，发现公司每个 ECS 实例下磁盘有系统盘和数据盘两种：

![20190522164618153.png][]

关于系统盘和数据盘，阿里云的官方文档描述如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjU5NTAxMg_size_16_color_FFFFFF_t_70][]

按我的理解，系统盘和数据盘同为阿里云的块存储设备，无本质上的差别，唯一的区别在于，系统盘是随着 ECS 实例创建时，自动挂载到实例中，作为 Linux 中必不可少第一块磁盘，而数据盘则用于磁盘空间扩容，会自动装载到 ESC 实例中，但是需要分区、格式化、挂载后才能使用。

我们公司之前的操作人员在购买 ECS 实例时，为每个 ECS 实例额外购买了 200 个 G 的数据盘，但并未投入生产使用，现在每个服务器依然只有 40 个 G 的存储空间。

查看分区类型：

[root@manager-117 ~]# lsblk
    NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
    vda    253:0    0   40G  0 disk 
    └─vda1 253:1    0   40G  0 part /
    [root@manager-117 ~]# parted /dev/vda print 
    Model: Virtio Block Device (virtblk)
    Disk /dev/vda: 42.9GB
    Sector size (logical/physical): 512B/512B
    Partition Table: msdos
    Disk Flags: 
    
    Number  Start   End     Size    Type     File system  Flags
     1      1049kB  42.9GB  42.9GB  primary  ext4         boot

上面分区表类型显示的 msdos ，表示磁盘是 MBR 分区类型，MBR 分区使用 fdisk 命令磁盘分区，GPT分区使用 gdisk 命令磁盘分区；

使用 fdisk 查看是否存在没有分区的磁盘：

[root@manager-117 ~]# fdisk -l
    
    Disk /dev/vda: 42.9 GB, 42949672960 bytes, 83886080 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: 0x0008d73a
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/vda1   *        2048    83884031    41940992   83  Linux
    
    Disk /dev/vdb: 214.7 GB, 214748364800 bytes, 419430400 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@manager-117 ~]#

上面表示 系统中已经装载了一块新磁盘 /dev/vdb, 大小为214.7个G，但并未进行挂载使用；

将该磁盘添加到系统中：

**第一步：分区**

[root@manager-117 ~]# fdisk /dev/vdb
    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 0xba6dca54.
    
    Command (m for help): p
    
    Disk /dev/vdb: 214.7 GB, 214748364800 bytes, 419430400 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: 0xba6dca54
    
       Device Boot      Start         End      Blocks   Id  System
    
    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): 
    First sector (2048-419430399, default 2048): 
    Using default value 2048
    Last sector, +sectors or +size{K,M,G} (2048-419430399, default 419430399): 
    Using default value 419430399
    Partition 1 of type Linux and of size 200 GiB is set
    
    Command (m for help): w
    The partition table has been altered!
    
    Calling ioctl() to re-read partition table.
    Syncing disks.

**第二步：格式化**

[root@manager-117 ~]# mkfs -t ext4 /dev/vdb1
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    Stride=0 blocks, Stripe width=0 blocks
    13107200 inodes, 52428544 blocks
    2621427 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=2199912448
    1600 block groups
    32768 blocks per group, 32768 fragments per group
    8192 inodes per group
    Superblock backups stored on blocks: 
            32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
            4096000, 7962624, 11239424, 20480000, 23887872
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done

**第三步：挂载**

[root@manager-117 ~]# mkdir /data
    [root@manager-117 ~]# mount /dev/vdb1 /data

查看是否生效：

[root@manager-117 ~]# df -hT
    Filesystem     Type      Size  Used Avail Use% Mounted on
    /dev/vda1      ext4       40G  8.2G   30G  22% /
    devtmpfs       devtmpfs   16G     0   16G   0% /dev
    tmpfs          tmpfs      16G     0   16G   0% /dev/shm
    tmpfs          tmpfs      16G  1.7M   16G   1% /run
    tmpfs          tmpfs      16G     0   16G   0% /sys/fs/cgroup
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/983380badcc0be507c6d06b5be709c97b47cdd85d79c715243f9fc07116417c5/merged
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/516a25698415edc61d19f84efac8e4e1f527e87198be7b162d81bb31fdeae92c/merged
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/5c9c523e0e88b12064e943324b20b5e12e190a5b06ffe24b71560d64a904e9b2/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/5fe03ffe737bf07974debe1b342c2e6686f1bded544dfb708a7f298847daf812/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/ec71117f3c28b8e45a5091660cf3a61cff3f85096b600eaccf1accb937b49835/merged
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/dd94d5644aee5c729fd61a53b1d812660f6781c0a6562575f3a004fad54086c5/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/654f6d7b653ee718bdc401e2a9519d68e05cae05fcb4520d8408b32514256e56/shm
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/668915046ca6d12ffd95cb0a516d1a4a972e86c1909b6d77fee49cd699b7315a/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/2cd78f1ecbd336ecd68dd8601e33dd9ed7aa4ad369547693f4dd375f3b2de95b/merged
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/cc79290fa6045524cc491041072c0425790b65ba5c8f3c5b631796c37523ee9a/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/4d359227711da76c9c18ed42739a1434bc6b27e56ddd9a323f7b560e6a241b4b/shm
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/2b18d76ff658663506bc689396034672d433f2b61df75d3466e3d6ac3f87df7f/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/256beaa7ae061d0372648f063c715cb54d2771fd48b35168344b93190eb1957e/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/46457f18b4da731dd5414784ee03be566b4cd7dc27eba3662a2beaaf2a24002d/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/9af4017943e11e8638b0f3b8739e955852ddb7336637d002b6d360aaacc04254/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/1b26531a4f593f024db0ecaedcd2d82c25a1e439abc8602e9288a0a60eb97dbc/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/77f21520cd189edab98be30b848b8e0056003b462becca8d135f5a7c8a028d58/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/34d7b4d5584d820377e119756682ba06a9d64c06677c0851517b208c4de88355/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/b22de236151c1a95e3cf61811fe523ee9a80f0b28c0a8a665fb68cb250be75cb/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/666be0ccc3422e247b9baaac419bf67593306b182b38eb3a6e6f436a49e9752f/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/4721d2cf6e161b9f3b4459beaa58cb13ba29b52efe96a91b1f7cc30e11dc12ad/merged
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/23b48a996e87fbf128f8dcc20346f90b48b231015230ad25c1bdf963ba79686e/merged
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/88de1d1282dd17dbe9a6cf69b2a42e164e47333784c7b5ece9bad72d22d19dc5/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/2ab3a4af5c4b28194e2b54145c796f78ef04227476d76442904279e00b60cc1c/shm
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/c788033d7726e00610d81ff44a78782e5d96edada766a3621be222384f9f2c17/shm
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/c675e9f1ea8c4740a480d8e7e1bb120c81b4d886feb1b057fe5d696da5ca5c64/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/7530a155bb76f55dddf470cd45c29b5c3b8eb57cae664ddebd3df7b302f8305d/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/69234b2848255d46d834038caa187b3a2144fc8d5a4d4246bb3301ecac2b9869/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/28db3e41db46c8b3060661f2d6c3288915f1eafc23a69bbf64ae2ae0589bdb1f/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/40fafe723800602d4ab6a6ca48645058d943497e8c98aa54446312e6a658875a/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/c443b9cd9e2b8c2fe060b3f28c251e23a4245eba6211ec110a434c05e9b6675c/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/cf71512e3999b11b5cfbf62ac42f4c3343d9074ceb43647acc5b0b65e2bf2607/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/7f98a02f4521a260625ab8fadc512a8d86d511b503ff6aa5f5832ca47fd8854e/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/c41b80cbe8809609410d728c8693250e9e835409f4a90f18afe7988f84b58c4a/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/927876eae87803f3146c26957ef7c250668b3aa279a2e033ab297941acffc4c7/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/dfa3bca2dda6b924e9bd908d0ad1ef73e8500cb7d60f1a17c255092e1d081078/shm
    overlay        overlay    40G  8.2G   30G  22% /var/lib/docker/overlay/f2b5ae6c01cbf29de8268258810cebe33f4ad8daf29ac27c2753b80a4d7171d5/merged
    shm            tmpfs      64M     0   64M   0% /var/lib/docker/containers/1cd214f505a5a3483a0c32f0706694684abc56bc59887326e3f84ec525175515/shm
    tmpfs          tmpfs     3.2G     0  3.2G   0% /run/user/0
    /dev/vdb1      ext4      197G   61M  187G   1% /data

已将该磁盘挂载到 linux 系统中。

注意：使用 mount 命令挂载的分区在系统重启时会失效，需再次使用 mount 命令进行挂载，也可以编辑 /etc/fstab 文件设置开机自动挂载。

**第四步：设置开机自动挂载**

获取分区的 uuid：

[root@manager-117 ~]# blkid
    /dev/vda1: UUID="eb448abb-3012-4d8d-bcde-94434d586a31" TYPE="ext4" 
    /dev/vdb1: UUID="8ec5348c-3c98-4bd4-98eb-66b5c657927e" TYPE="ext4"

编辑 /etc/fstab 文件：

#
    # /etc/fstab
    # Created by anaconda on Sun Oct 15 15:19:00 2017
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    UUID=eb448abb-3012-4d8d-bcde-94434d586a31 /                       ext4    defaults        1 1
    UUID=8ec5348c-3c98-4bd4-98eb-66b5c657927e /data                   ext4    defaults        1 2

**关于 /etc/fstab 参数说明：**

第一列是要挂载的分区的标识。

可以是实际分区名，也可以是实际分区的卷标（Lable），或者是 UUID。

第二列是挂载点。

挂载点必须为当前已经存在的目录，最好为空目录。

第三列为此分区的文件系统类型。

此字段须与分区格式化时使用的类型相同，也可以使用 auto 这一特殊的语法，使系统自动侦测目标分区的分区类型。auto通常用于可移动设备的挂载。

第四列是挂载的选项。

用于设置挂载的参数，常见参数如下：

> auto 系统自动挂载，fstab默认就是这个选项；  
> defaults rw, suid, dev, exec, auto, nouser, and async；  
> noauto 开机不自动挂载；  
> nouser 只有超级用户可以挂载；  
> ro 按只读权限挂载；  
> rw 按可读可写权限挂载；  
> user 任何用户都可以挂载；  
> 请注意光驱和软驱只有在装有介质时才可以进行挂载，因此它是noauto。

第五列是dump备份设置。

当其值设置为1时，将允许dump备份程序备份；设置为0时，忽略备份操作；

第六列是fsck磁盘检查设置。

其值是一个顺序。当其值为0时，永远不检查；而 / 根目录分区永远都为1。其它分区从2开始，数字越小越先检查，如果两个分区的数字相同，则同时检查。

[20190522164618153.png]: /images/20220128/f246e8cf7b454a598b4dce17b5abdd11.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjU5NTAxMg_size_16_color_FFFFFF_t_70]: /images/20220128/c7125b1968094ec48383f6c39c3479ce.png