摘要
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磁盘分区和格式化操作是比较接近硬件底层的操作,这两个操作也是至关重要的,决定了磁盘的使用效率和磁盘的数据安全。(相信现在应该没有什么特别的需要,一般都已经抛弃了ext2,ext4文件格式了吧~~~~,ext2,ext3,ext4,xfs ,等等文件系统格式的优缺点不在本文讨论范围,有想了解的百度即可啦)
本文也不讨论Windows的文件系统格式,比如什么DOS,fat16,fat32,ntfs这些啦,主要的是想说一下Linux下的分区表格式,那就是MBR和GPT和loop。
有些同学会奇怪,怎么还有一个loop,这里需要申明,loop是表示整盘分区的,意思就是整个硬盘作为一个独立的分区,比如,一个新的硬盘插到主板上后,Linux系统开机后,如果不出意外,将会lsblk命令可以看到,此时,不使用fdisk或者parted,gparted等分区格式化工具,直接 格式化整个硬盘,格式化完成后,此时的硬盘分区就是loop了。
假设我有一块新的硬盘被Linux系统识别为了sde, 那么,我只执行 mkfs.xfs /dev/sde 这个格式化命令,此时,这个硬盘就是loop分区格式啦!!!!!!!!~~~~~
下面将仔细讲解。
分区所使用的命令主要为fdisk和parted,查看磁盘的详细情况的命令主要为lsblk,blkid,df 这三个命令。
lsblk
盲猜这个命令是 list status block的缩写,当然, 这么理解也是会更记忆深刻:列出所有块设备的状态。用于列出所有可用块设备的信息,而且还能显示他们之间的依赖关系,但是它不会列出RAM盘的信息。块设备有硬盘,闪存盘,cd-ROM等等。lsblk命令包含在util-linux-ng包中,现在该包改名为util-linux。这个包带了几个其它工具,如dmesg。要安装lsblk,请在此处下载util-linux包。如果没有此命令, yum install util-linux-ng来安装该包即可。比如,我的虚拟机的所有磁盘信息是这样的:
[root@hdp-1 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
├─sda1 8:1 0 500M 0 part /boot
├─sda2 8:2 0 99.5G 0 part
│ ├─centos-root 253:0 0 65G 0 lvm /
│ ├─centos-swap 253:1 0 4.5G 0 lvm [SWAP]
│ ├─centos-var 253:2 0 20G 0 lvm /var
│ └─centos-home 253:3 0 10G 0 lvm /home
├─sda3 8:3 0 1023.5K 0 part
└─sda4 8:4 0 512B 0 part
sdb 8:16 0 22G 0 disk /mnt/newdata
sdc 8:32 0 3.7T 0 disk /opt/data
sr0 11:0 1 4.4G 0 rom
这里,表示有三个硬盘,sda,sdb,sdc,容量分别为100G,22G,3.7T,sda这个硬盘划分了两个分区,分别为sda1和sda2,sda2又是使用的lvm格式,并且每个分区的挂载点也列出来了,sda3和sda4容量基本可以忽略,并且没有进行挂载。sr0表示光驱,也没有挂载。
2. blkid
该命令显示所有已经格式化的分区详细信息,其中有UUID,该ID为系统随机分配的固定的唯一标识,因此,我们挂载的时候应该使用UUID写入/etc/fstab ,即使硬盘挂载顺序有变,依然保证挂载的有效(比如,我有很多硬盘,然后我把一个新的硬盘插到了某个旧的原有的硬盘位,而旧有的硬盘换位置啦,这个时候,可能sdb 就会变成sdd或者别的名字了,如果/etc/fstab 里写的是 诸如 /dev/sdb 这么固定的,那么,挂载必定会出错啦~~!!~~~~!!~~~~!!)
[root@hdp-1 ~]# blkid
/dev/sda1: UUID="e58de036-fbe2-4992-a1bc-00a7376febf0" TYPE="xfs"
/dev/sda2: UUID="oYYZPi-rGCZ-3ujF-CtkU-TB6h-qU03-kvkQjL" TYPE="LVM2_member"
/dev/sdb: UUID="0fe31ddd-9388-4b5f-ab21-28d6190eed94" TYPE="ext4"
/dev/sr0: UUID="2019-09-11-18-50-31-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"
/dev/sdc: UUID="42cf4e54-fd20-4956-9883-3688d27001d0" TYPE="ext4"
/dev/mapper/centos-root: UUID="05415307-263e-4430-9a13-88ae9fc9f0d9" TYPE="xfs"
/dev/mapper/centos-swap: UUID="9f28e7d2-5799-499c-98e1-f9cd1aeccd56" TYPE="swap"
/dev/mapper/centos-var: UUID="afd83464-82b4-4693-a86b-19d24dc5d4af" TYPE="xfs"
/dev/mapper/centos-home: UUID="7ef6f1af-c6a1-445e-93a8-560da49274f1" TYPE="xfs"
以上显示我所有的格式化过的分区,每个分区的文件系统类型也标识了出来,比如,/dev/sdb: UUID="0fe31ddd-9388-4b5f-ab21-28d6190eed94" TYPE="ext4" 表示 sdb这个硬盘格式化成了ext4文件系统,这个命令的用处就是查看并校验我们是否格式化成功的命令。
3. df
df 是一个古老的命令,该命令会显示所有已挂载到系统内的分区的使用情况,
[root@hdp-1 ~]# df -ah
Filesystem Size Used Avail Use% Mounted on
sysfs 0 0 0 - /sys
proc 0 0 0 - /proc
devtmpfs 3.9G 0 3.9G 0% /dev
securityfs 0 0 0 - /sys/kernel/security
tmpfs 3.9G 0 3.9G 0% /dev/shm
devpts 0 0 0 - /dev/pts
tmpfs 3.9G 9.0M 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
cgroup 0 0 0 - /sys/fs/cgroup/systemd
pstore 0 0 0 - /sys/fs/pstore
cgroup 0 0 0 - /sys/fs/cgroup/net_cls,net_prio
cgroup 0 0 0 - /sys/fs/cgroup/blkio
cgroup 0 0 0 - /sys/fs/cgroup/devices
cgroup 0 0 0 - /sys/fs/cgroup/pids
cgroup 0 0 0 - /sys/fs/cgroup/cpuset
cgroup 0 0 0 - /sys/fs/cgroup/memory
cgroup 0 0 0 - /sys/fs/cgroup/freezer
cgroup 0 0 0 - /sys/fs/cgroup/hugetlb
cgroup 0 0 0 - /sys/fs/cgroup/cpu,cpuacct
cgroup 0 0 0 - /sys/fs/cgroup/perf_event
configfs 0 0 0 - /sys/kernel/config
/dev/mapper/centos-root 65G 1.5G 64G 3% /
systemd-1 0 0 0 - /proc/sys/fs/binfmt_misc
mqueue 0 0 0 - /dev/mqueue
debugfs 0 0 0 - /sys/kernel/debug
hugetlbfs 0 0 0 - /dev/hugepages
/dev/sdb 22G 45M 21G 1% /mnt/newdata
/dev/sdc 3.7T 89M 3.5T 1% /opt/data
/dev/mapper/centos-home 10G 33M 10G 1% /home
/dev/sda1 497M 130M 368M 26% /boot
/dev/mapper/centos-var 20G 4.6G 16G 23% /var
tmpfs 799M 0 799M 0% /run/user/0
这里比较特殊的是cgroup文件系统,它的定义大概是这样的(docker和cgroup是深度绑定的,因此,在这里稍微提一下。):
Linux CGroup全称Linux Control Group, 是Linux内核的一个功能,用来限制,控制与分离一个进程组群的资源(如CPU、内存、磁盘输入输出等)。这个项目最早是由Google的工程师在2006年发起(主要是Paul Menage和Rohit Seth),最早的名称为进程容器(process containers)。在2007年时,因为在Linux内核中,容器(container)这个名词太过广泛,为避免混乱,被重命名为cgroup,并且被合并到2.6.24版的内核中去。然后,其它开始了他的发展。
Linux CGroupCgroup 可让您为系统中所运行任务(进程)的用户定义组群分配资源 — 比如 CPU 时间、系统内存、网络带宽或者这些资源的组合。您可以监控您配置的 cgroup,拒绝 cgroup 访问某些资源,甚至在运行的系统中动态配置您的 cgroup。
示例:
这里这个示例我是使用的vm虚拟机,操作系统是centos7.4,总共挂载了三块硬盘,硬盘的情况如下:
[root@hdp-1 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
├─sda1 8:1 0 500M 0 part /boot
├─sda2 8:2 0 99.5G 0 part
│ ├─centos-root 253:0 0 65G 0 lvm /
│ ├─centos-swap 253:1 0 4.5G 0 lvm [SWAP]
│ ├─centos-var 253:2 0 20G 0 lvm /var
│ └─centos-home 253:3 0 10G 0 lvm /home
├─sda3 8:3 0 1023.5K 0 part
└─sda4 8:4 0 512B 0 part
sdb 8:16 0 22G 0 disk /mnt/newdata
sdc 8:32 0 3.7T 0 disk /opt/data
sr0 11:0 1 4.4G 0 rom
这里提前说一下,我这个操作系统内有三种,sda是MBR分区表形式,sdb和c是loop分区表形式(也就是整盘挂载),GPT分区表后面在实现。
先容我卖一个关子,讲讲怎么看 MBR,GPT和loop的分区表信息吧~~~~~~~
A:查看MBR分区表信息:
dd if=/dev/sda of=mbr.hex bs=512 count=1
前面已经说了sda是MBR分区表,以上命令是复制备份分区表信息,将信息存放到名为mbr.hex这个文件内的,查看该文件的内容是如下命令:
hexdump -C mbr.hex
文件内容如下:
[root@hdp-1 ~]# !80
hexdump -C mbr.hex
00000000 eb 63 90 10 8e d0 bc 00 b0 b8 00 00 8e d8 8e c0 |.c..............|
00000010 fb be 00 7c bf 00 06 b9 00 02 f3 a4 ea 21 06 00 |...|.........!..|
00000020 00 be be 07 38 04 75 0b 83 c6 10 81 fe fe 07 75 |....8.u........u|
00000030 f3 eb 16 b4 02 b0 01 bb 00 7c b2 80 8a 74 01 8b |.........|...t..|
00000040 4c 02 cd 13 ea 00 7c 00 00 eb fe 00 00 00 00 00 |L.....|.........|
00000050 00 00 00 00 00 00 00 00 00 00 00 80 01 00 00 00 |................|
00000060 00 00 00 00 ff fa 90 90 f6 c2 80 74 05 f6 c2 70 |...........t...p|
00000070 74 02 b2 80 ea 79 7c 00 00 31 c0 8e d8 8e d0 bc |t....y|..1......|
00000080 00 20 fb a0 64 7c 3c ff 74 02 88 c2 52 be 05 7c |. ..d|<.t...R..||
00000090 b4 41 bb aa 55 cd 13 5a 52 72 3d 81 fb 55 aa 75 |.A..U..ZRr=..U.u|
000000a0 37 83 e1 01 74 32 31 c0 89 44 04 40 88 44 ff 89 |7...t21..D.@.D..|
000000b0 44 02 c7 04 10 00 66 8b 1e 5c 7c 66 89 5c 08 66 |D.....f..\|f.\.f|
000000c0 8b 1e 60 7c 66 89 5c 0c c7 44 06 00 70 b4 42 cd |..`|f.\..D..p.B.|
000000d0 13 72 05 bb 00 70 eb 76 b4 08 cd 13 73 0d 5a 84 |.r...p.v....s.Z.|
000000e0 d2 0f 83 de 00 be 85 7d e9 82 00 66 0f b6 c6 88 |.......}...f....|
000000f0 64 ff 40 66 89 44 04 0f b6 d1 c1 e2 02 88 e8 88 |d.@f.D..........|
00000100 f4 40 89 44 08 0f b6 c2 c0 e8 02 66 89 04 66 a1 |.@.D.......f..f.|
00000110 60 7c 66 09 c0 75 4e 66 a1 5c 7c 66 31 d2 66 f7 |`|f..uNf.\|f1.f.|
00000120 34 88 d1 31 d2 66 f7 74 04 3b 44 08 7d 37 fe c1 |4..1.f.t.;D.}7..|
00000130 88 c5 30 c0 c1 e8 02 08 c1 88 d0 5a 88 c6 bb 00 |..0........Z....|
00000140 70 8e c3 31 db b8 01 02 cd 13 72 1e 8c c3 60 1e |p..1......r...`.|
00000150 b9 00 01 8e db 31 f6 bf 00 80 8e c6 fc f3 a5 1f |.....1..........|
00000160 61 ff 26 5a 7c be 80 7d eb 03 be 8f 7d e8 34 00 |a.&Z|..}....}.4.|
00000170 be 94 7d e8 2e 00 cd 18 eb fe 47 52 55 42 20 00 |..}.......GRUB .|
00000180 47 65 6f 6d 00 48 61 72 64 20 44 69 73 6b 00 52 |Geom.Hard Disk.R|
00000190 65 61 64 00 20 45 72 72 6f 72 0d 0a 00 bb 01 00 |ead. Error......|
000001a0 b4 0e cd 10 ac 3c 00 75 f4 c3 00 00 00 00 00 00 |.....<.u........|
000001b0 00 00 00 00 00 00 00 00 e3 42 0b 00 00 00 80 20 |.........B..... |
000001c0 21 00 83 dd 1e 3f 00 08 00 00 00 a0 0f 00 00 dd |!....?..........|
000001d0 1f 3f 8e fe ff ff 00 a8 0f 00 00 40 70 0c 00 00 |.?.........@p...|
000001e0 02 00 83 20 20 00 01 00 00 00 ff 07 00 00 00 fe |... ...........|
000001f0 ff ff 83 fe ff ff 00 e8 7f 0c 01 00 00 00 55 aa |..............U.|
00000200
在末尾,可以看到mbr的标志:55aa,也就是说只要看到55aa,我们就应该可以确定,这个硬盘是MBR分区表形式啦。55aa是硬盘有效标志,若被篡改则系统认为硬盘损坏.早期一些dos下的病毒喜欢篡改这个标志,造成硬盘损坏,但是分区还在。比较出名的此类病毒比如熊猫烧香就是更改55aa标志啦。
B:
GPT分区表的查看
dd if=/dev/sdc of=gpt.hex bs=512 count=32
gpt标准的结构是32个扇区,所以这里要操作32次,即依次读取第一块硬盘的0~31扇区。
读取二进制文件的内容命令为:
hexdump -C gpt.hex
GPT暂时没有,后面补充该文件的内容
首先开头的是一个保护性的MBR,为的是兼容,和早期的MBR类似,以55AA作为结束。
接下来是GPT头,以UEFI PART作为头标识字符。
C:
loop分区表的查看
dd if=/dev/sdb of=loop.hex bs=512 count=1
文件内容如下:
[root@hdp-1 ~]# !82
hexdump -C loop.hex
00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000200
在查看sdc的分区表,发现内容和sdb是一样的:
[root@hdp-1 ~]# dd if=/dev/sdc of=sdc.hex bs=512 count=1
1+0 records in
1+0 records out
512 bytes (512 B) copied, 9.6962e-05 s, 5.3 MB/s
[root@hdp-1 ~]# hexdump -C sdc.hex
00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000200
有一个有意思的事情,我们如果查看光驱,也就是sr0的分区表 ,将会看到MBR分区表的标识,但是,你可以发现,后面的几行全是0:
[root@hdp-1 ~]# dd if=/dev/sr0 of=sr0.hex bs=512 count=1
1+0 records in
1+0 records out
512 bytes (512 B) copied, 0.000509761 s, 1.0 MB/s
[root@hdp-1 ~]# hexdump -C sr0.hex
00000000 33 ed 90 90 90 90 90 90 90 90 90 90 90 90 90 90 |3...............|
00000010 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 |................|
00000020 33 ed fa 8e d5 bc 00 7c fb fc 66 31 db 66 31 c9 |3......|..f1.f1.|
00000030 66 53 66 51 06 57 8e dd 8e c5 52 be 00 7c bf 00 |fSfQ.W....R..|..|
00000040 06 b9 00 01 f3 a5 ea 4b 06 00 00 52 b4 41 bb aa |.......K...R.A..|
00000050 55 31 c9 30 f6 f9 cd 13 72 16 81 fb 55 aa 75 10 |U1.0....r...U.u.|
00000060 83 e1 01 74 0b 66 c7 06 f1 06 b4 42 eb 15 eb 00 |...t.f.....B....|
00000070 5a 51 b4 08 cd 13 83 e1 3f 5b 51 0f b6 c6 40 50 |ZQ......?[Q...@P|
00000080 f7 e1 53 52 50 bb 00 7c b9 04 00 66 a1 b0 07 e8 |..SRP..|...f....|
00000090 44 00 0f 82 80 00 66 40 80 c7 02 e2 f2 66 81 3e |D.....f@.....f.>|
000000a0 40 7c fb c0 78 70 75 09 fa bc ec 7b ea 44 7c 00 |@|..xpu....{.D|.|
000000b0 00 e8 83 00 69 73 6f 6c 69 6e 75 78 2e 62 69 6e |....isolinux.bin|
000000c0 20 6d 69 73 73 69 6e 67 20 6f 72 20 63 6f 72 72 | missing or corr|
000000d0 75 70 74 2e 0d 0a 66 60 66 31 d2 66 03 06 f8 7b |upt...f`f1.f...{|
000000e0 66 13 16 fc 7b 66 52 66 50 06 53 6a 01 6a 10 89 |f...{fRfP.Sj.j..|
000000f0 e6 66 f7 36 e8 7b c0 e4 06 88 e1 88 c5 92 f6 36 |.f.6.{.........6|
00000100 ee 7b 88 c6 08 e1 41 b8 01 02 8a 16 f2 7b cd 13 |.{....A......{..|
00000110 8d 64 10 66 61 c3 e8 1e 00 4f 70 65 72 61 74 69 |.d.fa....Operati|
00000120 6e 67 20 73 79 73 74 65 6d 20 6c 6f 61 64 20 65 |ng system load e|
00000130 72 72 6f 72 2e 0d 0a 5e ac b4 0e 8a 3e 62 04 b3 |rror...^....>b..|
00000140 07 cd 10 3c 0a 75 f1 cd 18 f4 eb fd 00 00 00 00 |...<.u..........|
00000150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001b0 74 4d 00 00 00 00 00 00 00 33 53 08 00 00 80 00 |tM.......3S.....|
000001c0 01 00 00 3f e0 ff 00 00 00 00 00 00 8b 00 00 fe |...?............|
000001d0 ff ff ef fe ff ff 74 09 00 00 00 44 00 00 00 00 |......t....D....|
000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.|
00000200
上面我们是通过复制备份硬盘的分区表,根据它自己的特点,可以看出是哪一类的分区,那有没有更快速有效的方法呢?当然有了,这时候就需要 fdisk和parted命令啦;
一,fdisk
古老的硬盘分区程序,Linux自带的,只是这个程序只支持MBR分区,并且该命令是修改内存的,也就是说不按w键,将不会对任何改动生效。
例如,我将sdc这个硬盘转换成GPT后,使用命令 fdisk /dev/sdc 将会出现如下输出,
[root@hdp-1 ~]# fdisk /dev/sdc
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
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):
如果是MBR,fdisk将不会提示:
[root@hdp-1 ~]# fdisk /dev/sda
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):
二,parted命令
这个命令相比fdisk更新,因此,该程序向下兼容fdisk,也就是说可以分区MBR,也可以分区GPT,此命令是即时生效,这里需要注意,不同于fdisk哦,因此,该命令需要谨慎使用。查看分区类型的命令是 :parted 磁盘名称 print,比如看sdb和sdc
[root@hdp-1 ~]# parted /dev/sdb print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 23.6GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:
Number Start End Size File system Flags
1 0.00B 23.6GB 23.6GB ext4
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
sdb是整盘分区,loop,sdc就是GPT啦。
下面的命令是将硬盘分区为GPT : parted /dev/sdc mklabel gpt
其中的Warning: Partition(s) on /dev/sdc are being used.说的是硬盘在使用,如果强行更改分区表,数据将会全部丢失,选择当然是忽略Ignore啦,第二个是问要不要继续,当然是Yes啦。更改完后parted提示你要修改挂载配置文件 /etc/fstab。
Ignore/Cancel? Ignore
Warning: The existing disk label on /dev/sdc will be destroyed and all data on this disk will be lost. Do you want to continue?
Yes/No? Yes
Information: You may need to update /etc/fstab
[root@hdp-1 ~]# parted /dev/sdc mklabel gpt
Warning: Partition(s) on /dev/sdc are being used.
Ignore/Cancel? Ignore
Warning: The existing disk label on /dev/sdc will be destroyed and all data on this disk will be lost. Do you want to continue?
Yes/No? Yes
Information: You may need to update /etc/fstab.
[root@hdp-1 ~]# parted /dev/sdc
GNU Parted 3.1
Using /dev/sdc
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
以上仅仅是将磁盘sdc的分区表改为了GPT,还需要继续分区,命令是: mkpart mydata xfs
[root@hdp-1 ~]# parted /dev/sdc
GNU Parted 3.1
Using /dev/sdc
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mkpart mydata xfs
Start? 0
End? 20000
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? Ignore
(parted) print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 20.0GB 20.0GB mydata
(parted) quit
Information: You may need to update /etc/fstab.
通过命令parted mkpart mydata xfs 输入20000(单位是M,mydata是一个自定义的名称,可以随意,但最好有一定的意义,自己清楚比较好哦),我们分了一个20G的区,现在格式化后(命令为mkfs.xfs /dev/sdc1)可以通过命令 blkid看到我们新分出来的这个区啦
为什么是sdc1呢?因为,我们通过lsblk命令可以看到啦!!!!!!!!!
[root@hdp-1 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
├─sda1 8:1 0 500M 0 part /boot
├─sda2 8:2 0 99.5G 0 part
│ ├─centos-root 253:0 0 65G 0 lvm /
│ ├─centos-swap 253:1 0 4.5G 0 lvm [SWAP]
│ ├─centos-var 253:2 0 20G 0 lvm /var
│ └─centos-home 253:3 0 10G 0 lvm /home
├─sda3 8:3 0 1023.5K 0 part
└─sda4 8:4 0 512B 0 part
sdb 8:16 0 22G 0 disk
sdc 8:32 0 3.7T 0 disk
└─sdc1 8:33 0 18.6G 0 part
sr0 11:0 1 4.4G 0 rom
[root@hdp-1 ~]# mkfs.xfs /dev/sdc1
meta-data=/dev/sdc1 isize=512 agcount=4, agsize=1220702 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=4882808, 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
[root@hdp-1 ~]# blkid
/dev/sda1: UUID="e58de036-fbe2-4992-a1bc-00a7376febf0" TYPE="xfs"
/dev/sda2: UUID="oYYZPi-rGCZ-3ujF-CtkU-TB6h-qU03-kvkQjL" TYPE="LVM2_member"
/dev/sdb: UUID="0fe31ddd-9388-4b5f-ab21-28d6190eed94" TYPE="ext4"
/dev/sr0: UUID="2019-09-11-18-50-31-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"
/dev/mapper/centos-root: UUID="05415307-263e-4430-9a13-88ae9fc9f0d9" TYPE="xfs"
/dev/mapper/centos-swap: UUID="9f28e7d2-5799-499c-98e1-f9cd1aeccd56" TYPE="swap"
/dev/mapper/centos-var: UUID="afd83464-82b4-4693-a86b-19d24dc5d4af" TYPE="xfs"
/dev/mapper/centos-home: UUID="7ef6f1af-c6a1-445e-93a8-560da49274f1" TYPE="xfs"
/dev/sdc1: UUID="fbb45648-2580-43f1-8ea9-f03f1c911787" TYPE="xfs" PARTLABEL="mydata" PARTUUID="2f4a584a-4f87-490d-9ddf-76f407c2c190"
那,现在并不想只有一个分区怎么办呢?光一个sdc1太孤单啦,在分一个区吧!!! 命令是:parted /dev/sdc mkpart mydata2
[root@hdp-1 ~]# parted /dev/sdc mkpart mydata2
File system type? [ext2]? xfs
Start? 20000
End? 200000
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? Ignore
Information: You may need to update /etc/fstab.
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 20.0GB 20.0GB xfs mydata
2 20.0GB 200GB 180GB mydata2
好啦,现在我们在通过lsblk和blkid看看sdc这个硬盘什么样了吧!!!
[root@hdp-1 ~]# blkid
/dev/sda1: UUID="e58de036-fbe2-4992-a1bc-00a7376febf0" TYPE="xfs"
/dev/sda2: UUID="oYYZPi-rGCZ-3ujF-CtkU-TB6h-qU03-kvkQjL" TYPE="LVM2_member"
/dev/sdb: UUID="0fe31ddd-9388-4b5f-ab21-28d6190eed94" TYPE="ext4"
/dev/sr0: UUID="2019-09-11-18-50-31-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"
/dev/mapper/centos-root: UUID="05415307-263e-4430-9a13-88ae9fc9f0d9" TYPE="xfs"
/dev/mapper/centos-swap: UUID="9f28e7d2-5799-499c-98e1-f9cd1aeccd56" TYPE="swap"
/dev/mapper/centos-var: UUID="afd83464-82b4-4693-a86b-19d24dc5d4af" TYPE="xfs"
/dev/mapper/centos-home: UUID="7ef6f1af-c6a1-445e-93a8-560da49274f1" TYPE="xfs"
/dev/sdc1: UUID="fbb45648-2580-43f1-8ea9-f03f1c911787" TYPE="xfs" PARTLABEL="mydata" PARTUUID="2f4a584a-4f87-490d-9ddf-76f407c2c190"
/dev/sdc2: PARTLABEL="mydata2" PARTUUID="26b2660d-ef22-4d6c-86f4-f54740828971"
[root@hdp-1 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
├─sda1 8:1 0 500M 0 part /boot
├─sda2 8:2 0 99.5G 0 part
│ ├─centos-root 253:0 0 65G 0 lvm /
│ ├─centos-swap 253:1 0 4.5G 0 lvm [SWAP]
│ ├─centos-var 253:2 0 20G 0 lvm /var
│ └─centos-home 253:3 0 10G 0 lvm /home
├─sda3 8:3 0 1023.5K 0 part
└─sda4 8:4 0 512B 0 part
sdb 8:16 0 22G 0 disk
sdc 8:32 0 3.7T 0 disk
├─sdc1 8:33 0 18.6G 0 part
└─sdc2 8:34 0 167.7G 0 part
sr0 11:0 1 4.4G 0 rom
可以看到,又分了一个200G的名字叫mydata2的分区。以上分区操作,我们会发现使用M这个单位有点眼花啦,因为4t基本等于4000000M,光数0就很头疼啦,怎么办?可以指定单位是G啦,好了,现在就把所有分的区清理掉,命令是:parted /dev/sdc rm 1 parted /dev/sdc rm 2
[root@hdp-1 ~]# parted /dev/sdc rm 1
Information: You may need to update /etc/fstab.
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
如果你瞎写一个 不存在的分区序号,那么会简单报个错(比如,上面的分区已经删除完了,在执行一次 parted /dev/sdc rm 1):
[root@hdp-1 ~]# parted /dev/sdc rm 1
Error: Partition doesn't exist.
现在开始正式的分区啦,当然,首先我们要看看sdc到底是多大的硬盘,命令如下:
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
可以看到,是4080G,第一个分区我们要分4t大小,那么,命令是这样的(非交互式的哦,效果是和上面的一样的):
[root@hdp-1 ~]# parted /dev/sdc mkpart mydata xfs 0 4T
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? Ignore
Information: You may need to update /etc/fstab.
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 4080GB 4080GB xfs mydata
[root@hdp-1 ~]# blkid
/dev/sda1: UUID="e58de036-fbe2-4992-a1bc-00a7376febf0" TYPE="xfs"
/dev/sda2: UUID="oYYZPi-rGCZ-3ujF-CtkU-TB6h-qU03-kvkQjL" TYPE="LVM2_member"
/dev/sdb: UUID="0fe31ddd-9388-4b5f-ab21-28d6190eed94" TYPE="ext4"
/dev/sr0: UUID="2019-09-11-18-50-31-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"
/dev/mapper/centos-root: UUID="05415307-263e-4430-9a13-88ae9fc9f0d9" TYPE="xfs"
/dev/mapper/centos-swap: UUID="9f28e7d2-5799-499c-98e1-f9cd1aeccd56" TYPE="swap"
/dev/mapper/centos-var: UUID="afd83464-82b4-4693-a86b-19d24dc5d4af" TYPE="xfs"
/dev/mapper/centos-home: UUID="7ef6f1af-c6a1-445e-93a8-560da49274f1" TYPE="xfs"
/dev/sdc1: UUID="fbb45648-2580-43f1-8ea9-f03f1c911787" TYPE="xfs" PARTLABEL="mydata" PARTUUID="07e89474-b2b8-4259-8f99-4233c34dcd2d"
[root@hdp-1 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
├─sda1 8:1 0 500M 0 part /boot
├─sda2 8:2 0 99.5G 0 part
│ ├─centos-root 253:0 0 65G 0 lvm /
│ ├─centos-swap 253:1 0 4.5G 0 lvm [SWAP]
│ ├─centos-var 253:2 0 20G 0 lvm /var
│ └─centos-home 253:3 0 10G 0 lvm /home
├─sda3 8:3 0 1023.5K 0 part
└─sda4 8:4 0 512B 0 part
sdb 8:16 0 22G 0 disk
sdc 8:32 0 3.7T 0 disk
└─sdc1 8:33 0 3.7T 0 part
sr0 11:0 1 4.4G 0 rom
可以看到,非交互式可以直接格式化好分区,交互式并不会。因为4T大于4080G,因此,是全部分完的哦。
再次删除,重新划分分区,这次是3000G和1000G两个分区,那么,命令应该是这样的(这里有技巧的,下一个分区的开始是上一个分区的结束,这里请仔细理解):
[root@hdp-1 ~]# parted /dev/sdc mkpart mydata xfs 0 3000G
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? Ignore
Information: You may need to update /etc/fstab.
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 3000GB 3000GB xfs mydata
[root@hdp-1 ~]# parted /dev/sdc mkpart mydata2 xfs 3000G 4000G
Information: You may need to update /etc/fstab.
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 3000GB 3000GB xfs mydata
2 3000GB 4000GB 1000GB mydata2
这里需要注意,第二个分区因为分区的时候输入了Ignore,因此,指定的xfs并没有显示,我们需要专门对此分区格式化一下,也就是命令 :
特别注意,这样指定的xfs其实并没有什么卵用,还是需要格式化一下的,因为,你如果不格式化,直接挂载是可以成功的,但df命令显示的容量是不对的。
Number Start End Size File system Name Flags
1 17.4kB 3000GB 3000GB xfs mydata
mkfs.xfs /dev/sdc2 当然,也可以格式化成你想要的其它文件系统,比如ext4,这些都是没有什么问题的。
[root@hdp-1 ~]# mkfs.xfs /dev/sdc2
meta-data=/dev/sdc2 isize=512 agcount=4, agsize=61035136 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=244140544, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=119209, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 3000GB 3000GB xfs mydata
2 3000GB 4000GB 1000GB xfs mydata2
通过blkid我们查出sdc1的UUID,然后将这个UUID写入/etc/fstab 进行挂载就可以使用啦,当然,把这个写入/etc/fstab 文件内也是可以接受的---PARTUUID=4618b8db-269e-4255-ab88-e6c9e3c0ad9a
[root@hdp-1 ~]# blkid
/dev/sda1: UUID="e58de036-fbe2-4992-a1bc-00a7376febf0" TYPE="xfs"
/dev/sda2: UUID="oYYZPi-rGCZ-3ujF-CtkU-TB6h-qU03-kvkQjL" TYPE="LVM2_member"
/dev/sdb: UUID="0fe31ddd-9388-4b5f-ab21-28d6190eed94" TYPE="ext4"
/dev/sr0: UUID="2019-09-11-18-50-31-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos"
/dev/mapper/centos-root: UUID="05415307-263e-4430-9a13-88ae9fc9f0d9" TYPE="xfs"
/dev/mapper/centos-swap: UUID="9f28e7d2-5799-499c-98e1-f9cd1aeccd56" TYPE="swap"
/dev/mapper/centos-var: UUID="afd83464-82b4-4693-a86b-19d24dc5d4af" TYPE="xfs"
/dev/mapper/centos-home: UUID="7ef6f1af-c6a1-445e-93a8-560da49274f1" TYPE="xfs"
/dev/sdc1: UUID="fbb45648-2580-43f1-8ea9-f03f1c911787" TYPE="xfs" PARTLABEL="mydata" PARTUUID="12843991-0208-4615-9fdc-55d4548fe964"
/dev/sdc2: UUID="b8ff9af1-49ee-4994-8232-6f61cc0a5291" TYPE="xfs" PARTLABEL="mydata2" PARTUUID="4618b8db-269e-4255-ab88-e6c9e3c0ad9a"
[root@hdp-1 ~]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Wed Jul 7 04:05:33 2021
#
# 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
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=e58de036-fbe2-4992-a1bc-00a7376febf0 /boot xfs defaults 0 0
/dev/mapper/centos-home /home xfs defaults 0 0
/dev/mapper/centos-var /var xfs defaults 0 0
/dev/mapper/centos-swap swap swap defaults 0 0
/dev/sdb /mnt/newdata ext4 defaults 0 0
UUID=fbb45648-2580-43f1-8ea9-f03f1c911787 /opt/data xfs defaults 0 0
格式化后,挂载成功后,df命令将显示实际的准确的容量(文件系统毕竟也是要算容量的啊,当然会小很多啦。):
[root@hdp-1 ~]# df -ah
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 65G 1.5G 64G 3% /
systemd-1 - - - - /proc/sys/fs/binfmt_misc
mqueue 0 0 0 - /dev/mqueue
hugetlbfs 0 0 0 - /dev/hugepages
debugfs 0 0 0 - /sys/kernel/debug
/dev/sdb 22G 45M 21G 1% /mnt/newdata
/dev/sda1 497M 130M 368M 26% /boot
/dev/mapper/centos-home 10G 33M 10G 1% /home
/dev/mapper/centos-var 20G 4.6G 16G 23% /var
tmpfs 799M 0 799M 0% /run/user/0
binfmt_misc 0 0 0 - /proc/sys/fs/binfmt_misc
/dev/sdc2 931G 33M 931G 1% /mnt/mydata2
/dev/sdc1 2.7T 89M 2.6T 1% /opt/data
整盘分区也就是loop模式就是直接执行硬盘格式化命令,系统会认为这个硬盘是loop分区表啦,例子如下:
[root@hdp-1 ~]# mkfs.xfs -f /dev/sdc
meta-data=/dev/sdc isize=512 agcount=4, agsize=249036800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=996147200, imaxpct=5
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=486400, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@hdp-1 ~]# parted /dev/sdc print
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 4080GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:
Number Start End Size File system Flags
1 0.00B 4080GB 4080GB xfs
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