【CentOS 7筆記21】，磁盤掛載#171103

hellopasswd

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不進行分區直接格式化

[root@localhost ~]# fdisk -l /dev/sdb

	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: 0xa8f0c23e

	   Device Boot      Start         End      Blocks   Id  System

[root@localhost ~]# mkfs.xfs /dev/sdb
	mkfs.xfs: /dev/sdb appears to contain a partition table (dos).
	mkfs.xfs: Use the -f option to force overwrite.
[root@localhost ~]# mkfs.xfs -f /dev/sdb
	meta-data=/dev/sdb               isize=256    agcount=4, agsize=655360 blks
	         =                       sectsz=512   attr=2, projid32bit=1
	         =                       crc=0
	data     =                       bsize=4096   blocks=2621440, imaxpct=25
	         =                       sunit=0      swidth=0 blks
	naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
	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@localhost ~]# blkid /dev/sdb
	/dev/sdb: UUID="ad9ebef7-36c8-4395-a697-ffd8ae481541" TYPE="xfs"

格式化分區的目的是爲了掛載文件系統，Linux要想訪問磁盤必須掛載掛載點，掛載點其實就是一個目錄

mount掛載

[root@localhost ~]# mount /dev/sdb /mnt/
[root@localhost ~]# df -h
	Filesystem      Size  Used Avail Use% Mounted on
	/dev/sda3        28G  848M   27G   3% /
	devtmpfs        909M     0  909M   0% /dev
	tmpfs           914M     0  914M   0% /dev/shm
	tmpfs           914M  8.5M  905M   1% /run
	tmpfs           914M     0  914M   0% /sys/fs/cgroup
	/dev/sda1       197M   75M  123M  38% /boot
	/dev/sdb         10G   33M   10G   1% /mnt
[root@localhost ~]# mount | grep /dev/sd
	/dev/sda3 on / type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
	/dev/sda1 on /boot type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
	/dev/sdb on /mnt type xfs (rw,relatime,seclabel,attr2,inode64,noquota)

umount卸載

[root@localhost ~]# cd /mnt/
[root@localhost mnt]# ls
[root@localhost mnt]# ls
[root@localhost mnt]# touch 1.txt 2.txt
[root@localhost mnt]# mkdir 111
[root@localhost mnt]# ls
	111  1.txt  2.txt
[root@localhost mnt]# umount /dev/sdb
	umount: /mnt: target is busy.
	        (In some cases useful info about processes that use
	         the device is found by lsof(8) or fuser(1))
[root@localhost mnt]# pwd
	/mnt

當前在/mnt/目錄中，必須退出當前目錄才能夠繼續umount

[root@localhost mnt]# cd
[root@localhost ~]# umount /dev/sdb
[root@localhost ~]# df -h
	Filesystem      Size  Used Avail Use% Mounted on
	/dev/sda3        28G  846M   27G   3% /
	devtmpfs        909M     0  909M   0% /dev
	tmpfs           914M     0  914M   0% /dev/shm
	tmpfs           914M  8.5M  905M   1% /run
	tmpfs           914M     0  914M   0% /sys/fs/cgroup
	/dev/sda1       197M   75M  123M  38% /boot

當繼續掛載目錄，

[root@localhost ~]# mount /dev/sdb /mnt/
[root@localhost ~]# cd /mnt
[root@localhost mnt]# ls
	111  1.txt  2.txt

umount -l能夠不用退出當前目錄，即可以直接umount

[root@localhost mnt]# umount /dev/sdb
	umount: /mnt: target is busy.
	        (In some cases useful info about processes that use
	         the device is found by lsof(8) or fuser(1))
[root@localhost mnt]# umount -l /dev/sdb
[root@localhost mnt]# df -h
	Filesystem      Size  Used Avail Use% Mounted on
	/dev/sda3        28G  846M   27G   3% /
	devtmpfs        909M     0  909M   0% /dev
	tmpfs           914M     0  914M   0% /dev/shm
	tmpfs           914M  8.5M  905M   1% /run
	tmpfs           914M     0  914M   0% /sys/fs/cgroup
	/dev/sda1       197M   75M  123M  38% /boot

經常使用

mount -o rw\ro
mount -o remount	#從新掛載

系統啓動默認掛載的磁盤

[root@localhost mnt]# vi /etc/fstab
	
	#
	# /etc/fstab
	# Created by anaconda on Tue Oct 17 21:12:03 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=915e2a85-8d48-4667-9001-eae59adccb98 /                       xfs     defaults        1 1
	UUID=f50883db-5558-4813-8053-67e97169c609 /boot                   xfs     defaults        1 2
	UUID=d0344494-65f1-4279-a595-76801470be33 swap                    swap    defaults        0 0

系統啓動默認掛載哪一個磁盤哪一個分區 第一列設備的設備號，第二列爲掛載點，第三列爲分區格式，第四列爲掛載選項，第五列爲是否備份，第六列爲優先級1 這裏能夠寫分區號，也能夠寫UUID，而UUID能夠經過blkid查看

[root@localhost mnt]# blkid
	/dev/sr0: UUID="2017-10-27-14-49-48-00" LABEL="20171027_144209" TYPE="iso9660" 
	/dev/sda1: UUID="f50883db-5558-4813-8053-67e97169c609" TYPE="xfs" 
	/dev/sda2: UUID="d0344494-65f1-4279-a595-76801470be33" TYPE="swap" 
	/dev/sda3: UUID="915e2a85-8d48-4667-9001-eae59adccb98" TYPE="xfs" 
	/dev/sdb: UUID="ad9ebef7-36c8-4395-a697-ffd8ae481541" TYPE="xfs" 
[root@localhost mnt]# mount UUID="ad9ebef7-36c8-4395-a697-ffd8ae481541" /mnt/
[root@localhost mnt]# df -h
	Filesystem      Size  Used Avail Use% Mounted on
	/dev/sda3        28G  846M   27G   3% /
	devtmpfs        909M     0  909M   0% /dev
	tmpfs           914M     0  914M   0% /dev/shm
	tmpfs           914M  8.5M  905M   1% /run
	tmpfs           914M     0  914M   0% /sys/fs/cgroup
	/dev/sda1       197M   75M  123M  38% /boot
	/dev/sdb         10G   33M   10G   1% /mnt

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【CentOS 7基礎筆記19】，磁盤分區
【CentOS 7基礎筆記20】，磁盤格式化
【CentOS 7基礎筆記21】，磁盤掛載
【CentOS 7基礎筆記22】，手動增長Swap空間
【CentOS 7基礎筆記23】， Logical Volume Manager邏輯卷管理
修改於 171103