添加硬盘设备
向机器中新增一块硬盘后,需要分区、格式化、挂载操作。其中分区也可以省略,表示不对硬盘进行分区。
1.添加一块硬盘
建议在关机状态下添加/更换硬盘,否则可能会造成盘符漂移。按照udev设备管理器,通常按照sda~z(SATA/SAS)的顺序对识别到的硬盘进行排序。
添加硬盘后,可以使用fdisk -l命令来查看新添加的硬盘是否被识别到。
[root@superwu ~]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 969M 0 969M 0% /dev
tmpfs 984M 0 984M 0% /dev/shm
tmpfs 984M 9.6M 974M 1% /run
tmpfs 984M 0 984M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 17G 3.9G 14G 23% /
/dev/sr0 6.7G 6.7G 0 100% /media/cdrom
/dev/sda1 1014M 152M 863M 15% /boot
tmpfs 197M 16K 197M 1% /run/user/42
tmpfs 197M 3.4M 194M 2% /run/user/0
[root@superwu ~]# fdisk -l //可以查看新增的硬盘是否被识别到。
Disk /dev/sda: 20 GiB, 21474836480 bytes, 41943040 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
Disklabel type: dos
Disk identifier: 0x12b989df
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 2099199 2097152 1G 83 Linux
/dev/sda2 2099200 41943039 39843840 19G 8e Linux LVM
Disk /dev/sdb: 20 GiB, 21474836480 bytes, 41943040 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 /dev/mapper/rhel-root: 17 GiB, 18249416704 bytes, 35643392 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 /dev/mapper/rhel-swap: 2 GiB, 2147483648 bytes, 4194304 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
2.分区(fdisk)
对新增硬盘进行分区
[root@linuxprobe ~]# fdisk /dev/sdb Welcome to fdisk (util-linux 2.32.1). 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. Created a new DOS disklabel with disk identifier 0x88b2c2b0. Command (m for help): p //查看硬盘内已有的分区信息,其中包括了硬盘的容量大小、扇区个数等信息 Disk /dev/sdb: 20 GiB, 21474836480 bytes, 41943040 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 Disklabel type: dos Disk identifier: 0x88b2c2b0
Command (m for help): n //参数n添加新的分区 Partition type p primary (0 primary, 0 extended, 4 free) e extended (container for logical partitions) Select (default p): p //参数p创建主分区,输入参数e来创建扩展分区。
Partition number (1-4, default 1): 1 //输入主分区的编号,主分区的编号范围是1~4. First sector (2048-41943039, default 2048): 此处敲击回车即可 //定义起始的扇区位置,敲击回车键保留默认设置即可,系统会自动计算出最靠前的空闲扇区的位置。 Last sector, +sectors or +size{K,M,G,T,P} (2048-41943039, default 41943039): +2G //创建出一个容量为2GB的硬盘分区. Created a new partition 1 of type 'Linux' and of size 2 GiB.
Command (m for help): w //保存分区信息并退出 The partition table has been altered. Calling ioctl() to re-read partition table. Syncing disks.
在上述步骤执行完毕之后,Linux系统会自动把这个硬盘主分区抽象成/dev/sdb1设备文件。可以使用file命令查看该文件的属性,有些时候系统并没有自动把分区信息同步给Linux内核,可以输入partprobe命令手动将分区信息同步到内核,推荐连续两次执行该命令,效果会更好。如果使用这个命令都无法解决问题,那么就重启计算机吧,这个“杀手锏”百试百灵,一定会有用的。
[root@linuxprobe ]# file /dev/sdb1 /dev/sdb1: cannot open `/dev/sdb1' (No such file or directory) [root@linuxprobe ]# partprobe [root@linuxprobe ]# partprobe [root@linuxprobe ]# file /dev/sdb1 /dev/sdb1: block special
3.格式化硬盘设备(mkfs)
如果硬件存储设备没有进行格式化,则Linux系统无法得知怎么在其上写入数据。因此,在对存储设备进行分区后还需要进行格式化操作。
[root@linuxprobe ~]# mkfs.xfs /dev/sdb1 //将/dev/sdb1格式化为xfs文件系统。 meta-data=/dev/sdb1 isize=512 agcount=4, agsize=131072 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=0 = reflink=1 data = bsize=4096 blocks=524288, 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
4.挂载(mount)
首先是创建一个用于挂载设备的挂载点目录;其次使用mount命令将存储设备与挂载点进行关联;然后使用df -h命令来查看挂载状态和硬盘使用量信息;最后将挂载信息写入/etc/fstab配置文件。
[root@linuxprobe ~]# mkdir /newFS [root@linuxprobe ~]# mount /dev/sdb1 /newFS [root@linuxprobe ~]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 969M 0 969M 0% /dev tmpfs 984M 0 984M 0% /dev/shm tmpfs 984M 9.6M 974M 1% /run tmpfs 984M 0 984M 0% /sys/fs/cgroup /dev/mapper/rhel-root 17G 3.9G 14G 23% / /dev/sr0 6.7G 6.7G 0 100% /media/cdrom /dev/sda1 1014M 152M 863M 15% /boot tmpfs 197M 16K 197M 1% /run/user/42 tmpfs 197M 3.5M 194M 2% /run/user/0 /dev/sdb1 2.0G 47M 2.0G 3% /newFS
[root@superwu ~]# vim /etc/fstab # # /etc/fstab # Created by anaconda on Tue Jan 11 03:26:57 2022 # # 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. # # After editing this file, run 'systemctl daemon-reload' to update systemd # units generated from this file. # /dev/mapper/rhel-root / xfs defaults 0 0 UUID=d7f53471-c95f-44f2-aafe-f86bd5ecebd7 /boot xfs defaults 0 0 /dev/mapper/rhel-swap swap swap defaults 0 0 /dev/cdrom /media/cdrom iso9660 defaults 0 0 /dev/sdb1 /newFS xfs defaults 0 0
du命令用查看分区或目录所占用的磁盘容量大小,英文全称为“disk usage”,语法格式为“du -sh目录名称”。
[root@linuxprobe ~]# du -sh /newFS 39M /newFS/
添加交换分区
交换(SWAP)分区是一种通过在硬盘中预先划分一定的空间,然后把内存中暂时不常用的数据临时存放到硬盘中,以便腾出物理内存空间让更活跃的程序服务来使用的技术,其设计目的是为了解决真实物理内存不足的问题。
交换分区的划分建议:在生产环境中,交换分区的大小一般为真实物理内存的1.5~2倍。
例如从/dev/sdb中取出一个大小为5GB的主分区作为交换分区资源:
分区:
[root@linuxprobe ~]# fdisk /dev/sdb Welcome to fdisk (util-linux 2.32.1). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help): n Partition type p primary (1 primary, 0 extended, 3 free) e extended (container for logical partitions) Select (default p): p Partition number (2-4, default 2): 敲击回车即可 First sector (4196352-41943039, default 4196352): 敲击回车即可 Last sector, +sectors or +size{K,M,G,T,P} (4196352-41943039, default 41943039): +5G Created a new partition 2 of type 'Linux' and of size 5 GiB.
然后尝试修改硬盘的标识码,这里将其改成82(Linux swap)以方便以后知道它的作用:
Command (m for help): t //修改分区类型 Partition number (1,2, default 2): 2 //指定修改的分区编号 Hex code (type L to list all codes): L //查看有哪些分区类型 0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris 1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT- 2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT- 3 XENIX usr 3c PartitionMagic 84 OS/2 hidden or c6 DRDOS/sec (FAT- 4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx 5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data 6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / . 7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility 8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt 9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi ea Rufus alignment e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD eb BeOS fs f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ee GPT 10 OPUS 55 EZ-Drive a7 NeXTSTEP ef EFI (FAT-12/16/ 11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f0 Linux/PA-RISC b 12 Compaq diagnost 5c Priam Edisk a9 NetBSD f1 SpeedStor 14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f4 SpeedStor 16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ f2 DOS secondary 17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fb VMware VMFS 18 AST SmartSleep 65 Novell Netware b8 BSDI swap fc VMware VMKCORE 1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fd Linux raid auto 1c Hidden W95 FAT3 75 PC/IX bc Acronis FAT32 L fe LANstep 1e Hidden W95 FAT1 80 Old Minix be Solaris boot ff BBT Hex code (type L to list all codes): 82 //指定分区编号为82(Linux swap) Changed type of partition 'Linux' to 'Linux swap / Solaris'. Command (m for help): p Disk /dev/sdb: 20 GiB, 21474836480 bytes, 41943040 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 Disklabel type: dos Disk identifier: 0x7327c2a7 Device Boot Start End Sectors Size Id Type /dev/sdb1 2048 4196351 4194304 2G 83 Linux /dev/sdb2 4196352 14682111 10485760 5G 82 Linux swap / Solaris Command (m for help): w //保存分区信息并退出 The partition table has been altered. Syncing disks.
格式化:
mkswap命令用于对新设备进行交换分区格式化,英文全称为“make swap”,语法格式为“mkswap设备名称”。
[root@superwu ~]# mkswap /dev/sdb2 //对交换分区格式化需要使用专用命令mkswap。 Setting up swapspace version 1, size = 5 GiB (5368705024 bytes) no label, UUID=073d9fa9-4652-4b7c-aca3-4ed62032a142
挂载:
swapon命令用于激活新的交换分区设备,英文全称为“swap on”,语法格式为“swapon设备名称”。
[root@superwu ~]# free -m //挂载前swap容量 total used free shared buff/cache available Mem: 1966 1289 84 16 591 493 Swap: 2047 0 2047 [root@superwu ~]# swapon /dev/sdb2 //挂载 [root@superwu ~]# free -m //挂载后swap容量 total used free shared buff/cache available Mem: 1966 1294 79 16 591 488 Swap: 7167 0 7167
将挂载信息写入/etc/fstab文件。
[root@linuxprobe ~]# vim /etc/fstab # # /etc/fstab # Created by anaconda on Tue Jul 21 05:03:40 2020 # # 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. # # After editing this file, run 'systemctl daemon-reload' to update systemd # units generated from this file. # /dev/mapper/rhel-root / xfs defaults 1 1 UUID=812b1f7c-8b5b-43da-8c06-b9999e0fe48b /boot xfs defaults 1 2 /dev/mapper/rhel-swap swap swap defaults 0 0 /dev/cdrom /media/cdrom iso9660 defaults 0 0 /dev/sdb1 /newFS xfs defaults 0 0 /dev/sdb2 swap swap defaults 0 0
磁盘容量配额
使用磁盘容量配额服务来限制某位用户或某个用户组针对特定文件夹可以使用的最大硬盘空间或最大文件个数,一旦达到这个最大值就不再允许继续使用。
可以使用quota技术进行磁盘容量配额管理,从而限制用户的硬盘可用容量或所能创建的最大文件个数。quota技术还有软限制和硬限制的功能。
软限制:当达到软限制时会提示用户,但仍允许用户在限定的额度内继续使用。
硬限制:当达到硬限制时会提示用户,且强制终止用户的操作。
RHEL 8系统中已经安装了quota磁盘容量配额服务程序包,但存储设备却默认没有开启对quota技术的支持,此时需要手动编辑配置文件并重启一次系统,让系统中的启动目录(/boot)能够支持quota磁盘配额技术。
[root@linuxprobe ~]# vim /etc/fstab # # /etc/fstab # Created by anaconda on Tue Jul 21 05:03:40 2020 # # 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. # # After editing this file, run 'systemctl daemon-reload' to update systemd # units generated from this file. # /dev/mapper/rhel-root / xfs defaults 1 1 UUID=812b1f7c-8b5b-43da-8c06-b9999e0fe48b /boot xfs defaults,uquota 1 2 /dev/mapper/rhel-swap swap swap defaults 0 0 /dev/cdrom /media/cdrom iso9660 defaults 0 0 /dev/sdb1 /newFS xfs defaults 0 0 /dev/sdb2 swap swap defaults 0 0 [root@linuxprobe ~]# reboot
在重启系统后使用mount命令查看,即可发现/boot目录已经支持quota磁盘配额技术了:
[root@linuxprobe ~]# mount | grep boot /dev/sda1 on /boot type xfs (rw,relatime,seclabel,attr2,inode64,usrquota)