Linux磁盤管理及文件系統使用
- fdisk
- parted
- gdisk
- Linux中磁盤命名:
IDE類型:/dev/hd[a-z]
SCSI類型:/dev/sd[a-z] -
一塊磁盤經過哪些步驟才能夠使用:分區(非必需)-->格式化-->掛載;磁盤分區的類型有MBR(master boot record)和GPT(GUID Partition Table),主要區別在MBR只能分4個主分區超過需要分為邏輯分區,磁盤容量最大不超過2T,超過部分無法識別。
- MBR 也就是主引導記錄,位於硬盤的 0 磁道、0 柱面、1 扇區中,主要記錄了啟動引導程序和磁盤的分區表:
由於分區表大小固定:最多只能分4個,超過需要使用擴展分區來劃分邏輯分區,即使主分區再分配一個,邏輯分區命名從/dev/sda5開始。 - 分區
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fdisk:不適用於GPT分區。
1.查看磁盤分區信息:
用法:fdisk -l [-u] [device...]:列出指定磁盤設備上的分區情況;[root@xt ~]# fdisk -l Disk /dev/sda: 21.5 GB, 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 label type: dos Disk identifier: 0x00036ca6 Device Boot Start End Blocks Id System /dev/sda1 2048 20973567 10485760 83 Linux /dev/sda2 20973568 25167871 2097152 82 Linux swap / Solaris /dev/sda3 25167872 25692159 262144 83 Linux
2.分區管理,fdisk提供了交互接口來管理分區
用法:fdisk [options] <disk>[root@xt ~]# 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): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition:刪除分區 g create a new empty GPT partition table G create an IRIX (SGI) partition table l list known partition types m print this menu n add a new partition:創建新分區 o create a new empty DOS partition table p print the partition table:列出現有分區 q quit without saving changes :不保存退出 s create a new empty Sun disklabel t change a partition‘s system id:修改分區類型 u change display/entry units v verify the partition table w write table to disk and exit:保存退出 x extra functionality (experts only)
3.在已經分區並且已經掛載其中某個分區的磁盤設備上創建的新分區,內核可能無法直接識別,通知內核重讀分區表
查看:cat /proc/partitions
CentOS 5:partprobe [device]
CentOS 6,7:partx, kpartx
partx -a [device]
kpartx -af [device] - parted 、gdisk能夠使用GPT模式
1.查看磁盤信息
parted [options] [device][root@xt ~]# parted -l Model: VMware, VMware Virtual S (scsi) Disk /dev/sda: 21.5GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 1 1049kB 10.7GB 10.7GB primary xfs 2 10.7GB 12.9GB 2147MB primary linux-swap(v1) 3 12.9GB 13.2GB 268MB primary btrfs Error: /dev/sdb: unrecognised disk label Model: VMware, VMware Virtual S (scsi) Disk /dev/sdb: 3221GB Sector size (logical/physical): 512B/512B Partition Table: unknown Disk Flags:
2.分區管理
用法: parted device[root@xt ~]# parted /dev/sdb GNU Parted 3.1 Using /dev/sdb Welcome to GNU Parted! Type ‘help‘ to view a list of commands. (parted) help #查看幫助 align-check TYPE N check partition N for TYPE(min|opt) alignment help [COMMAND] print general help, or help on COMMAND mklabel,mktable LABEL-TYPE create a new disklabel (partition table) mkpart PART-TYPE [FS-TYPE] START END make a partition name NUMBER NAME name partition NUMBER as NAME print [devices|free|list,all|NUMBER] display the partition table, available devices, free space, all found partitions, or a particular partition quit exit program rescue START END rescue a lost partition near START and END rm NUMBER delete partition NUMBER select DEVICE choose the device to edit disk_set FLAG STATE change the FLAG on selected device disk_toggle [FLAG] toggle the state of FLAG on selected device set NUMBER FLAG STATE change the FLAG on partition NUMBER toggle [NUMBER [FLAG]] toggle the state of FLAG on partition NUMBER unit UNIT set the default unit to UNIT version display the version number and copyright information of GNU Parted (parted) print Error: /dev/sdb: unrecognised disk label Model: VMware, VMware Virtual S (scsi) Disk /dev/sdb: 3221GB Sector size (logical/physical): 512B/512B Partition Table: unknown Disk Flags: (parted) mklabel gpt #修改磁盤結構類型:"aix", "amiga", "bsd", "dvh", "gpt", "loop", "mac", "msdos", "pc98", or "sun" Warning: The existing disk label on /dev/sdb will be destroyed and all data on this disk will be lost. Do you want to continue? Yes/No? yes (parted) mkpart #交互式分區 Partition name? []? primary #分區名稱: primary", "logical", or "extended" File system type? [ext2]? ext4 #文件系統類型 Start? 0 End? 1000 #分配分區大小 Warning: The resulting partition is not properly aligned for best performance. Ignore/Cancel? Ignore (parted) print Model: VMware, VMware Virtual S (scsi) Disk /dev/sdb: 3221GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 17.4kB 1000MB 1000MB primary (parted) rm 1 #刪除分區1 (parted) p Model: VMware, VMware Virtual S (scsi) Disk /dev/sdb: 3221GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags ============================================================== (parted) mkpart primary 0 2000G # 方法2分區 mkpart part-type [fs-type] start end Warning: The resulting partition is not properly aligned for best performance. Ignore/Cancel? i (parted) p Model: VMware, VMware Virtual S (scsi) Disk /dev/sdb: 3221GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 17.4kB 2000GB 2000GB primary (parted) q Information: You may need to update /etc/fstab.
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centos7有更簡便工具:gdisk 與fdisk類似
[root@xt ~]# gdisk /dev/sdb GPT fdisk (gdisk) version 0.8.10 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. #默認是GPT模式 Command (? for help): ?#查看幫助 b back up GPT data to a file c change a partition‘s name d delete a partition i show detailed information on a partition l list known partition types n add a new partition o create a new empty GUID partition table (GPT) p print the partition table q quit without saving changes r recovery and transformation options (experts only) s sort partitions t change a partition‘s type code v verify disk w write table to disk and exit x extra functionality (experts only) ? print this menu ================================================ Command (? for help): n 添加新分區 Partition number (1-128, default 1): First sector (34-6291455966, default = 2048) or {+-}size{KMGTP}: +3T First sector (34-6291455966, default = 2048) or {+-}size{KMGTP}: Last sector (2048-6291455966, default = 6291455966) or {+-}size{KMGTP}: +3T Last sector (2048-6291455966, default = 6291455966) or {+-}size{KMGTP}: Current type is ‘Linux filesystem‘ Hex code or GUID (L to show codes, Enter = 8300): 8300 Changed type of partition to ‘Linux filesystem‘ ======查看分區信息 Command (? for help): p Disk /dev/sdb: 6291456000 sectors, 2.9 TiB Logical sector size: 512 bytes Disk identifier (GUID): FA9BB121-FD84-4955-95C3-D4F21890A508 Partition table holds up to 128 entries First usable sector is 34, last usable sector is 6291455966 Partitions will be aligned on 2048-sector boundaries Total free space is 2014 sectors (1007.0 KiB) Number Start (sector) End (sector) Size Code Name 1 2048 6291455966 2.9 TiB 8300 Linux filesystem
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格式化:低級格式化(分區之前進行,劃分磁道)、高級格式化(分區之後對分區進行,創建文件系統)
1.創建文件系統的工具:[root@xt ~]# mkfs mkfs.btrfs mkfs.ext2 mkfs.ext4 mkfs.xfs mkfs.cramfs mkfs.ext3 mkfs.minix
2.ext系列文件系統專用管理工具:mke2fs
mke2fs [OPTIONS] device -t {ext2|ext3|ext4}:指明要創建的文件系統類型 mkfs.ext4 = mkfs -t ext4 = mke2fs -t ext4 -b {1024|2048|4096}:指明文件系統的塊大小; -L LABEL:指明卷標; -j:創建有日誌功能的文件系統ext3; mke2fs -j = mke2fs -t ext3 = mkfs -t ext3 = mkfs.ext3 -i #:bytes-per-inode,指明inode與字節的比率;即每多少字節創建一個Indode; -N #:直接指明要給此文件系統創建的inode的數量; -m #:指定預留的空間,百分比; -O [^]FEATURE:以指定的特性創建目標文件系統;
3.檢測及修復文件系統工具 fsck.type e2fsck xfs_repair,修復文件建議離線修復
ext系列文件系統的專用工具: e2fsck : check a Linux ext2/ext3/ext4 file system e2fsck [OPTIONS] device -y:對所有問題自動回答為yes; -f:即使文件系統處於clean狀態,也要強制進行檢測; -b:superblock 超級快 fsck:check and repair a Linux file system -t fstype:指明文件系統類型; fsck -t ext4 = fsck.ext4 -a:無須交互而自動修復所有錯誤; -r:交互式修復; eg: e2fsck -v -y -b 163840 /dev/sdb7 當fsck修復不了時,使用該命令修復
4.查看文件系統屬性
dumpe2fs, tune2fs ,xfs_info -
掛載
創建好文件系統後要使用先得掛載:根文件系統這外的其它文件系統要想能夠被訪問,都必須通過“關聯”至根文件系統上的某個目錄來實現,此關聯操作即為“掛載”;此目錄即為“掛載點”;
1.掛載點:
事先必須存在
該使用未被或不會被其它進程使用到的目錄
工作目錄非空,原有文件會被覆蓋隱藏
2.查看當前掛載情況
mount
cat /etc/mtab
cat /proc/mounts3.mount掛載命令使用
mount [-nrw] [-t vfstype] [-o options] device dir命令選項: -r:readonly,只讀掛載; -w:read and write, 讀寫掛載; -n:默認設備掛載或卸載的操作會同步更新至/etc/mtab文件中;-n用於禁止此特性; -a:讀取/etc/fstab中沒有掛載的設備, mount all filesystems mentioned in fstab -t vfstype:指明要掛載的設備上的文件系統的類型;可省略,會通過blkid來判斷掛載設備的文件系統類型; -o options:掛載選項 sync/async:同步/異步操作; atime/noatime:文件或目錄在被訪問時是否更新其訪問時間戳; diratime/nodiratime:目錄在被訪問時是否更新其訪問時間戳; remount:重新掛載; acl:支持使用facl功能; # mount -o acl device dir # tune2fs -o acl device mount -o remount,acl /dev/sda3 /mnt ro:只讀 rw:讀寫 dev/nodev:此設備上是否允許創建設備文件; exec/noexec:是否允許運行此設備上的程序文件; auto/noauto: user/nouser:是否允許普通用戶掛載此文件系統; suid/nosuid:是否允許程序文件上的suid和sgid特殊權限生效; defaults:Use default options: rw, suid, dev, exec, auto, nouser, async, and relatime.
4.umount卸載命令
umount device|mount_point
註:當正在被某進程訪問時無法卸載
查看被誰占用
#lsof mount_point
#fuser -v mount_point
終止進程 訪問:
fuser -km mount_point - 如何開機自動掛載:
把設備信息寫入到配置文件:/etc/fstab
mount -a:可自動掛載定義在此文件中的所支持自動掛載的設備# /etc/fstab # Created by anaconda on Fri Jun 1 22:10:52 2018 # # 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=9633c392-6fa0-4e3b-814d-9a2c30c60085 / xfs defaults 0 0 UUID=402d2bec-0b46-4654-8c96-6d2ca74e5668 /boot btrfs subvol=boot 0 0 UUID=9bf9acd8-1001-4eb1-b3a6-464afb90645d swap swap defaults 0 0 一共6個字段: 1.要掛載的設備,最好使用設備的UUID 2.掛載點,swap類型特殊 3.文件系統類型 4.掛載選項,如同mount中options 5.轉儲頻率 6.自檢次序:0不檢查,1首先檢查,2次級檢查一般對系統盤做檢查,業務盤不檢查即可,若檢查異常導致系統無法啟動
blkid device #查看設備uuid,類型
- VMware添加一塊新磁盤,不重啟,fdisk -l沒有顯示。
1.查看主機總線號
root@node /]# ls /sys/class/scsi_host/
host0 host1 host2
2.重新掃描SCSI總線來添加設備
[root@node /]# echo "- - -" > /sys/class/scsi_host/host0/scan
[root@node /]# echo "- - -" > /sys/class/scsi_host/host1/scan
[root@node /]# echo "- - -" > /sys/class/scsi_host/host2/scan
3.重新查看
[root@xt ~]# fdisk -l
Disk /dev/sda: 21.5 GB, 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 label type: dos
Disk identifier: 0x00036ca6
Device Boot Start End Blocks Id System
/dev/sda1 2048 20973567 10485760 83 Linux
/dev/sda2 20973568 25167871 2097152 82 Linux swap / Solaris
/dev/sda3 25167872 25692159 262144 83 Linux
Disk /dev/sdb: 3221.2 GB, 3221225472000 bytes, 6291456000 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
Linux磁盤管理及文件系統使用