Linux disk and File System Management (1) _ partition formatting

Linux disk and File System Management (1) _ partition formatting
Linux disk management Hard Disk: mechanical hard disk SSD solid state disk mechanical: track sector: minimum texture storage unit, each sector size is 512 bytes cylinder cylindrical: partition basic unit; the first sector of the hard disk is 512 bytes MBR: Master Boot Record the hard disk Master Boot records MBR accounted for 446 bytes: the bootloader Partition table (pratition table) occupies 64 bytes: in the filesystem allocation table partition table, each 16 bytes identifies a partition. Therefore, the primary partition and the extended partition can have up to four partitions. 2 bytes: 55AA flag, and 55AA indicates that the partition takes effect, others indicate invalid disk interface type: IDE (ATA): Speed 133 MB/s,/dev/hd SCSI: Speed 640 MB/s SATA: Speed 6 Gbps SAS: Speed 6 Gbps USB: speed: 480 MB/s hard disk device identification: names of disks with various interfaces in linux. After centos6, they are all named:/dev/sd * marked with Different Hard Disk devices: /dev/sd [a-z] Mark different partitions on the same device:/dev/sd [a-z] [1-] 1-4: name the primary or extended partition ID 5 +: Logical partition ID Device File: special file device number: major, minor major: indicates the device type minor: different devices of the same type "Block ": block, Random Device "character": character, linear device GPT: GUIDPartition Table disk management adds a new disk to the linux system. You need to partition the disk and format the partition, create available file system 3 create a mount point and mount it to the disk and directory capacity df command: list the overall disk usage of the file system report file system disk space usage Syntax: df [OPTION]... [FILE]... option:-a: List all file systems-k or-m: display the file system-h in units of KB, MB: easy to read GB, MB, display in KB or other formats-I: No need for hard disk capacity, displayed as inode quantity-T: Display partition file system type example:

# List the overall disk usage of the file system [root @ localhost ~] # DfFilesystem 1K-blocks Used Available Use % Mounted on/dev/sda3 9947976 551432 8868160 6%/devtmpfs 493016 493016 0%/devtmpfs 501580 501580 0% 501580/dev/shmtmpfs 6792 494788 2%/runtmpfs 501580 0 501580 0%/sys/fs/cgroup/dev/sda2 20027216 1112520 17874312 6%/usr/dev/sda1 194235 90696 89203 51%/boot/dev/sda5 9947976 36976 9382616 1%/home # display the format of each partition in the file system [root @ localhost ~] # Df-T Filesystem Type 1K-blocks Used Available Use % Mounted on/dev/sda3 ext4 9947976 551432 8868160 6%/devtmpfs 493016 0 493016/devtmpfs tmpfs 0% 0 501580/dev/shmtmpfs tmpfs 501580 6792 494788 2%/runtmpfs tmpfs 501580 0 501580 0%/sys/fs/cgroup/dev/sda2 ext4 20027216 1112520 17874312 6%/usr/dev/sda1 ext4 194235 90696 89203/boot /dev/sda5 ext4 9947976 36976 9382616 1%/ Home # [root @ localhost ~] # Df-ThFilesystem Type Size Used Avail Use % Mounted on/dev/sda3 ext4 9.5G 539 M 8.5G 6%/devtmpfs 482 M 0 482 M 0%/devtmpfs tmpfs 490 M 0 490 M 0%/dev/shmtmpfs tmpfs 490 M 6.7 M 484 M 2%/runtmpfs tmpfs 490 M 0 490 M 0%/sys/fs/cgroup/dev/sda2 ext4 20G 1.1G 18G 6%/usr/dev/sda1 ext4 190 M 89 M 88 M 51%/boot/dev/sda5 ext4 9.5G 37 M 9.0G 1%/home

 

Filesystem: Indicates each partition. device name Type: File System Format: 1k-blocks: 1 k indicates the unit of the following numbers: Used space Avail: available space Use %: disk usage Mounted on: disk mount point du command: Count the directory capacity du [OPTION]... [FILE]... parameter:-a: List all files and directory capacity-h: the unit of readable capacity is KB, MB, and GB.-s: list total-S: example of a total that does not contain subdirectories:

# Default analysis of the current directory without a directory or file name [root @ localhost test] # du4. /testbash28. [root @ localhost test] # du-a16. /functions4. /testbash4. /test_vim28. [root @ localhost test] # du-h4.0K. /testbash28K. [root @ localhost test] # du-sh/etc/22 M/etc/[root @ localhost test] # du-S4. /testbash24.

 

Partitioning: separates the storage space into multiple small spaces. Each space can use the file system independently. Partitioning tools: fdisk, parted, and sfdisk fdisk: A maximum of 15 partitions can be created on a hard disk. fdisk DEVICE: DEVICE indicates the DEVICE file name. Do not add a number to the back. The partition is for the entire hard disk DEVICE partition management sub-command: p: show current Partition Table n: Create new partition d: delete specified partition t: Modify partition ID l: list all supported partition types and IDs w: Save and exit q: discard modification and exit m: after obtaining help, check whether the kernel has recognized the new partition: # cat/proc/partitions has three commands to allow the kernel to re-read the disk partition table CentOS5: partprobe [DEVICE] CentOS6, 7. Command: partx kpartx partx command: partx DEVICE partx-a DEVICE registers all the partition information on a disk, as shown in figure If the partition information has been recorded, an error is reported. If the partition information on a disk is not recorded, it is completed quietly. Partx-a-n M: n device records the information of the nth to nth partitions. M reads the information of the nth partition. M: specifies the minimum value for reading the Partition Number: n: specify the maximum value of the read Partition Number. kpartx command: create a DEVICE ing from the partition table. kpartx-af DEVICE-a: Add a partition ing. Linux File System: VFS: virtual FileSystem ensures that all disk device interfaces can use Linux: ext2, ext3, ext4, reiserfs, xfs, btrfs, and swap optical disks: iso9660 Windows: fat32 (vfat), ntfs Unix: ffs, ufs, jfs, jfs2 Network File System: nfs, cifs Cluster File System: ocfs2, gfs2 Distributed File System: ceph, moosefs, mogilefs, hdfs, gfs, glusterfs (1) log File System Non-Log File System: ext2 Log File System: ext3 (2) swap: swap partition use the hard disk as the temporary memory to create a file system: to execute formatting (Advanced formatting) on a partition, you need to use a certain file system to meet two conditions: in the kernel: support for this file system user space: a file system management tool to create a tool: mkfs (make filesystem) mkfs-t type DEVICE mkfs. type DEVICE mkfs [Tab] [Tab] to view the file formats supported by mkfs. cramfs mkfs. ext3 mkfs. minix mkfs. btrfs mkfs. ext2 mkfs. ext4 mkfs. xfs ext file system dedicated management tools: mke2fs-t {ext2 | ext3 | ext4} DEVICE-B BLOCK: 1024,204 8, 4096 specify the BLOCK size; determine the block allocation size based on the size of the storage file-L 'label': Set the volume LABEL name-I #: to give more space to an inode-N #: how many inode-m are reserved for this disk partition #: the percentage of space occupied by the reserved disk space is used for later management.-c: Check disk errors. Only once-c is released, will perform a quick read Test-j: equivalent to mk2fs-t ext3; the original mke2fs is ext2, add journal to become ext3-O feature [,...] enable the specified feature has journal to enable the log function-O ^ feature [,...] disable the specified feature/etc/mke2fs. conf default feature configuration file blkid command: locate and display block device attributes locate/print block DEVICE attributes blkid device view LABEL, UUID, TYPE example:

# Check whether a new disk/dev/sdb is available [root @ localhost ~] # Fdisk-l Disk/dev/sda: 128.8 GB, 128849018880 bytes, 251658240 sectorsUnits = sectors of 1*512 = 512 bytesSector size (logical/physical ): 512 bytes/512 bytesI/O size (minimum/optimal): 512 bytes/512 bytesDisk label type: dosDisk identifier: 0x000c2314 Device Boot Start End Blocks Id System/dev/sda1 * 2048 411647 204800 83 Linux/dev/sda2 411648 41371647 20480000 83 Linux/dev/sda3 41371648 6 1851647 10240000 83 Linux/dev/sda4 61851648 251658239 94903296 5 Extended/dev/sda5 61855744 82335743 10240000 83 Linux/dev/sda6 82337792 86532095 2097152 82 Linux swap/Solaris/dev/sda7 61853696 61855743 1024 83 Linux/dev/sda8 86534144 107505663 10485760 83 LinuxPartition table entries are not in disk orderDisk/dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectorsUnits = sectors of 1*512 = 512 BytesSector size (logical/physical): 512 bytes/512 bytesI/O size (minimum/optimal): 512 bytes/512 bytes # create a new partition on the new disk [root @ localhost ~] # Fdisk/dev/sdbWelcome 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 tableBuilding a new DOS disklabel with disk identifier 0x3bb13419. command (m for help): n -------------------> Create a New Partition type: p primary (0 primary, 0 extended, 4 free) ----> select create primary Partition e ext Ended ---------------------------------> Select (default p): p -----------------------------------> Create primary Partition number (1-4, default 1): 1 First sector (2048-41943039, default 2048): -----> Select Start cylindrical default 2048 start Using default value 2048 Last sector, + sectors or + size {K, M, G} (2048-41943039, default 41943039 ): + 1024 MPartition 1 of type Linux and of size 1 GiB is setCommand (m for help): p ------------- ---------> Print partition table information # There are two ways to create the partition size above #1. Enter the start and end columns, determine the partition size #2 directly input + xx units to allocate the partition size Disk/dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectorsUnits = sectors of 1*512 = 512 bytesSector size (logical/physical): 512 bytes/512 bytesI/O size (minimum/optimal): 512 bytes/512 bytesDisk label type: dosDisk identifier: 0x3bb13419 Device Boot Start End Blocks Id System/dev/sdb1 2048 2099199 1048576 83 Li NuxCommand (m for help): nPartition type: p primary (1 primary, 0 extended, 3 free) e extendedSelect (default p ): e -------------------> Create an extended Partition (up to one extended Partition can be created) Partition number (2-4, default 2): 2 First sector (2099200-41943039, default 2099200 ): using default value 2099200 Last sector, + sectors or + size {K, M, G} (2099200-41943039, default 41943039): Using default value 41943039 Partition 2 of type Extended And of size 19 GiB is setCommand (m for help): nPartition type: p primary (1 primary, 1 extended, 2 free) l logical (numbered from 5) ---------> because the extended partition is created earlier, the logical partition Select (default p): lAdding logical partition 5 First sector (2101248-41943039, default 2101248) is available ): 512 Value out of range. first sector (2101248-41943039, default 2101248): Using default value 2101248 Last sector, + sectors or + size {K, M, G }( 2101248-41943039, default 41943039): + 512 MPartition 5 of type Linux and of size 512 MiB is setCommand (m for help): pDisk/dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectorsUnits = sectors of 1*512 = 512 bytesSector size (logical/physical): 512 bytes/512 bytesI/O size (minimum/optimal): 512 bytes/512 bytesDisk label type: dosDisk identifier: 0x3bb13419 Device Boot Start End Blocks Id Syst Em/dev/sdb1 2048 2099199 1048576 83 Linux/dev/sdb2 2099200 41943039 19921920 2101248 5 Extended/dev/sdb5 3149823 524288 83 LinuxCommand (m for help ): w # Do not save The input q and exit fdisk # Enter w to write The operation to The partition table has been altered! Calling ioctl () to re-read partition table. Syncing disks. # view partition information [root @ localhost ~] # Cat/proc/partitions major minor # blocks name 8 0 125829120 sda 8 1 204800 sda1 8 2 20480000 sda2 8 3 10240000 sda3 8 4 1 sda4 8 5 5 10240000 sda5 8 6 2097152 sda6 8 7 1024 sda7 8 8 10485760 sda8 8 16 20971520 sdb 8 17 1048576 sdb1 8 18 1 sdb2 8 21 524288 sdb5 11 0 651264 sr0 # reread partition information [root @ localhost ~] # Partx/dev/sdbNR start end sectors size name uuid 1 2048 2099199 2097152 1G 2 2099200 41943039 39843840 19G 5 2101248 3149823 1048576 512 M # disk formatting mkfs format the created sdb1 in xfs format [root @ localhost ~] # Mkfs-t xfs/dev/sdb1meta-data =/dev/sdb1 isize = 256 agcount = 4, agsize = 65536 blks = sectsz = 512 attr = 2, projid32bit = 1 = crc = 0 finobt = 0 data = bsize = 4096 blocks = 262144, imaxpct = 25 = sunit = 0 swidth = 0 blksnaming = version 2 bsize = 4096 ascii-ci = 0 ftype = 0log = internal log bsize = 4096 blocks = 2560, version = 2 = sectsz = 512 sunit = 0 blks, lazy-count = 1 realtime = none extsz = 4096 blocks = 0, rtextents = 0 # view the partition format [root @ loc Alhost ~] # Blkid/dev/sdb1/dev/sdb1: UUID = "a7712c0d-6264-496e-8f6b-1da5b7da5939" TYPE = "xfs" # format/dev/sdb5 as ext4 using mkfs. ext4 DEVICE [root @ localhost ~] # Mkfs. ext4/dev/sdb5mke2fs 1.42.9 (28-Dec-2013) Filesystem label = OS type: LinuxBlock size = 4096 (log = 2) Fragment size = 4096 (log = 2) Stride = 0 blocks, stripe width = 0 blocks32768 inodes, 131072 blocks6553 blocks (5.00%) reserved for the super userFirst data block = 0 Maximum filesystem blocks = 1342177284 block groups32768 blocks per group, 32768 fragments per group8192 inodes per groupSuperblock backups store D on blocks: 32768,983 04 Allocating group tables: done Writing inode tables: done Creating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: done # view the partition format [root @ localhost ~] # Blkid/dev/sdb5/dev/sdb5: UUID = "7ff064f9-49c8-466d-8d86-7f4eba5e353b" TYPE = "ext4" # ext file system dedicated management tools to create partitions [root @ localhost ~] # Mke2fs-t ext4-L 'test _ mk2fs '/dev/sdb6mke2fs 1.42.9 (28-Dec-2013) Filesystem label = test_mk2fsOS type: LinuxBlock size = 4096 (log = 2) fragment size = 4096 (log = 2) Stride = 0 blocks, Stripe width = 0 blocks32768 inodes, 131072 blocks6553 blocks (5.00%) reserved for the super userFirst data block = 0 Maximum filesystem blocks = 1342177284 block groups32768 blocks per group, 32768 fragments per group8192 inodes per groupSuperblock backups stored on blocks: 32768,983 04 Allocating group tables: done Writing inode tables: done Creating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: done