Day22 课堂笔记
2）parted 命令
案例1：需求：RAID5大小6T，已经装了系统了， 额外添加4块2T盘
现有一个做了RAID5的硬盘，要求分三个区，
硬盘总分区大小： 6.2T
/data0 4.8T
/data1 1T
4G （无需格式化，作DRBD+Hearbeat+MySQL高可用集群）
parted /dev/sdb mklabel gpt #<==修改分区格式为gpt。
parted /dev/sdb mkpart primary 0 4800000 #<==创建一个4.8T主分区
parted /dev/sdb mkpart primary 4800001 5800001 #<==创建一个1T主分区
parted /dev/sdb mkpart primary 5800002 5804098 #<==创建一个4G主分区
parted /dev/sdb p
实践如下：
[root@oldboyedu ~]# parted /dev/sdb
GNU Parted 3.1
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
============================================================
********查看的帮助********
============================================================
(parted) help
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
resizepart NUMBER END resize partition NUMBER
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
============================================================
********创建gpt格式的分区表********
============================================================
(parted) mklabel gpt
============================================================
********查看的结果********
============================================================
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
============================================================
********创建第1个主分区********
============================================================
(parted) mkpart primary 0 10
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? I <--> 忽略提示
============================================================
********查看的结果********
============================================================
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 10.0MB 9983kB primary
============================================================
********创建第2个主分区********
============================================================
(parted) mkpart primary 11 20
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? I
============================================================
********查看的结果********
============================================================
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 10.0MB 9983kB primary
2 11.0MB 20.0MB 9000kB primary
============================================================
********创建第3个主分区********
============================================================
(parted) mkpart primary 21 30
============================================================
********查看的结果********
============================================================
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 10.0MB 9983kB primary
2 11.0MB 20.0MB 9000kB primary
3 21.0MB 30.4MB 9437kB primary
============================================================
********创建第4个逻辑分区********
============================================================
(parted) mkpart logic 31 40
============================================================
********查看的结果********
============================================================
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 10.0MB 9983kB primary
2 11.0MB 20.0MB 9000kB primary
3 21.0MB 30.4MB 9437kB primary
4 31.5MB 39.8MB 8389kB logic
============================================================
********删除第4个逻辑分区********
============================================================
(parted) rm 4
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 537MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 10.0MB 9983kB primary
2 11.0MB 20.0MB 9000kB primary
3 21.0MB 30.4MB 9437kB primary
============================================================
********保存并退出********
============================================================
(parted) q
Information: You may need to update /etc/fstab.
============================================================
********查看的结果********
============================================================
[root@oldboyedu ~]# ll /dev/sdb*
brw-rw---- 1 root disk 8, 16 Mar 31 15:56 /dev/sdb
brw-rw---- 1 root disk 8, 17 Mar 31 15:56 /dev/sdb1
brw-rw---- 1 root disk 8, 18 Mar 31 15:56 /dev/sdb2
brw-rw---- 1 root disk 8, 19 Mar 31 15:56 /dev/sdb3
案例2：需求：刚买的服务器 4块2T 刚买，要做RAID5，装系统怎么搞定？
方法1：Raid里可以支持RAID5后，6T，允许你把6T分成虚拟磁盘。
200G分成第一个虚拟磁盘剩下不分留着装系统后（parted）。方法2：装系统过程中有这个功能，系统镜像支持GPT格式分区，很隐蔽。
方法3：引导工具，进入然后用parted分区。
1. 文件系统
1.1、什么是文件系统？
计算机存储和组织数据的方法或者机制。落地是一个软件。
1.2、为什么需要文件系统？
磁盘、物理介质、磁粒子物理元素。 硬件需要软件驱动使用，磁盘需要文件系统驱动。
文件系统实现通过磁盘管理规划、存取数据。
1.3、文件系统有哪些种类？
- Windows:NTFS、fat32、msdos
- Linux:ext2、ext3(C5)、ext4(C6)、Xfs（C7）、btrfs
1.4、创建文件系统实践。
1）mkfs 命令
格式化ext4文件系统 mkfs.ext4
[root@oldboyedu ~]# mkfs -t ext4 /dev/sdb1
==========================================================
*****其实关键就是生成一定数量的Inode和Block*****
==========================================================
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
25688 inodes, 102400 blocks
5120 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=33685504
13 block groups
8192 blocks per group, 8192 fragments per group
1976 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
查看mkfs参数（CentOS7man是查不到的，把参数写错即可）
[root@oldboyedu ~]# mkfs --abc
mkfs.ext2: invalid option -- '-' <-->显示无效的参数，然后就出来参数了
Usage: mkfs.ext2 [-c|-l filename] [-b block-size] [-C cluster-size]
[-i bytes-per-inode] [-I inode-size] [-J journal-options]
[-G flex-group-size] [-N number-of-inodes]
[-m reserved-blocks-percentage] [-o creator-os]
[-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
[-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
[-t fs-type] [-T usage-type ] [-U UUID] [-jnqvDFKSV] device [blocks-count]
指定块大小和inode大小格式
[root@oldboyedu ~]# mkfs -t ext4 -b 4096 -I 512 /dev/sdb3
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
38400 inodes, 38400 blocks
1920 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=39845888
2 block groups
32768 blocks per group, 32768 fragments per group
19200 inodes per group
Superblock backups stored on blocks:
32768
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
[root@oldboyedu ~]# dumpe2fs /dev/sdb3|egrep -i "size"
dumpe2fs 1.42.9 (28-Dec-2013)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Block size: 4096
Fragment size: 4096
Group descriptor size: 64
Flex block group size: 16
Inode size: 512
Required extra isize: 28
Desired extra isize: 28
Journal size: 16M
2）mount 命令
[root@oldboyedu ~]# mount /dev/sdb1 /mnt #临时挂载到/mnt
[root@oldboyedu ~]# df -h #查看挂载结果
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 19G 1.9G 18G 10% /
devtmpfs 980M 5.0M 975M 1% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 18M 973M 2% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 253M 136M 118M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
tmpfs 199M 0 199M 0% /run/user/1000
/dev/sdb1 93M 1.6M 85M 2% /mnt #<====已挂载。
[root@oldboyedu ~]# cat /proc/mounts #查看挂载结果
rootfs / rootfs rw 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
configfs /sys/kernel/config configfs rw,relatime 0 0
/dev/sda3 / xfs rw,relatime,attr2,inode64,noquota 0 0
systemd-1 /proc/sys/fs/binfmt_misc autofs rw,relatime,fd=32,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=19277 0 0
hugetlbfs /dev/hugepages hugetlbfs rw,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
mqueue /dev/mqueue mqueue rw,relatime 0 0
/dev/sda1 /boot xfs rw,relatime,attr2,inode64,noquota 0 0
tmpfs /run/user/0 tmpfs rw,nosuid,nodev,relatime,size=202812k,mode=700 0 0
tmpfs /run/user/1000 tmpfs rw,nosuid,nodev,relatime,size=202812k,mode=700,uid=1000,gid=1000 0 0
/dev/sdb1 /mnt ext4 rw,relatime,data=ordered 0 0 #<==已挂载。
[root@oldboyedu ~]# touch /mnt/oldboy #<==测试。
[root@oldboyedu ~]# ls /mnt
lost+found oldboy
挂载的分区需格式化
[root@oldboyedu ~]# mount /dev/sdb2 /opt #没有格式化没法挂载
mount: /dev/sdb2 is write-protected, mounting read-only
mount: unknown filesystem type '(null)'
[root@oldboyedu ~]# mkfs.xfs /dev/sdb2 #格式化xfs文件系统
meta-data=/dev/sdb2 isize=512 agcount=4, agsize=6400 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=25600, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=855, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@oldboyedu ~]# mount -t xfs /dev/sdb2 /opt
[root@oldboyedu ~]# df -h|grep opt
/dev/sdb2 97M 5.3M 92M 6% /opt
[root@oldboyedu ~]# touch /opt/oldgirl
[root@oldboyedu ~]# ls /opt
oldgirl
如何开机自动挂载？编辑/etc/fstab ，实现开机自动挂载
[root@oldboyedu ~]# cat /etc/fstab
UUID=3a3a295f-88f8-456d-94dc-1a3eeb517c02 / xfs defaults 0 0
UUID=fd2e0ca7-32be-425f-86a2-85c02b9ec5ea /boot xfs defaults 0 0
UUID=79a3924b-739e-48dc-ab0c-0444b9ac6591 swap swap defaults 0 0
设备 挂载点 文件系统类型 默认挂载选项 是否备份 是否开机磁盘检查
/dev/sdb2 /opt xfs defaults 0 0
2）umount 命令
[root@oldboyedu /mnt]# umount /mnt
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@oldboyedu /mnt]# pwd
/mnt
You have new mail in /var/spool/mail/root
[root@oldboyedu /mnt]# umount -lf /mnt #<==强制卸载
[root@oldboyedu /mnt]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 19G 1.9G 18G 10% /
devtmpfs 980M 5.0M 975M 1% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 18M 973M 2% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 253M 136M 118M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
tmpfs 199M 0 199M 0% /run/user/1000
3）blkid 命令
[root@oldboyedu ~]# blkid
/dev/sdb1: UUID="a45b004f-2322-4dc4-a281-2a212dd2ab79" TYPE="ext4"
/dev/sdb2: UUID="7daf8142-b641-4b60-a287-4e08dfa18611" TYPE="xfs"
/dev/sda1: UUID="fd2e0ca7-32be-425f-86a2-85c02b9ec5ea" TYPE="xfs"
/dev/sda2: UUID="79a3924b-739e-48dc-ab0c-0444b9ac6591" TYPE="swap"
/dev/sda3: UUID="3a3a295f-88f8-456d-94dc-1a3eeb517c02" TYPE="xfs"
4）fsck命令
- 正常的磁盘不能操作。
- 卸载挂载点在操作
- 只能修复ext文件系统
[root@oldboyedu ~]# fsck -a /dev/sdb1
fsck from util-linux 2.23.2
/dev/sdb1: clean, 12/25688 files, 8896/102400 blocks
[root@oldboyedu ~]# mount /dev/sdb1 /mnt
[root@oldboyedu ~]# fsck -a /dev/sdb1
fsck from util-linux 2.23.2
/dev/sdb1 is mounted.
e2fsck: Cannot continue, aborting.
[root@oldboyedu ~]# e2fsck /dev/sdb1
e2fsck 1.42.9 (28-Dec-2013)
/dev/sdb1: clean, 12/25688 files, 8896/102400 blocks
[root@oldboyedu ~]# fsck -a /dev/sdb1
fsck from util-linux 2.23.2
/dev/sdb1: clean, 12/25688 files, 8896/102400 blocks
[root@oldboyedu ~]# xfs_repair /dev/sdb2
xfs_repair: /dev/sdb2 contains a mounted filesystem
xfs_repair: /dev/sdb2 contains a mounted and writable filesystem
fatal error -- couldn't initialize XFS library
[root@oldboyedu ~]# umount /opt
[root@oldboyedu ~]# xfs_repair /dev/sdb2
Phase 1 - find and verify superblock...
Phase 2 - using internal log
- zero log...
- scan filesystem freespace and inode maps...
- found root inode chunk
Phase 3 - for each AG...
- scan and clear agi unlinked lists...
- process known inodes and perform inode discovery...
- agno = 0
- agno = 1
- agno = 2
- agno = 3
- process newly discovered inodes...
Phase 4 - check for duplicate blocks...
- setting up duplicate extent list...
- check for inodes claiming duplicate blocks...
- agno = 0
- agno = 1
- agno = 2
- agno = 3
Phase 5 - rebuild AG headers and trees...
- reset superblock...
Phase 6 - check inode connectivity...
- resetting contents of realtime bitmap and summary inodes
- traversing filesystem ...
- traversal finished ...
- moving disconnected inodes to lost+found ...
Phase 7 - verify and correct link counts...
done
5）dd 命令
dd if=/dev/sda of=/dev/sdc bs=512 count=10240
来源 生成文件系统 block大小 块个数
swap作用，内存不够时候，用来充当内存，一般内存1.5倍。大于8G给8G
将来JAVA服务，内存泄漏
swap就会占用，操作系统性能下降
案例：增加swap分区 100M
============================================================
******查看swap情况*****
============================================================
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 972 135 699 7 137 682
Swap: 767 0 767
============================================================
******创建100M虚拟磁盘*****
============================================================
[root@oldboyedu ~]# dd if=/dev/zero of=/tmp/100M bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB) copied, 4.09005 s, 25.6 MB/s
============================================================
******格式化100M虚拟磁盘*****
============================================================
[root@oldboyedu ~]# mkswap /tmp/100M
Setting up swapspace version 1, size = 102396 KiB
no label, UUID=ad35b6b9-dfbe-436f-9322-ac0a2019387e
============================================================
******挂载100M虚拟磁盘*****
============================================================
[root@oldboyedu ~]# swapon /tmp/100M
swapon: /tmp/100M: insecure permissions 0644, 0600 suggested.
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 972 135 596 7 240 667
Swap: 867 0 867
============================================================
******卸载100M虚拟磁盘*****
============================================================
[root@oldboyedu ~]# swapoff /tmp/100M
[root@oldboyedu ~]# free -m
total used free shared buff/cache available
Mem: 972 135 596 7 240 667
查看文件系统内部细节：
1）ext文件系统
[root@oldboyedu ~]# dumpe2fs /dev/sdb1|egrep -i "size"
dumpe2fs 1.42.9 (28-Dec-2013)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
Block size: 1024
Fragment size: 1024
Group descriptor size: 64
Flex block group size: 16
Inode size: 128
Journal size: 4096k
2）xfs文件系统
[root@oldboyedu ~]# xfs_info /dev/sda1
meta-data=/dev/sda1 isize=512 agcount=4, agsize=16384 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=65536, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=855, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0