Linux第七周

wuliws

　　1、创建一个10G分区，并格式为ext4文件系统；
　　(1) 要求其block大小为2048, 预留空间百分比为2, 卷标为MYDATA, 默认挂载属性包含acl；
　　(2) 挂载至/data/mydata目录，要求挂载时禁止程序自动运行，且不更新文件的访问时间戳；
[root@localhost ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xa0b19c72.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-10443, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-10443, default 10443): +10G
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@localhost ~]# partx -a /dev/sdb
BLKPG: Device or resource busy
error adding partition 1
[root@localhost ~]# cat /proc/partitions
major minor  #blocks  name
   8        0  125829120 sda
   8        1     512000 sda1
   8        2    2048000 sda2
   8        3  123268096 sda3
   8       16   83886080 sdb
   8       17   10490413 sdb1
[root@localhost ~]# mke2fs -t ext4 -b 2048 -m 2 -L 'MYDATA'  /dev/sdb1               
mke2fs 1.41.12 (17-May-2010)
文件系统标签=MYDATA
操作系统:Linux
块大小=2048 (log=1)
分块大小=2048 (log=1)
Stride=0 blocks, Stripe width=0 blocks
657408 inodes, 5245206 blocks
104904 blocks (2.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=543162368
321 block groups
16384 blocks per group, 16384 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
        16384, 49152, 81920, 114688, 147456, 409600, 442368, 802816, 1327104,
        2048000, 3981312
正在写入inode表: 完成                           
Creating journal (32768 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
This filesystem will be automatically checked every 29 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
[root@localhost ~]# mkdir -p /data/mydata
[root@localhost ~]# echo 'LABEL=MYDATA  /data/mydata  ext4  defaults,acl  0 0' >> /etc/fstab
[root@localhost ~]# mount -a　　2、创建一个大小为1G的swap分区，并创建好文件系统，并启用之；
[root@localhost ~]# fdisk /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (6529-10443, default 6529):
Using default value 6529
Last cylinder, +cylinders or +size{K,M,G} (6529-10443, default 10443): +1G
Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 82
Changed system type of partition 2 to 82 (Linux swap / Solaris)
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: 设备或资源忙.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@localhost ~]# partx -a /dev/sdb
BLKPG: Device or resource busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
[root@localhost ~]# mkswap /dev/sdb2
Setting up swapspace version 1, size = 1060284 KiB
no label, UUID=54ef09ac-5e9e-4453-9269-84936c6c1c19
[root@localhost ~]# swapon /dev/sdb2　　3、写一个脚本
　　   (1)、获取并列出当前系统上的所有磁盘设备；
　　   (2)、显示每个磁盘设备上每个分区相关的空间使用信息；
[root@localhost tmp]# cat t3.sh
#!/bin/bash
#
i=1
fdisk -l /dev/[s,h]d[a-z] | grep "Disk /"
for DevName in $(ls /dev/[s,h]d[a-z][1-9]);do         
     if [ $i -eq 1 ] ;then
         df -h $DevName | awk -v OFS="    " '{print $1,$2,$3,$4,$5,$6}'
         let i++
     else
         df -h $DevName | grep -v "File" | awk -v OFS="    " -v name=$DevName '{print name,$2,$3,$4,$5,$6}'
     fi
done　　4、总结RAID的各个级别及其组合方式和性能的不同；
　　

RAID级别	RAID0	RAID1	RAID5	RAID6	RAID10	RAID01
容错	无	有	有	有	有	有
冗余	无	镜像	奇偶校验	奇偶校验	镜像	镜像
读性能	有所提高	有所提高	有所提高	有所提高	有所提高	有所提高
写性能	有所提高	略有下降	有所提高	有所提高	有所提高	有所提高
最少磁盘数	2,2+	2,2+	3，3+	4，4+	4，4+	4，4+
允许磁盘最多损坏数	0	1	1	2	每组1个	每组1个
可用容量	N*min(s1,s2,...)	N*min(s1,s2,...)/2	(N-1)*min(s1,s2,...)	(N-2)*min(s1,s2,...)	N*min(s1,s2,...)/2	N*min(s1,s2,...)/2

　　

　　5、创建一个大小为10G的RAID1，要求有一个空闲盘，而且CHUNK大小为128k;
[root@localhost ~]# fdisk  /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x75d40809.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-10443, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-10443, default 10443): +10G
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (1307-10443, default 1307):
Using default value 1307
Last cylinder, +cylinders or +size{K,M,G} (1307-10443, default 10443): +10G
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (2613-10443, default 2613):
Using default value 2613
Last cylinder, +cylinders or +size{K,M,G} (2613-10443, default 10443): +10G
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@localhost ~]# partx -a /dev/sdb
BLKPG: Device or resource busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
BLKPG: Device or resource busy
error adding partition 3
[root@localhost ~]# cat /proc/partitions
major minor  #blocks  name
   8        0  125829120 sda
   8        1     512000 sda1
   8        2    2048000 sda2
   8        3  123268096 sda3
   8       16   83886080 sdb
   8       17   10490413 sdb1
   8       18   10490445 sdb2
   8       19   10490445 sdb3
[root@localhost ~]# mdadm -C /dev/md0 -n 2 -l 1 -c 128 -x 1 /dev/sdb{1,2,3}
mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
[root@localhost ~]# mdadm -D /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Mon Aug  1 20:19:54 2016
     Raid Level : raid1
     Array Size : 10482176 (10.00 GiB 10.73 GB)
  Used Dev Size : 10482176 (10.00 GiB 10.73 GB)
   Raid Devices : 2
  Total Devices : 3
    Persistence : Superblock is persistent
    Update Time : Mon Aug  1 20:20:40 2016
          State : clean, resyncing
Active Devices : 2
Working Devices : 3
Failed Devices : 0
  Spare Devices : 1
  Resync Status : 87% complete
           Name : localhost.localdomain:0  (local to host localhost.localdomain)
           UUID : 2277076e:bc9b6d70:eabfb522:cee50958
         Events : 14
    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       18        1      active sync   /dev/sdb2
       2       8       19        -      spare   /dev/sdb3　　6、创建一个大小为4G的RAID5设备，chunk大小为256k，格式化ext4文件系统，要求可开机自动挂载至/backup目录，而且不更新访问时间戳，且支持acl功能；
[root@localhost ~]# fdisk /dev/sdb
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-10443, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-10443, default 10443): +4G
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (524-10443, default 524):
Using default value 524
Last cylinder, +cylinders or +size{K,M,G} (524-10443, default 10443): +4G
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (1047-10443, default 1047):
Using default value 1047
Last cylinder, +cylinders or +size{K,M,G} (1047-10443, default 10443): +10G
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@localhost ~]# mdadm -C /dev/md5 -n 3 -l 5 -c 256 /dev/sdb{1,2,3}
mdadm: /dev/sdb1 appears to be part of a raid array:
       level=raid1 devices=2 ctime=Mon Aug  1 20:19:54 2016
mdadm: largest drive (/dev/sdb3) exceeds size (4196864K) by more than 1%
Continue creating array?
Continue creating array? (y/n) y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md5 started.
[root@localhost ~]# mdadm -D /dev/md5
/dev/md5:
        Version : 1.2
  Creation Time : Mon Aug  1 20:35:52 2016
     Raid Level : raid5
     Array Size : 8393728 (8.00 GiB 8.60 GB)
  Used Dev Size : 4196864 (4.00 GiB 4.30 GB)
   Raid Devices : 3
  Total Devices : 3
    Persistence : Superblock is persistent
    Update Time : Mon Aug  1 20:36:12 2016
          State : clean, degraded, recovering
Active Devices : 2
Working Devices : 3
Failed Devices : 0
  Spare Devices : 1
         Layout : left-symmetric
     Chunk Size : 256K
Rebuild Status : 8% complete
           Name : localhost.localdomain:5  (local to host localhost.localdomain)
           UUID : 8d09334e:eb6c0810:f773a7f9:2030c941
         Events : 2
    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       18        1      active sync   /dev/sdb2
       3       8       19        2      spare rebuilding   /dev/sdb3
[root@localhost ~]# mkfs.ext4 /dev/md5
[root@localhost ~]# mkdir /backup
[root@localhost ~]# echo "/dev/md5    /backup   ext4  defaults,acl,nodiratime  0 0"  >> /etc/fstab　　7、写一个脚本

　　   (1) 接受一个以上文件路径作为参数；
　　   (2) 显示每个文件拥有的行数；
　　   (3) 总结说明本次共为几个文件统计了其行数；
[root@localhost tmp]# cat test7.sh
#!/bin/bash
if [ $# -eq 0 ];then
        echo "Please give a file name !"
        exit 1
fi
for i in $*
do
        echo "$i have $(wc -l $i | cut -d' ' -f1) lines"
done
echo  "本次共为$#个文件统计了其行数!"　　8、写一个脚本
　　   (1) 传递两个以上字符串当作用户名；
　　   (2) 创建这些用户；且密码同用户名；
　　   (3) 总结说明共创建了几个用户；
#!/bin/bash
if [ $# -lt 2 ];then
        echo "At least give two username !"
        exit 1
fi
for i in $*
do
        useradd $i
        echo "$i:$i" | chpasswd
done
echo "Total Add $# users !"　　9、写一个脚本，新建20个用户，visitor1-visitor20；计算他们的ID之和；

[root@localhost tmp]# cat test9.sh
#!/bin/bash
declare -i tid
for i in {1..20}
do
        useradd visitor$i
        let tid+=$(id -u visitor$i)
done
echo "Total id is $tid !"　　10、写一脚本，分别统计/etc/rc.d/rc.sysinit、/etc/rc.d/init.d/functions和/etc/fstab文件中以#号开头的行数之和，以及总的空白行数；
[root@localhost tmp]# cat test10.sh
#!/bin/bash
declare -i l1
declare -i space
for i in /etc/{rc.d/{rc.sysinit,init.d/functions},fstab}
do
        let l1+=$(grep '^#' $i | wc -l | cut -d' ' -f1)
        let space+=$(grep  '^[[:space:]]*$' $i | wc -l | cut -d' ' -f1)
done
echo "Comment lines beginning with a '#' total $l1 lines  !"
echo "Blank lines total $space lines !"　　11、写一个脚本，显示当前系统上所有默认shell为bash的用户的用户名、UID以及此类所有用户的UID之和；
[root@localhost tmp]# cat test11.sh
#!/bin/bash
declare -i uid
for i in $(grep bash$ /etc/passwd | cut -d: -f1)
do
        echo "$i, `id -u $i`"
        let uid+=`id -u $i`
done
echo "Total uid is $uid !"　　12、写一个脚本，显示当前系统上所有，拥有附加组的用户的用户名；并说明共有多少个此类用户；
#!/bin/bash
awk '{FS=":"} $3 != $4 {print $1;n++}END{ print n}' /etc/passwd　　13、创建一个由至少两个物理卷组成的大小为20G的卷组；要求，PE大小为8M；而在卷组中创建一个大小为5G的逻辑卷mylv1，格式化为ext4文件系统，开机自动挂载至/users目录，支持acl；

　　

　　[root@localhost ~]# fdisk /dev/sdb
　　Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
　　Building a new DOS disklabel with disk identifier 0xdb484fda.
　　Changes will remain in memory only, until you decide to write them.
　　After that, of course, the previous content won't be recoverable.
　　

　　Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
　　

　　WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
　　switch off the mode (command 'c') and change display units to
　　sectors (command 'u').
　　

　　Command (m for help): n
　　Command action
　　e   extended
　　p   primary partition (1-4)
　　p
　　Partition number (1-4): 1
　　First cylinder (1-1305, default 1):
　　Using default value 1
　　Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305):
　　Using default value 1305
　　

　　Command (m for help): w
　　The partition table has been altered!
　　

　　Calling ioctl() to re-read partition table.
　　Syncing disks.
　　[root@localhost ~]# fdisk /dev/sdc
　　Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
　　Building a new DOS disklabel with disk identifier 0xcbb0c025.
　　Changes will remain in memory only, until you decide to write them.
　　After that, of course, the previous content won't be recoverable.
　　

　　Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
　　

　　WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
　　switch off the mode (command 'c') and change display units to
　　sectors (command 'u').
　　

　　Command (m for help): n
　　Command action
　　e   extended
　　p   primary partition (1-4)
　　p
　　Partition number (1-4): 1
　　First cylinder (1-1305, default 1):
　　Using default value 1
　　Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305):
　　Using default value 1305
　　

　　Command (m for help): w
　　The partition table has been altered!
　　

　　Calling ioctl() to re-read partition table.
　　Syncing disks.
　　[root@localhost ~]# pvcreate /dev/sd{b,c}1
　　Physical volume "/dev/sdb1" successfully created
　　Physical volume "/dev/sdc1" successfully created
　　[root@localhost ~]# vgcreate -s 8m myvg /dev/sd{b,c}1
　　Volume group "myvg" successfully created
　　[root@localhost ~]# lvcreate -L 5g -n mlv1 myvg
　　Logical volume "mlv1" created
　　[root@localhost ~]# mkfs.ext4 /dev/myvg/mlv1
　　[root@localhost ~]# echo "/dev/myvg/mlv1  /users  ext4  defaults,acl 0 0" >> /etc/fstab

　　[root@localhost ~]# vgdisplay
　　--- Volume group ---
　　VG Name               myvg
　　System ID
　　Format                lvm2
　　Metadata Areas        2
　　Metadata Sequence No  2
　　VG Access             read/write
　　VG Status             resizable
　　MAX LV                0
　　Cur LV                1
　　Open LV               1
　　Max PV                0
　　Cur PV                2
　　Act PV                2
　　VG Size               19.98 GiB
　　PE Size               8.00 MiB
　　Total PE              2558
　　Alloc PE / Size       640 / 5.00 GiB
　　Free  PE / Size       1918 / 14.98 GiB
　　VG UUID               Yrb5ku-mOoE-cdk3-E0QW-QmyY-hM39-BRGBjk
　　[root@localhost ~]# lvdisplay
　　--- Logical volume ---
　　LV Path                /dev/myvg/mlv1
　　LV Name                mlv1
　　VG Name                myvg
　　LV UUID                oqYvWw-FpYI-Ccd4-KWRG-V2Dq-pcNS-apoGJ6
　　LV Write Access        read/write
　　LV Creation host, time localhost.localdomain, 2016-08-02 22:23:21 +0800
　　LV Status              available
　　# open                 1
　　LV Size                5.00 GiB
　　Current LE             640
　　Segments               1
　　Allocation             inherit
　　Read ahead sectors     auto
　　- currently set to     256
　　Block device           253:0
　　14、新建用户magedu；其家目录为/users/magedu，而后su切换至此用户，复制多个文件至家目录；
[root@localhost ~]# useradd -d /users/magedu magedu
[root@localhost ~]# echo magedu:123456 | chpasswd
[root@localhost ~]# su - magedu
[magedu@localhost ~]$ pwd
/users/magedu
[magedu@localhost ~]$ cp /etc/{passwd,group} .
[magedu@localhost ~]$ ls
group  passwd　　15、扩展mylv1至9G，确保扩展完成后原有数据完全可用；
[root@localhost ~]# lvextend -L 9G /dev/myvg/mlv1
  Size of logical volume myvg/mlv1 changed from 5.00 GiB (640 extents) to 9.00 GiB (1152 extents).
  Logical volume mlv1 successfully resized
[root@localhost ~]# resize2fs /dev/myvg/mlv1
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/myvg/mlv1 is mounted on /users; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 1
Performing an on-line resize of /dev/myvg/mlv1 to 2359296 (4k) blocks.
The filesystem on /dev/myvg/mlv1 is now 2359296 blocks long.
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/myvg/mlv1
  LV Name                mlv1
  VG Name                myvg
  LV UUID                oqYvWw-FpYI-Ccd4-KWRG-V2Dq-pcNS-apoGJ6
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2016-08-02 22:23:21 +0800
  LV Status              available
  # open                 1
  LV Size                9.00 GiB
  Current LE             1152
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
[root@localhost ~]# ls /users/magedu/
group  passwd　　16、缩减mylv1至7G，确保缩减完成后原有数据完全可用；
[root@localhost ~]# lvreduce -L 7G /dev/myvg/mlv1
  WARNING: Reducing active and open logical volume to 7.00 GiB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce mlv1? [y/n]: y
  Size of logical volume myvg/mlv1 changed from 9.00 GiB (1152 extents) to 7.00 GiB (896 extents).
  Logical volume mlv1 successfully resized
[root@localhost ~]# resize2fs /dev/myvg/mlv1
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/myvg/mlv1 is mounted on /users; on-line resizing required
On-line shrinking from 2359296 to 1835008 not supported.
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/myvg/mlv1
  LV Name                mlv1
  VG Name                myvg
  LV UUID                oqYvWw-FpYI-Ccd4-KWRG-V2Dq-pcNS-apoGJ6
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2016-08-02 22:23:21 +0800
  LV Status              available
  # open                 1
  LV Size                7.00 GiB
  Current LE             896
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
[root@localhost ~]# ls /users/magedu/
group  passwd　　17、对mylv1创建快照，并通过备份数据；要求保留原有的属主属组等信息；
[root@localhost ~]# lvcreate -L 5G -p r -s -n mylv1_snapshot /dev/myvg/mlv1  
  Logical volume "mylv1_snapshot" created