[root@cobbler-node1 ~]# dd if=/dev/zero of=/tmp/swap bs=10M count=100 100+0 records in 100+0 records out 1048576000 bytes (1.0 GB) copied, 31.7965 s, 33.0 MB/s [root@cobbler-node1 ~]# ls -ldh /tmp/swap -rw-r--r-- 1 root root 1000M Jun 23 15:05 /tmp/swap [root@cobbler-node1 ~]# mkswap /tmp/swap mkswap: /tmp/swap: warning: don't erase bootbits sectors on whole disk. Use -f to force. Setting up swapspace version 1, size = 1023996 KiB no label, UUID=ea3fe1f1-895c-4885-9e42-78cab304efd1 [root@cobbler-node1 ~]# free -m total used free shared buffers cached Mem: 474 457 17 0 2 390 -/+ buffers/cache: 64 410 Swap: 2047 0 2047 [root@cobbler-node1 ~]# swapon /tmp/swap [root@cobbler-node1 ~]# free -m total used free shared buffers cached Mem: 474 458 16 0 2 390 -/+ buffers/cache: 65 409 Swap: 3047 0 3047 [root@cobbler-node1 ~]# echo "/tmp/swap swap swap defaults 0 0" >> /etc/fstab #显示正在使用的虚拟交换空间 [root@cobbler-node1 ~]# swapon -s Filename Type Size Used Priority /dev/sda2 partition 1048568 0 -1 /dev/sdb1 partition 1048568 0 -2 /tmp/swap file 1023992 0 -3 企业案例场景： Swap在工作中，特别是java环境，程序写的有问题，会发生内存泄露，可能会被占用，让开发改程序，临时运维加大swap，重启系统
7 磁盘格式化挂载 7.1 磁盘格式化并挂载的操作步骤#普通ext4文件系统格式化过程 [root@cobbler-node1 ~]# mkfs -t ext4 -b 4096 -I 256 /dev/sdb3 mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 24320 inodes, 24320 blocks 1216 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=25165824 1 block group 32768 blocks per group, 32768 fragments per group 24320 inodes per group Writing inode tables: done Creating journal (1024 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 24 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. #防止出现上面的告警信息（标黄） [root@cobbler-node1 ~]# tune2fs -c -1 /dev/sdb3 tune2fs 1.41.12 (17-May-2010) Setting maximal mount count to -1 #挂载到相应目录 [root@cobbler-node1 ~]# mount -t ext4 /dev/sdb3 /applog1 #显示挂载的文件系统 [root@cobbler-node1 ~]# df -hT Filesystem Type Size Used Avail Use% Mounted on /dev/sda3 ext4 8.7G 3.3G 5.1G 40% / tmpfs tmpfs 238M 0 238M 0% /dev/shm /dev/sda1 ext4 194M 29M 155M 16% /boot /dev/sr0 iso9660 4.2G 4.2G 0 100% /mnt /dev/sdb3 ext4 90M 4.1M 81M 5% /applog1
7.2 dumpe2fs查看文件系统内部详细信息
# dumpe2fs - dump ext2/ext3/ext4 filesystem information
[root@cobbler-node1 ~]# dumpe2fs /dev/sdb3
dumpe2fs 1.41.12 (17-May-2010)
Filesystem volume name: <none>
Last mounted on:
<not available>
Filesystem UUID:
23d188bf-7b4c-41c1-a33e-dd908926303f
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features:
has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg
dir_nlink extra_isize
Filesystem flags:
signed_directory_hash
Default mount options: (none)
Filesystem state:
clean
Errors behavior:
Continue
Filesystem OS type:
Linux
Inode count:
24320
Block count:
24320
Reserved block count:
1216
Free blocks:
21761
Free inodes:
24309
First block:
0
Block size:
4096
Fragment size:
4096
Reserved GDT blocks:
5
Blocks per group:
32768
Fragments per group:
32768
Inodes per group:
24320
Inode blocks per group: 1520
Flex block group size: 16
Filesystem created:
Sun Jun 24 15:01:18 2018
Last mount time:
Sun Jun 24 15:05:39 2018
Last write time:
Sun Jun 24 15:05:39 2018
Mount count:
1
Maximum mount count:
-1
Last checked:
Sun Jun 24 15:01:18 2018
Check interval:
15552000 (6 months)
Next check after:
Fri Dec 21 15:01:18 2018
Lifetime writes:
10 MB
Reserved blocks uid:
0 (user root)
Reserved blocks gid:
0 (group root)
First inode:
11
Inode size:
256
Required extra isize:
28
Desired extra isize:
28
Journal inode:
8
Default directory hash: half_md4
Directory Hash Seed:
89578f2c-49a6-4023-af1d-bd055875100f
Journal backup:
inode blocks
Journal features:
(none)
Journal size:
4096k
Journal length:
1024
Journal sequence:
0x00000001
Journal start:
0
Group 0: (Blocks 0-24319) [ITABLE_ZEROED]
Checksum 0xeec2, unused inodes 24309
Primary superblock at 0, Group descriptors at 1-1
Reserved GDT blocks at 2-6
Block bitmap at 7 (+7), Inode bitmap at 23 (+23)
Inode table at 39-1558 (+39)
21761 free blocks, 24309 free inodes, 2 directories, 24309 unused inodes
Free blocks: 2559-24319
Free inodes: 12-24320
Linux公社的RSS地址：https://www.linuxidc.com/rssFeed.aspx