Linux file system swap swap partition and DD command details (3)

Linux file system swap swap partition and DD command details (3)

1. Create swap partition: Partition type 82 is equivalent to virtual memory in Windows

Mkswap/dev/sda5 creating a Swap partition file system region

-L label create label for swap partition

SWAPON/DEV/SDA5 enable the specified swap partition

-A: Enable all swap partitions defined in the/etc/fstab file

-S: View swap partitions

SWAPOFF/DEV/SDA5 closing the specified swap partition

2.free-m viewing physical memory and swap partitions

3.DD command: Convert and copy files

if= Source Path data

of= Target Path data

BS: Specify block size, default unit is byte

Count: Specify the number of blocks

Seek: The size of skipped space, that is, the amount of false capacity created

Example 1: Backing up the MBR master boot record for this hard drive and restoring the/dev/sad

DD IF=/DEV/SDA of=/mnt/usb/sys.mbr Bs=1 count=512

DD if=/mnt/usb/sys.mbr OF=/DEV/SDA bs=512 count=1

Example 2: Creating and adding a swap partition with a file

DD If=/dev/zero of=/root/swapfile bs=1m count=256

Mkswap/root/swapfile

Swapon/root/swapfile

Example 3: Making a disc image

DD If=/dev/cdrom Of=/root/redhat6.iso

4./etc/fstab file is the file system configuration file

Mount mounts the appropriate device and must be written into the/etc/fstab file if it is to be long-lasting, or the machine restart will disappear

That is, each file system defined in the/etc/fstab file is automatically mounted at system startup

The /etc/fstab file format is as follows:

Device mount point to Mount file system type Mount option dump frequency file system detection sequence

/dev/sda5 /soft ext3 defaults 0 0

Dump frequency: Set a full backup number of days, 0 means no backup

File system detection sequence : only the root / can be 1, 0 means no detection

Mount-a: Mount the file system or partition device defined in the/etc/fstab file immediately

5.fuser: Verify the file or socket file that the process is using

-V: View running processes on a file

-K: Kill process, usually in combination with-M

-M: Related to mount file

fuser-km mount point: Terminates all processes that are accessing this mount point

Practice:

1, create a 1G partition, file system for ext3, volume labeled data, block size is 1024, reserve management space for the disk partition of 1%, require boot can automatically mount to the/data directory, it is best to enable label and ACL mount

FDISK/DEV/SDA New Partition/dev/sda5

Mke2fs-j-L data-b 1024-m 1/dev/sda5

Vim/etc/fstab Add the following line

Label= "DATA" /data ext3 defaults,acl 0 0

This article is from the "Xavier Willow" blog, please be sure to keep this source http://willow.blog.51cto.com/6574604/1765618

Linux file system swap swap partition and DD command details (3)