Btrfs features and common operations

Btrfs is a powerful new file system, let's look at its features and common operations

Core Features:
Multi-Physical volume support: Btrfs can be composed of multiple underlying physical volumes, RAID support for online "add", "Remove", "modify";
Copy-on-write update mechanism (CoW): Copy, update, and replace pointers instead of "in-place" updates;
Data and meta-data check code: Checksum detection Integrity
Sub-Volume: Sub_volume
Snapshots: snapshots that support snapshots;
Transparent compression: Performs compression operations when stored, and supports no-pressure viewing, saving space

Case process:

1. Create Btrfs:
   

   Using Mkfs.btrfs
   -l ' label ': Specify LABEL to create file system
   -D <type>: Indicates the cross-disk storage of data for increased IO efficiency or data security, support for RAID0, RAID1, RAID5, Raid6, RAID10, single
   -M <profile>: Indicates the cross-disk storage of metadata for increased IO efficiency or data security, support for RAID0, RAID1, RAID5, Raid6, RAID10, single, DUP
   -O <feature>: Indicates that certain file system features are turned on
   -O List-all: Lists all supported feature;
   

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Use of 2.BTRFS file systems

Supports many subcommands to achieve its powerful functions

To create a Btrfs file system:

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View:

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View label :

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using blkid to see the SDB1 and SDC1 's UUID ,sub_uuid is different:

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Mount:

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To create a file in the Mount directory:

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You can also use the transparent compression mechanism to mount:

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Adjust file system size online :

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Add, remove, scan devices and more :

Add a device to the currently specified Btrfs file system

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Balance the previous data on the newly added disk

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when the amount of data is particularly large, you can also IO Peak Pause balance operation, cancel pause, interrupt, etc., here is no longer redundant

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before removing the physical volume,btrfs will automatically move the data above and then remove it, without the need to manually remove the data as LVM does.

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only sdb2 and sdc1 were found ,sdb1 was removed :

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view data is still in ;

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Reproduce organization data across disk storage formats

-M represents meta data

-D represents data

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Sub-volume Features:

Create a sub-volume and view:

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Mount a sub-volume:

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To view Sub-volume information:

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Files in a child volume can be accessed through the parent volume:

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To delete a sub-volume:

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Snapshot: Note that a snapshot of a child volume must be in the same parent volume as the child volume

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To delete a snapshot:

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Take a snapshot of a single file and verify that:

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Ext Series File system and btrfs file System lossless conversion:

first create a ext4 file system:

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then mount and create the file in the Mount directory, convert to btrfs with Btrfs-convert

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View:

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The file is also:

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Rollback to EXT4 file system: using the- r option

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This article is from the "After Tomorrow" blog, please be sure to keep this source http://leeyan.blog.51cto.com/8379003/1689638

Btrfs features and common operations