=========================================================
ϡ
Linux-3.7/Documentation/filesystems/btrfs.txt Ǥ
Ρ JF ץ < http://linuxjf.sourceforge.jp/ >
  2013/01/09
  Seiji Kaneko < skaneko at a2 dot mbn dot or dot jp >
=========================================================

	BTRFS
	=====

#Btrfs is a new copy on write filesystem for Linux aimed at
#implementing advanced features while focusing on fault tolerance,
#repair and easy administration. Initially developed by Oracle, Btrfs
#is licensed under the GPL and open for contribution from anyone.
Btrfs  Linux Υԡ饤ȥפοե륷ƥǡѾ
ȴưײ˽֤ĤŪʵǽ뤳Ȥ
äΤǤǽ Oracle ҤǳȯԤƤޤߤ GPL ǥ饤
󥹤졢ïι׸ǤƤޤ

#Linux has a wealth of filesystems to choose from, but we are facing a
#number of challenges with scaling to the large storage subsystems that
#are becoming common in today's data centers. Filesystems need to scale
#in their ability to address and manage large storage, and also in
#their ability to detect, repair and tolerate errors in the data stored
#on disk.  Btrfs is under heavy development, and is not suitable for
#any uses other than benchmarking and review. The Btrfs disk format is
#not yet finalized.
Linux Ǥǽʥե륷ƥब˭٤ˤޤãϸߤΥǡ
󥿡ĶǰŪˤʤĤĤ褦ʵʥȥ졼֥ƥޤǤ
ĥ¸뤿ˡ͡ʵŪĩ˼ȤǤޤե륷
ϵʥȥ졼򥢥Ӵ뵡ǽƳĥǤɬפ
ꡢޤǥΥǡΥ顼ȯѾ㳲¸ʤ
ޤBtrfs ϸ߱԰ճȯǤꡢ٥ޡ뤳Ȥȥӥ塼
ԤȰʳŪˤŬƤޤBtrfs ΥǥեޥåȤǽ
ǤȤϤʤäƤޤ

#The main Btrfs features include:
Btrfs μʵǽˤϰʲΤΤޤޤޤ

#    * Extent based file storage (2^64 max file size)
#    * Space efficient packing of small files
#    * Space efficient indexed directories
#    * Dynamic inode allocation
#    * Writable snapshots
#    * Subvolumes (separate internal filesystem roots)
#    * Object level mirroring and striping
#    * Checksums on data and metadata (multiple algorithms available)
#    * Compression
#    * Integrated multiple device support, with several raid algorithms
#    * Online filesystem check (not yet implemented)
#    * Very fast offline filesystem check
#    * Efficient incremental backup and FS mirroring (not yet implemented)
#    * Online filesystem defragmentation
    * ƥȥ١Υե륹ȥ졼 (ե륵 2^64 Х)
    * ʥեʣͤळȤˤ̤θΨŪ
    * ǥåǥ쥯ȥˤ̤θΨŪ
    * ưŪ inode γ
    * 񤭴ǽʥʥåץåȵǽ
    * ֥ܥ塼 (ե륷ƥ롼ȤʣĤȤǽ)
    * ֥ȥ٥Υߥ顼󥰤ȥȥ饤ԥ
    * ǡȥ᥿ǡΥå (ʣΥ르ꥺबǽ)
    * ̵ǽ
    * Ĥ RAID 르ꥺ󶡤롢ʣǥХݡȵǽ
    * 饤ե륷ƥå (̤)
    * ȤƤ®ʥե饤ե륷ƥå
    * ΨŪʺʬХååפȥե륷ƥߥ顼 (̤)
    * 饤ե륷ƥǥե饰ǽ



#	MAILING LIST
#	============
	᡼󥰥ꥹ
	================

#There is a Btrfs mailing list hosted on vger.kernel.org. You can
#find details on how to subscribe here:
vgar.kernel.org ǥۥƥ󥰤Ƥ Btrfs ᡼󥰥ꥹȤͭޤ
ɤΤξܺ٤ϰʲ

http://vger.kernel.org/vger-lists.html#linux-btrfs

#Mailing list archives are available from gmane:
᡼󥰥ꥹȥ֤ϡgmane 󶡤Ƥޤ

http://dir.gmane.org/gmane.comp.file-systems.btrfs



	IRC
	===

#Discussion of Btrfs also occurs on the #btrfs channel of the Freenode
#IRC network.
Btrfs ˴ؤϡFreenode IRC ͥåȥ #btrfs ͥǤԤ
Ƥޤ



#	UTILITIES
#	=========
	桼ƥƥ
	==============

#Userspace tools for creating and manipulating Btrfs file systems are
#available from the git repository at the following location:
Btrfs ե륷ƥ뤿Υ桼֥ġϰʲ git 
ݥȥ꤫Ǥޤ

 http://git.kernel.org/?p=linux/kernel/git/mason/btrfs-progs.git
 git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git

#These include the following tools:
ǤϡʲΥġ뤬Ǥޤ

#mkfs.btrfs: create a filesystem
mkfs.btrfs: ե륷ƥġ

#btrfsctl: control program to create snapshots and subvolumes:
btrfsctl:   ʥåץåȤȥ֥ܥ塼ץ

	mount /dev/sda2 /mnt
	btrfsctl -s new_subvol_name /mnt
	btrfsctl -s snapshot_of_default /mnt/default
	btrfsctl -s snapshot_of_new_subvol /mnt/new_subvol_name
	btrfsctl -s snapshot_of_a_snapshot /mnt/snapshot_of_new_subvol
	ls /mnt
	default snapshot_of_a_snapshot snapshot_of_new_subvol
	new_subvol_name snapshot_of_default

#	Snapshots and subvolumes cannot be deleted right now, but you can
#	rm -rf all the files and directories inside them.
	ʥåץåȤȥ֥ܥ塼ϸߤΤȤǤޤ󤬡
	ƤΥեȥǥ쥯ȥ rm -rf ǺǤޤ

#btrfsck: do a limited check of the FS extent trees.
btrfsck:   ե륷ƥ२ƥڤˡꤵ줿åԤ

#btrfs-debug-tree: print all of the FS metadata in text form.  Example:
btrfs-debug-tree: ƤΥե륷ƥ᥿ǡƥȷǽϤ
Ȥʲ˼ޤ

	btrfs-debug-tree /dev/sda2 >& big_output_file
	
