mfsmetadump(8)

NAME
mfsmetadump - dump MooseFS metadata info in human readable format

SYNOPSIS
mfsmetadump [-d] [-s section_name] metadata_file

DESCRIPTION
mfsmetadump dumps MooseFS metadata info in human readable format. Output consists of several sections with different types of information. Every section consist of header data - rows starting with hash (#) sign - and content data (may be empty).

OPTIONS

-d - replace all non-printable characters (codes < 32 and > 126) with '.' (it was default behaviour in version < 3.0.110).

-s - dump only specified section of the file. Possible sections:
	HEAD - header info
	SESS - client sessions
	LABS - labels (not used)
	SCLA - storage classes
	PATT - pattern overrides
	NODE - tree nodes (i-nodes)
	EDGE - tree edges (file names)
	FREE - free nodes (deleted i-nodes)
	QUOT - quota definitions
	XATR - xattr data
	PACL - posix acl data
	OPEN - open files
	FLCK - flock data
	PLCK - posix locks (lockf,ioctl) data
	CSDB - active chunkservers
	CHNK - chunks

metadata_file
    path to metadata.mfs file

NOTES
Each metadata section - with the exception of the HEAD section - consist of a constant set of HEADER fields and a variable set of this section specific fields. HEAD section contains only section specific fields. The HEADER fields and all the section fields are listed below:

  SECTION HEADER

section header
    section header (section type + version)

length
    length of section

section type
    name of section

version
    hexadecimal representation of section version

  FILE HEADER SECTION (HEAD)

header
    MooseFS version

version
    metadata file version

fileid
    metadata file id

  SESSIONS SECTION (SESS)

nextsessionid
    first free session id

statscount
    number of stats remembered in each session

SESSION
    line describing a single session
    s	session id
    e	exports checksum
    p	IP address
    r	root inode number
    f	session flags
    u	umask
    g	min and max goal (redundancy level)
    t	min and max trash retention
    m	maproot uid,gid and mapall uid,gid
    x	disabled operations
    d	disconnection time (optional)
    c	current hour stats data
    l	last hour stats data
    i	session name (usually local mount point)

  STORAGE CLASS SECTION (SCLA), formerly LABELS SECTION (LABS)

LABELDESC
    line with label description (existed only in LABS)
    l	label letter
    n	label description

SCLASS
    (formerly LABELSET) line with storage class used in system
    #	storage class id
    x	admin only
    m	mode
    d	arch delay
    c	create labels
    k	keep labels
    a	archive labels
    n	name

SCLASSMAIN
    (used in version 4.0+ instead of SCLASS) line with common parameters of storage class
    #	storage class id
    x	admin only
    m	create mode
    a	arch mode
    d	arch delay
    t	min trash retention
    n	name

SCLASSEXPR
    (used in version 4.0+ instead of SCLASS) line with label expression
    #	storage class id
    t	type ([C]reate,[K]eep,[A]rchive or [T]rash)
    e	expression

  PATTERNS SECTION (PATT)

PATTERN
    line with pattern definition
    v	priority
    #	storage class id
    t	trash retention
    e	flags (extra mfs attributes)
    u	uid
    g	gid
    p	pattern

  NODES SECTION (NODE)

maxinode
    maximum inode number used by system

hashelements
    number of inodes in hash tabble

NODE
    line with node (inode) description
    k	node type (-,D,S,F,B,C,L,T,R)
    	-	file
    	D	directory
    	S	socket
    	F	fifo
    	B	block device
    	C	character device
    	L	symbolic link
    	T	trash file
    	R	sustained file (removed open file)
    i	inode number
    #	storage class id
    e	flags (extra mfs attributes)
    w	windows attributes
    m	mode
    u	uid
    g	gid
    a,m,c	atime, mtime, ctime
    t	trash retention
    d	rdevhi,rdevlo (only block and character devices)
    p	path (only symbolic links)
    l	file length (only files)
    c	chunk list (only files)
    r	sessions that have this file open (only files)

  EDGES SECTION (EDGE)

nextedgeid
    next available edge id (descending)

EDGE
    line with edge description
    p	parent inode number
    c	child inode number
    i	edge id
    n	edge name

  FREE NODES SECTION (FREE)

free nodes
    number of free (reusable) nodes

FREEID
    line with free inode description
    i	inode number
    f	deletion timestamp

  QUOTA SECTION (QUOT)

quota nodes
    number of nodes with quota

QUOTA
    line with quota description
    i	inode number
    g	grace period
    e	exceeded
    f	flags
    s	soft quota exceeded timestamp
    si	soft inode quota
    hi	hard inode quota
    sl	soft length quota
    hl	hard length quota
    ss	soft size quota
    hs	hard size quota
    sr	soft real size quota
    hr	hard real size quota

  XATTR SECTION (XATR)

XATTR
    line with xattr description
    i	inode number
    n	xattr name
    v	xattr value

  POSIX ACL SECTION (PACL)

POSIXACL
    line with acl description
    i	inode number
    t	acl type
    u	user (file owner) permissions
    g	group permissions
    o	other permissions
    m	permission mask
    n	named permissions - list of objects:
    u(U):P	permissions P for user with uid U
    g(G):P	permissions P for group with gid G

  OPEN FILES SECTION (OPEN)

OPENFILE
    line with open file description
    s	session id
    i	inode number

  FLOCK LOCK SECTION (FLCK)

FLOCK
    line with flock-lock description
    i	inode number
    s	session id
    o	lock owner (FUSE lock owner)
    t	lock type ('R' - shared lock, 'W' - exclusive lock)

  POSIX LOCK SECTION (PLCK)

POSIXLOCK
    line with posix-lock description
    i	inode number
    s	session id
    o	lock owner (FUSE lock owner)
    p	local process id (owner pid)
    r	lock range in format <START,END)
    t	lock type ('R' - shared lock, 'W' - exclusive lock)

  CHUNKSERVERS SECTION (CSDB)

chunk servers
    number of chunkservers

CHUNCKSERVER
    line with chunk server description
    i	server ip
    p	server port
    #	server id
    m	maintenance mode
    t	maintenance timeout timestamp

  CHUNKS SECTION (CHNK)

nextchunkid
    first available chunk number

CHUNK
    line with chunk description
    i	chunk number
    v	chunk version
    t	timestamp, if in the future, means lock timestamp, if in the past, last modification timestamp
    a	archive flag
    (s,#)	list of entries, s is storage class id, # is number of files in this storage class containing this chunk
    c	calculated storage class id (effectively used class id, if a chunk has more than one)

NOTICE! If a chunk's timestamp equals 0, it means the chunk was created by MooseFS version older than 4.45.0 and has not been locked or modified since.

REPORTING BUGS
Report bugs to <bugs@moosefs.com>.

COPYRIGHT
Copyright (C) 2026 Jakub Kruszona-Zawadzki, Saglabs SA

This file is part of MooseFS.

MooseFS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2 (only).

MooseFS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, see <https://www.gnu.org/licenses/>.

SEE ALSO
mfsmaster(8)