extfs

Info about the Linux ext filesystems

Filesystem options

as listed by 'tune2fs -l Device'

Filesystem volume name:   <none>

mke2fs -L [Label]

tune2fs -L [Label]

Last mounted on:          /root

(fstab)

Filesystem UUID:          3dc2fc2b-931e-492c-bd73-c1241e55c10e

mke2fs -U [UUID]

tune2fs -U [UUID|clear|random|time]

'random' option uses the 'uuidgen' command

Filesystem magic number:  0xEF53

static value

ext2, ext3 and ext4 have a common magic number of 0xef53

Filesystem revision #:    1 (dynamic)

mke2fs -r [0|1]

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

mke2fs -O [Options]

tune2fs -O [Options]

Filesystem flags:         signed_directory_hash
Default mount options:    (none)

tune2fs -o [Options]

debug, bsdgroups, user_xattr, acl, uid16, journal_data, journal_data_ordered, journal_data_writeback

Filesystem state:         clean

static

Errors behavior:          Continue

tune2fs -e [continue|remount-ro|panic]

Filesystem OS type:       Linux

mke2fs -o [Name]

Inode count:              1310720

mke2fs -N [Number]

Block count:              5242880
Reserved block count:     262144

mke2fs -m [Percentage]

tune2fs -r [Count]

tune2fs -m [Percentage]

actual percentage: "Reserved block count" *100 / "Block count"

default: 5

Free blocks:              4405971
Free inodes:              1231655
First block:              0
Block size:               4096

mke2fs -b [Blocksize] # 1024, 2048, 4096

Fragment size:            4096

mke2fs -f [Bytes]

Reserved GDT blocks:      1022
Blocks per group:         32768

mke2fs -g [Blocks]

Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Flex block group size:    16

mke2fs -G [Number of groups]

Filesystem created:       Thu Oct 14 14:34:50 2010

static value

Last mount time:          Fri Nov  5 09:58:33 2010

static value

Last write time:          Fri Nov  5 09:58:33 2010

static value

Mount count:              4

tune2fs -C [Count]

Maximum mount count:      -1

tune2fs -c [Count]

Last checked:             Thu Oct 14 14:34:50 2010

tune2fs -T [strftime|now]

Check interval:           0 (<none>)

tune2fs -i [Interval(d|w|m)]

Lifetime writes:          5477 MB
Reserved blocks uid:      0 (user root)

tune2fs -u [User(name|id)]

Reserved blocks gid:      0 (group root)

tune2fs -g [Group(name|id)]

First inode:              11
Inode size:               256

mke2fs -I [Bytes]

cannot be increased

Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
First orphan inode:       1179845
Default directory hash:   half_md4
Directory Hash Seed:      165766e9-88bb-4b00-94c3-eae4bdbed865

related to the dir_index feature

Journal backup:           inode blocks
Journal features:         journal_incompat_revoke
Journal size:             128M
Journal length:           32768
Journal sequence:         0x0000be2f
Journal start:            18366

---

Missing/Unknown

tune2fs:

-j journal options

-M last-mounted-directory

mkfs:

-E extended-options

-i bytes-per-inode

-M last-mounted-directory

-t fs-type

-T usage-type