Tune2fs Quick Tips

What is tune2fs ?

tune2fs adjusts tunable filesystem parameters on a Linux second extended filesystem.

Tune2fs brings the ability to modify various parameters on a file system volume that may not be the best or require some changes to reflect the needs of the environment. One example is Ubuntu: by default Ubuntu verifies file system integrity every 33 mounts/bootups or every 120 days(whichever comes first), while well intended the defaults may not be the best on a test or development system which may be subject to frequent reboots.

Tune2fs is easy to understand, I will walk you through what I consider to be some of the most common uses for tune2fs.

More Information

You can always consult the man pages for more information. Just use:

$ man tune2fs

Change integrity amount and time

I tend to boot Ubuntu more than 33 times a month, which is why I always increase the number of mounts.

$ sudo tune2fs -c 120 -i 3m /dev/sdb1
tune2fs 1.40.8 (13-Mar-2008)
Setting maximal mount count to 120
Setting interval between checks to 7776000 seconds

– c max_mount_count This option is responsible for the number of mounts before the integrity check is done.
– i interval-between-checks This option is responsible for the mounts of days the system should wait before performing an integrity check. d = days | w = weeks | m = months, in this example the check is to be performed every 3 months -i 3M.

Disable file system integrity check

While dangerous some people may opt to disable checks all at once.

$ sudo tune2fs -i 0 /dev/sda1
tune2fs 1.40.8 (13-Mar-2008)
Setting interval between checks to 0 seconds

-i 0 – This option disables checks based on time of the file system. Be careful the system will no longer perform integrity check after this options is selected.

Change the name of a volume

Changing the volume label name may be useful for personal labeling porpuses such as changing the name of a portable drive. Use the -l parameter to list the name of the filesystem superblock.

$ sudo tune2fs -l /dev/sda1 | grep volume
Filesystem volume name:   /home/user

Capital -L parameter will change the volume-label name. In this example I am changing the name from /home/user to myhome.

$ sudo tune2fs -L myhome /dev/sda1
tune2fs 1.40.8 (13-Mar-2008)

Verify the new name change.

$ sudo tune2fs -l /dev/sda1 | grep volume
Filesystem volume name:   myhome

Display file system superblock information

Lots of valuable information.

$ sudo tune2fs -l /dev/sdb1

tune2fs 1.40.8 (13-Mar-2008)
Filesystem volume name:   
Last mounted on:          
Filesystem UUID:          f060d692-53fd-4180-811c-f20bcf7f24d0
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype n                                                                                                 eeds_recovery sparse_super large_file
Filesystem flags:         signed_directory_hash
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              3932160
Block count:              15727627
Reserved block count:     786381
Free blocks:              15557651
Free inodes:              3932146
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      1020
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   256
Filesystem created:       Sun May  9 00:43:38 2010
Last mount time:          Sun May  9 01:05:38 2010
Last write time:          Sun May  9 01:05:38 2010
Mount count:              2
Maximum mount count:      33
Last checked:             Sun May  9 00:43:38 2010
Check interval:           15552000 (6 months)
Next check after:         Fri Nov  5 00:43:38 2010
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:               128
Journal inode:            8
Default directory hash:   tea
Directory Hash Seed:      949c1e9b-19b3-437f-be23-05b14a671d3a
Journal backup:           inode blocks