# resize2fs

## NAME



           resize2fs - ext2/ext3/ext4 file system resizer
    


## SYNOPSIS



           **resize2fs**[ **-fFpPMbs**] [ **-d** _debug-flags_ ] [ **-S** _RAID-stride_ ] [ **-z**
           _undo_file_ ] _device_ [ _size_ ]
    


## DESCRIPTION



           The **resize2fs** program will resize ext2, ext3, or ext4 file
           systems.  It can be used to enlarge or shrink an unmounted file
           system located on _device_.  If the file system is mounted, it can
           be used to expand the size of the mounted file system, assuming
           the kernel and the file system supports on-line resizing.  (Modern
           Linux 2.6 kernels will support on-line resize for file systems
           mounted using ext3 and ext4; ext3 file systems will require the
           use of file systems with the resize_inode feature enabled.)
    
           The _size_ parameter specifies the requested new size of the file
           system.  If no units are specified, the units of the _size_
           parameter shall be the file system blocksize of the file system.
           Optionally, the _size_ parameter may be suffixed by one of the
           following units designators: 'K', 'M', 'G', 'T' (either upper-case
           or lower-case) or 's' for power-of-two kilobytes, megabytes,
           gigabytes, terabytes or 512 byte sectors respectively. The _size_ of
           the file system may never be larger than the size of the
           partition.  If _size_ parameter is not specified, it will default to
           the size of the partition.
    
           The **resize2fs** program does not manipulate the size of partitions.
           If you wish to enlarge a file system, you must make sure you can
           expand the size of the underlying partition first.  This can be
           done using fdisk(8) by deleting the partition and recreating it
           with a larger size or using lvextend(8), if you're using the
           logical volume manager lvm(8).  When recreating the partition,
           make sure you create it with the same starting disk cylinder as
           before!  Otherwise, the resize operation will certainly not work,
           and you may lose your entire file system.  After running fdisk(8),
           run resize2fs to resize the ext2 file system to use all of the
           space in the newly enlarged partition.
    
           If you wish to shrink an ext2 partition, first use **resize2fs** to
           shrink the size of file system.  Then you may use fdisk(8) to
           shrink the size of the partition.  When shrinking the size of the
           partition, make sure you do not make it smaller than the new size
           of the ext2 file system!
    
           The **-b** and **-s** options enable and disable the 64bit feature,
           respectively.  The resize2fs program will, of course, take care of
           resizing the block group descriptors and moving other data blocks
           out of the way, as needed.  It is not possible to resize the file
           system concurrent with changing the 64bit status.
    


## OPTIONS



           **-b** Turns on the 64bit feature, resizes the group descriptors
                  as necessary, and moves other metadata out of the way.
    
           **-d** _debug-flags_
                  Turns on various resize2fs debugging features, if they have
                  been compiled into the binary.  _debug-flags_ should be
                  computed by adding the numbers of the desired features from
                  the following list:
                       2    - Debug block relocations
                       4    - Debug inode relocations
                       8    - Debug moving the inode table
                       16   - Print timing information
                       32   - Debug minimum file system size (-M) calculation
    
           **-f** Forces resize2fs to proceed with the file system resize
                  operation, overriding some safety checks which resize2fs
                  normally enforces.
    
           **-F** Flush the file system device's buffer caches before
                  beginning.  Only really useful for doing **resize2fs** time
                  trials.
    
           **-M** Shrink the file system to minimize its size as much as
                  possible, given the files stored in the file system.
    
           **-p** Print out percentage completion bars for each **resize2fs**
                  phase during an offline (non-trivial) resize operation, so
                  that the user can keep track of what the program is doing.
                  (For very fast resize operations, no progress bars may be
                  displayed.)
    
           **-P** Print an estimate of the number of file system blocks in
                  the file system if it is shrunk using **resize2fs** 's **-M** option
                  and then exit.
    
           **-s** Turns off the 64bit feature and frees blocks that are no
                  longer in use.
    
           **-S** _RAID-stride_
                  The **resize2fs** program will heuristically determine the RAID
                  stride that was specified when the file system was created.
                  This option allows the user to explicitly specify a RAID
                  stride setting to be used by resize2fs instead.
    
           **-z** _undo_file_
                  Before overwriting a file system block, write the old
                  contents of the block to an undo file.  This undo file can
                  be used with e2undo(8) to restore the old contents of the
                  file system should something go wrong.  If the empty string
                  is passed as the undo_file argument, the undo file will be
                  written to a file named resize2fs-_device_.e2undo in the
                  directory specified via the _E2FSPROGS_UNDO_DIR_ environment
                  variable.
    
                  WARNING: The undo file cannot be used to recover from a
                  power or system crash.
    


## KNOWN BUGS



           The minimum size of the file system as estimated by resize2fs may
           be incorrect, especially for file systems with 1k and 2k
           blocksizes.
    


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