resize2fs

TLDR

Resize to maximum possible size

$ sudo resize2fs /dev/sdXN

Resize to specific size with progress

$ sudo resize2fs -p /dev/sdXN 40G

Shrink to minimum possible size

$ sudo resize2fs -M /dev/sdXN

Force resize even if errors detected

$ sudo resize2fs -f /dev/sdXN

SYNOPSIS

resize2fs [-fFpPMbs] [-d debug-flags] [-S RAID-stride] device [size]

DESCRIPTION

resize2fs resizes ext2, ext3, or ext4 filesystems. It can grow or shrink the filesystem. Note that it does not resize the underlying partition; use a partitioning tool for that.

PARAMETERS

-b

Enable 64-bit block numbers

-d DEBUG-FLAGS

Enable debugging output

-f

Force resize even with errors

-F

Flush buffer cache before resize

-M

Shrink to minimum size

-p

Show progress bar

-P

Print minimum size and exit

-s

Disable 64-bit block numbers

-S STRIDE

Specify RAID stride for optimal placement

SIZE UNITS

Size can be specified as number of blocks, or with suffixes:
s: 512-byte sectors
K: Kilobytes
M: Megabytes
G: Gigabytes

Shrinking a filesystem requires it to be unmounted. Growing a filesystem can often be done while mounted (online resize) for ext3/ext4. Always resize the partition before growing or after shrinking the filesystem.

HISTORY

resize2fs is part of e2fsprogs. Online resize capability was added in ext3 and improved in ext4.