I'm trying to create a smaller version of a Rasbian OS Lite image. I have tried to run resize2fs -M /dev/sda2 on the SD card root partition.
But as you can see below, after resize2fs there is still a huge number of free blocks. Mounting it you can also see there is 12% free space. What am I missing here? Can't I reduce the size of an ext4 fs more than this?
Also, why isn't the block count same as df reported fs size? 263798*4096 (1030M) vs 979M
pi@raspberry:~ $ sudo resize2fs -p -M /dev/sda2
resize2fs 1.46.2 (28-Feb-2021)
Resizing the filesystem on /dev/sda2 to 263798 (4k) blocks.
Begin pass 2 (max = 1)
Relocating blocks XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 3 (max = 9)
Scanning inode table XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The filesystem on /dev/sda2 is now 263798 (4k) blocks long.
pi@raspberry:~ $ sudo tune2fs -l /dev/sda2
tune2fs 1.46.2 (28-Feb-2021)
Filesystem volume name: rootfs
Last mounted on: /
Filesystem UUID: 6d2ff93e-eacd-415c-96d5-4611ad21e05f
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file dir_nlink extra_isize metadata_csum
Filesystem flags: unsigned_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 73440
Block count: 263798
Reserved block count: 1999
Free blocks: 35619
Free inodes: 37552
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 95
Blocks per group: 32768
Fragments per group: 32768
Inodes per group: 8160
Inode blocks per group: 510
Flex block group size: 16
Filesystem created: Thu Sep 22 00:23:04 2022
Last mount time: Sat Oct 15 20:14:34 2022
Last write time: Sat Oct 15 20:49:03 2022
Mount count: 0
Maximum mount count: -1
Last checked: Sat Oct 15 20:33:10 2022
Check interval: 0 (<none>)
Lifetime writes: 2152 MB
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 256
Required extra isize: 32
Desired extra isize: 32
Journal inode: 8
Default directory hash: half_md4
Directory Hash Seed: 2691ef59-d6a4-453d-8399-6bf963318a73
Journal backup: inode blocks
Checksum type: crc32c
Checksum: 0xa9df5888
pi@raspberry:~ $ sudo mount /dev/sda2 /mnt/sda2
pi@raspberry:~ $ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 29G 880M 27G 4% /
devtmpfs 333M 0 333M 0% /dev
tmpfs 462M 0 462M 0% /dev/shm
tmpfs 185M 980K 184M 1% /run
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
/dev/mmcblk0p1 255M 50M 206M 20% /boot
tmpfs 93M 0 93M 0% /run/user/1000
/dev/sda2 979M 840M 116M 88% /mnt/sda2 <-- THIS ONE
pi@raspberry:~ $ sudo resize2fs -p -d 32 -M /dev/sda2
resize2fs 1.46.2 (28-Feb-2021)
fs has 35888 inodes, 5 groups required.
fs requires 223086 data blocks.
With 5 group(s), we have 158747 blocks available.
Added 2 extra group(s), blks_needed 223086, data_blocks 224283, last_start 160989
Last group's overhead is 5093
Need 62097 data blocks in last group
Final size of last group is 67190
Estimated blocks needed: 263798
The filesystem is already 263798 (4k) blocks long. Nothing to do!
