Resize FS on Linux (extend partition size)

resize-fs.txt

root@stg530:~# fdisk -l

Disk /dev/sdb: 32 GiB, 34359738368 bytes, 67108864 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x9ccb23b5

Device     Boot Start      End  Sectors Size Id Type
/dev/sdb1         128 67106815 67106688  32G 83 Linux

Disk /dev/sda: 256 GiB, 274877906944 bytes, 536870912 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0xf728ee4d

Device     Boot Start       End   Sectors  Size Id Type
/dev/sda1        2048 268435455 268433408  128G 83 Linux

root@stg530:~# fdisk -u /dev/sda

Welcome to fdisk (util-linux 2.25.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help): p
Disk /dev/sda: 256 GiB, 274877906944 bytes, 536870912 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0xf728ee4d

Device     Boot Start       End   Sectors  Size Id Type
/dev/sda1        2048 268435455 268433408  128G 83 Linux


Command (m for help): d
Selected partition 1
Partition 1 has been deleted.

Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-536870911, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-536870911, default 536870911):

Created a new partition 1 of type 'Linux' and of size 256 GiB.

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Re-reading the partition table failed.: Device or resource busy

The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8).

root@stg530:~# df -h .
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       126G  101G   20G  84% /
root@stg530:~# reboot
root@stg530:~# resize2fs /dev/sda1
resize2fs 1.42.12 (29-Aug-2014)
Filesystem at /dev/sda1 is mounted on /; on-line resizing required
old_desc_blocks = 16, new_desc_blocks = 32
The filesystem on /dev/sda1 is now 67108608 (4k) blocks long.

root@stg530:~# df -h .
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       252G  101G  141G  42% /
root@stg530:~# exit