Thursday, 30 June 2016

Ubuntu Linux and the growing file-system

A friend asked me how to resize a disk partition ( virtual disk ) in an Ubuntu VM on VMware.

This is what I did: -

Look at the existing disk layout

df -kmh

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        19G  3.6G   15G  20% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
udev            478M  4.0K  478M   1% /dev
tmpfs            98M  1.5M   97M   2% /run
none            5.0M     0  5.0M   0% /run/lock
none            489M  216K  489M   1% /run/shm
none            100M   32K  100M   1% /run/user
/dev/sdb1       4.8G   10M  4.6G   1% /installs


Look at the underlying disk "drive"

fdisk /dev/sdb

Command (m for help): p

Disk /dev/sdb: 5368 MB, 5368709120 bytes
181 heads, 40 sectors/track, 1448 cylinders, total 10485760 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x9844eb8f

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    10485759     5241856   83  Linux

In VMware Fusion, I have TWO virtual disks


The second drive - Virtual Disk 2.vmdk - is the one in which I'm interested

Increase it from 5 GB to 10 GB, with the Linux VM shutdown


With this result


Now check the file-system in Linux

df -kmh

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        19G  3.6G   15G  21% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
udev            478M  4.0K  478M   1% /dev
tmpfs            98M  1.5M   97M   2% /run
none            5.0M     0  5.0M   0% /run/lock
none            489M  144K  489M   1% /run/shm
none            100M   28K  100M   1% /run/user
/dev/sdb1       4.8G   10M  4.6G   1% /installs

fdisk /dev/sdb

Command (m for help): p

Disk /dev/sdb: 10.7 GB, 10737418240 bytes
181 heads, 40 sectors/track, 2896 cylinders, total 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x9844eb8f

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    10485759     5241856   83  Linux

Nothing has changed, you cry

Now we delete the old partition :-)

Command (m for help): d
Selected partition 1


and then create a new one

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1): 
Using default value 1
First sector (2048-20971519, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): 
Using default value 20971519


Note that we start with the same block - 2048 - but that the end block is ~2x ( increased from 10,485,759 to 20,971,519 )

Write the new partition table

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: 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)
Syncing disks.


Error-check the virtual disk

e2fsck -f /dev/sdb1 

e2fsck 1.42.9 (4-Feb-2014)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/sdb1: 11/327680 files (0.0% non-contiguous), 55902/1310464 blocks

Resize the virtual disk

resize2fs /dev/sdb1 

resize2fs 1.42.9 (4-Feb-2014)
Resizing the filesystem on /dev/sdb1 to 2621184 (4k) blocks.
The filesystem on /dev/sdb1 is now 2621184 blocks long.

Mount the file-system

mount -a

Look at the new disk layout

df -kmh

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        19G  3.7G   15G  21% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
udev            478M  4.0K  478M   1% /dev
tmpfs            98M  1.5M   97M   2% /run
none            5.0M     0  5.0M   0% /run/lock
none            489M  144K  489M   1% /run/shm
none            100M   28K  100M   1% /run/user
/dev/sdb1       9.8G   12M  9.2G   1% /installs


Job, as they say, is a good 'un

With thanks to this: -

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