Persistent Disk Resize on the FLY

dharmendra mishra
2 min readAug 31, 2020

How many times you have to stop your VM and attach a new disk when you ran out of space and training and testing a model.

To resolve this ,here is the small article with commands.

It only applies on common case. The entire disk is reserved for a single partition.

Step 1: Go to URL select the project and click on the cloud shell.

To get the full view, write command

$export PS1=”$”

Step 2: Then Write Command

$ gcloud compute ssh 1 — zone=2

· 1 — Put the compute engine name in place of 1.

· 2 — Put the zone details in place of 2.

Step 3 : Remaining disk size available

$ df -h

Filesystem Size Used Avail Use% Mounted on

udev 1.8G 0 1.8G 0% /dev

tmpfs 371M 39M 332M 11% /run

/dev/sda1 50G 11G 38G 22% /

tmpfs 1.9G 0 1.9G 0% /dev/shm

tmpfs 5.0M 0 5.0M 0% /run/lock

tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup

/dev/sda1 is the line we are looking for. From the example above, you have noticed that you have used more than 1/4 of the disk size.

If the rate of use is over 80%, that’s not a good sign.

Step 4: Partition Check

$ sudo lsblk


sda 8:0 0 50G 0 disk

└─sda1 8:1 0 50G 0 part /

Noticing that sda only has one partition sda1, which is actually good as it makes things simpler.

Step 5: Go to the console and click on disks under the compute engine.

Select your VM and click on edit. Enter the size you want to increase.

Step 6: Now that you have increased the size however you still need to grow the partition.

$ sudo growpart /dev/sda 1

CHANGED: partition=1 start=2048 old: size=*** end=*** new: size=***


Asterisk are just a size for indication from start to end.

Step 7: The file system needs to resize.

sudo resize2fs /dev/sda1
resize2fs 1.42.13 (17-May-2015)
Filesystem at /dev/sda1 is mounted on /; on-line resizing required
old_desc_blocks = 13, new_desc_blocks = 63
The filesystem on /dev/sda1 is now **** (4k) blocks long.

Step 8: Verify by command

$ df –h

This is it, Enjoy!!



dharmendra mishra

Data-driven Analytics/Engineering leader with 12+ years of experience in digital advertising company. Skills SQL, Python, Excel and GCP Google Cloud Platform.