Uly.me

cloud engineer

GCP Display Device Names on OS

In GCP console you can see the VM’s Device Names. In this case, it’s boot and persistent-disk-1.

Name		          Device name
server-boot               boot	
server-data               persistent-disk-1

To display the volume names on the OS, run this command.

$ ls -l /dev/disk/by-id
total 0
lrwxrwxrwx. 1 root root  9 Aug  2 01:12 google-boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Aug  2 01:12 google-boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Aug 18 18:48 google-persistent-disk-1 -> ../../sdb
lrwxrwxrwx. 1 root root  9 Aug  2 01:12 scsi-0Google_PersistentDisk_boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Aug  2 01:12 scsi-0Google_PersistentDisk_boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Aug 18 18:48 scsi-0Google_PersistentDisk_persistent-disk-1 -> ../../sdb

As you can see, boot and persistent-disk-1 are displayed along with its device names /dev/sda and /dev/sdb.

GCP Identify Your Disks

Here’s how to identify your disks on the system to cross check with GCP Dashboard.

ls -l /dev/disk/by-id

Result:

[root@servername ~]# ls -l /dev/disk/by-id
total 0
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 google-boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Sep 15 05:30 google-boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 google-persistent-disk-1 -> ../../sdb
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 scsi-0Google_PersistentDisk_boot -> ../../sda
lrwxrwxrwx. 1 root root 10 Sep 15 05:30 scsi-0Google_PersistentDisk_boot-part1 -> ../../sda1
lrwxrwxrwx. 1 root root  9 Sep 15 05:30 scsi-0Google_PersistentDisk_persistent-disk-1 -> ../../sdb

GCP Disks Attach To An Instance

Here’s how to display a list the disks attached to an instance.

gcloud compute instances describe instance-name \
--project project-id \
--zone us-central1-c \
--format='yaml(disks[].source)'

Extend Regional Persistent Disks

Here’s the command to extend your regional persistent disks.

gcloud compute disks resize disk-name \
--size 100 \
--project project-id \
--region us-central1

Or you can specify by zone.

gcloud compute disks resize disk-name \
--size 100 \
--project project-id \
--zone us-central1-c

Display the updated disk details.

gcloud compute disks list \
--filter="name=disk-name" \
--project project-id

Although you’ve increased disk size, the file system doesn’t know the extra space. Run this (for XFS).

xfs_growfs /dev/sdb

GCP Move Instance to Another Project

Here’s how to copy a disk from one project to another.

gcloud compute disks create lamp-server \
--source-snapshot https://www.googleapis.com/compute/v1/projects/project-id/global/snapshots/lamp-server \
--project next-project-id \
--zone us-central1-a

Once all the disks are copied. You can create a snapshot of the boot.

gcloud compute disks snapshot lamp-server

Create an instance from snapshot.

gcloud compute disks create "hostname-boot" \
--project "project-id" \
--zone "us-central1-a" \
--source-snapshot "snapshot-name" \
--type "pd-standard" \
--size "100"