如何在谷歌计算引擎中访问启动盘作为数据盘

Question

I have to been trying to follow steps mentioned in this https://cloud.google.com/marketplace/docs/partners/vm/build-vm-image#create_a_licensed_vm_image guide to offer VM solution on google cloud marketplace.

With reference to step number 5 in the above link:-

The data disk shows up on my system with its boot and a data partition, but it is not mounted anywhere. I am able to access my installed application files on my current boot disk, which is weird since I did not install my application on this boot disk.

Here is my gcloud command for first instance.

gcloud compute instances create vm \
--image-family centos-7 \
--image-project centos-cloud \
--no-restart-on-failure \
--maintenance-policy=TERMINATE --preemptible

Here is my gcloud command for second instance.

gcloud compute instances create vm2 \
--image-family centos-7 \
--image-project centos-cloud \
--no-restart-on-failure \
--maintenance-policy=TERMINATE --preemptible \
--disk=name=vm,mode=rw,boot=no

Could someone please explain me step number 5 regarding boot disk cleanup in the link I mentioned above.

Answer 1

I figured it out. It seems that even though I am attaching the previous boot disk as data disk, the 2nd instance boots up with the previous boot disk (this behavior is random). lsblk outputs two identical boot disks. Now if i find my application running, then it means that I booted from the first boot disk otherwise the second. The only workaround I found for this issue is to spawn the 2nd instance first, wait for it to completely boot and then attach the previous boot disk as data disk.