GCE : VM IMAGE
- Images contains boot Loader, Root file system
- Everything you need to start compute engine
- Images are stored in GCS images service.
Types of images :
- Private images – maintain by you
- Public images – maintain by google community supported images
A custom image is a boot disk image that you own and control access to use
Custom image for the following tasks:
- Import a boot disk
- Create an image
- Copy one image to another image
Compute Engine >Images
Instance templates & instance group :–
Global Instance Templates define the machine type,image,zone, and other instance properties for the instance in a managed instance group
Instance Group :-
Manged Instance Group
- Zonal manage
- regional Managed
- Use Identical instance Resource
- Used for Auto-Scaling
- Rolling Update can be done
- Change to instance will make change in all the instance
- Load balancing for only similar resource
Unmanaged instance group:-
- Use non-identical instance resource.
- Can not be used for auto scaling
- Rolling update cannot be used
- Can make arbitrary change in any instance
- Can be used for load balancing pre-existing resources or Group of dissimilar resources.
Compute engine > instance templates
Compute engine > instance group.
Compute engine GCE : Preemptibility :-
- Preemptible VM consideration
- Can not live migrate and auto restart
- 24 hours max use and not covered under SLA
- Changed if only started for 10 min, Less use will not be used
- When you attach GPU to preemption – you quota will be used.
- Compute Engine sends signal per preemptible to VM 30 sec
- Average preemption rate varies between 5% and 15% per seven days per project
Pricing other Aspects :-
- Disk Pricing – Prorated to second
- Snapshots – only charged for amount used.
- Unused static IP are charged per hour’s (1 Cent Currently)
- Custom Machine types charged for per vCPU ,per RAM GB
- Perdefine machine are mostly cost less than equivalent custom Machine type
- Network egress based on type of egress used
- No ingress to vm or almost all GCP service
Inferred instance discount – perdefine ,custom
Committed use Discount
Simple and flexible : discounts apply to the aggregate number of vCPU or memory within a region so they are not affected by change to your instance’s machine type.
No upfront costs : there are no upfront costs for committed use discount. Committed use discounts are applied to your bill every month