Storage Systems Flashcards
3 types of Storage Systems
Cache, Persistent, Object
Example of cache in GC
Memory Store - managed Redis service
1 benefit of cache
low latency - sub-millisecond access
3 problems of cache
- volatile - lost when machine shuts down
- more expensive than SSD or HDD
- can get out of sync with the system of truth (persistent storage)
Cache - quick definition
in memory data store
Persistent Storage - quick definition
durable block storage
Where can you use persistent storage?
Can be attached to VMs in Compute Engine and Kubernetes Engine.
Where is persistent storage located?
On the network. They are not attached to the physical servers hosting your VM. They exist independently of VMs.
Can a VM have locally attached persistent storage?
Yes. VM can have local SSD, but it is volatile.
Types of persistent storage
SSD and HDD
Differences between SSD and HDD
HDD have higher latency, but lower cost.
Network attached SSD are 40/20 times faster (R/W) than HDD. Locally attached SSD are 200/150 times faster.
Max size of SSD/HDD
64TB
4 facts of persistent storage
- can create file systems on them
- data is automatically encrypted
- size can be increased while mounted to VM
- can be mounted in read-only mode on multiple VMs at once
Is persistent storage zonal or regional?
Both. Regional replicates data across different zones, but is more expensive than purely zonal storage.
What is Object Storage good for?
large volumes of data that is shared widely