Confusion on disk types in gcloud when creating a new disk

Question

So I'm looking at the disk types available on the google cloud platform and they have Persistent disks and Local SSD disks (from reading their documentation). After dreading the docs I go to create a disk the disk types are labeled as 'SSD Persistent disk' and 'Standard Persistent disk'. They seems to be named different here to in the docs. I just want a confirmation that:

SSD Persistent disk = Local SSD disk

Standard Persistent disk = Persistent disks

I'm new to running VMs on a cloud platform for hosting your own site and im trying to wrap my head around the different options available for all the different settings and why you would choose one over the other..

I'm trying to learn the different disks available and what they do but when I go to actually create a disk the types they have avaliable aren't even the same as the ones they list in the docs. I figured they could be the same but named different for whatever reason so I wanted to come here and confirm if thats the case.

Answer 1

Your choices are:

1. local SSD = locally-attached to the VM, SSD
2. standard persistent = network-attached, persistent, HDD**
3. SSD persistent = network-attached, persistent, SSD

Type 1 is lower latency than types 2 and 3, because type 1 is physically attached to the VM.

Type 2 and 3 persist beyond instance stop/delete. Type 1 does not.

Type 2 and 3 are durable/redundant (Google replicates them, like Raid 1). Type 1 is not.

Type 2 and 3 can be attached to multiple VMs simultaneously (in read mode). Type 1 cannot.

** nowhere does Google actually indicate afaik that standard persistent is actually HDD, just that it is not SSD, so it may not be guaranteed to be HDD.

You can see more specific data at Storage Options, but in summary:

• local SSD is the fastest (by far)
• SSD persistent has much higher read/write IOPS than standard persistent
• SSD persistent is more expensive (4x) than standard persistent