Does advice on aligning SSD block sizes apply to "cloud persistent disks?"

not_user9123 asked:

I recently read that differences between disk page size in the partition vs flash storage can hurt write performance.

So, I checked the partition sizes on some database disks with parted and got

Output: Sector size (logical/physical): 512B/4096B which obviously shows a difference.

However, I’m not sure if changing the partition size would help here.

We are using GCP’s zonal persistent ssd (not sure what the generic industry term is) and not a raw SSD.

Does the general advice on aligning SSD block sizes apply to “cloud persistent disks?”

My answer:


It doesn’t really matter.

The SSD page size is invisible and inaccessible to you, and it might even change during the lifetime of your persistent disk when the underlying storage is upgraded or replaced.

In any event all your disk reads and writes are going over a network anyway before they reach the storage server and finally get written to physical media.

Overall, on a cloud provider this is rarely worth worrying about. You’d see very little difference in performance, and the SSD lifetime is something for the cloud provider to worry about, not you.

And finally, your disk partitions are already aligned to a multiple of the SSD page size anyway.


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