Can we downgrade from a IO1 SSD to a GP2 SSD ebs volume in AWS?

Question

I am currently using a gp2 elastic volume and i wanted to upgrade to io1 volume in AWS for high iops for a few days now i wanted to know once i upgrade it then after a few days will i be able to downgrade it back to gp2 and if it is possible,is their any loss of data or any such scenario possible please help.

I know how to upgrade the volume but i am not sure about downgrading it so if anyone has ever tried it please help.

current volume: gp2

i used this command to upgrade:

aws ec2 modify-volume --volume-type io1 --iops 10000 --size 200 --volume-id vol-1

what should be the appropriate way to downgrade it.

Answer 1

Although changing from gp2 to io1 might seem like an upgrade and changing back from io1 to gp2 might seem like a downgrade, the truth is more nuanced, because each volume type¹ has certain use cases where it is the best choice.

As a rule, you can change from any volume type to any other volume type, with only one class of documented volume type-related exceptions, due to mounting and size constraints on st1 and sc1 volumes.

So changing from one type to another type is generally a non-issue, but the same thing is not true of size. It is not possible to make an EBS volume smaller. They can only be made larger.

EBS volume modifications are a safe operation, and can even be done "hot" with the disk still in use... but as a matter of best practice, you should always take an EBS snapshot before attempting a modification.

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¹each volume type except standard. I can't think of any case where a standard volume would be the best choice.