32 GB Canister Storage

[gladguy]

Hey there,

Wondering about the 32 GB Storage in canister?

How to deploy a canister with 32 GB enabled ?

Thanks in Advance

[domwoe]

Hey @gladguy,

you don’t need to enable anything. However, the 32 GB is not the normal WASM heap (still 4GB), but stable memory which needs to be accessed by the system API.

If you’re programming in Rust, there are some libraries that help work with stable memory. AFAIK there’s none for Motokot at the moment:

• GitHub - dfinity/stable-structures: A collection of data structures for fearless canister upgrades.
• https://crates.io/crates/ic-stable-memory

Update: There’s a WiP project for a StableBTree in Motoko: ICDevs.org - Bounty 24 - StableBtree Mokoko - up to $10k (cc @sardariuss)

[Manu]

@claudio wrote a post on how you can make use of 32GiB of stable mem in motoko here Motoko stable memory in 2022 - #10 by claudio. But as @domwoe points out, you’ll probably want to use some motoko equivalent of the rust “stable structures” repo, so this is something that still needs work.

[kentosugama]

Currently being worked on by @sardariuss. See here:

Completed: ICDevs.org - Bounty 24 - StableBtree Mokoko - up to $10k

I’d like to be able to transform Motoko basic types (essentially the Nat16/Nat32/Nat64 and resp. Int) types into an array of bytes. In rust this is done with to_le_bytes. Also if there is something that exists to convert a struct into such an array of bytes I’m taking it too. I think rust uses the trait #[repr(packed)] that allows to peform a safe cast into a pointer of u8, then converted into a vec. But I doubt something that straightforward is possible in Motoko. Otherwise I might continue wi…

[tomijaga]

Hey, just to clarify, do Motoko variables with the stable keyword get stored in stable memory or do you have to add them using the ExperimentalStableMemory API?

[domwoe]

Hey @tomijaga,

the stable annotation in Motoko only means that the variable is automatically serialized to stable memory during canister upgrades. But it still lives in the normal WASM heap in normal operation. Hence, you can’t make use of the stable memory increase currently, when only using the stable annotation.
See Stable variables and upgrade methods in the Documentation.

The ExperimenatalStableMemory API allows using the stable memory directly during normal operation of the canister.
See Stable Memory in the Documentation.