I am just very confused at this point. If all data on Solana are stored in Memory what if the whole network shutdown or restarts whether all data is removed? I thought it must stored data in Hardware also
Validators store data on their machine's hard disk. Since Solana is a fast network, it produces a lot of transactions, logs in a short period of time. Once validator reach its maximum space, they move all the data to GoogleTables. Since validators do a lot of read and write operations they usually use NVMe (nonvolatile memory express) storage
Currently entire historical ledges sits in Google Table and this is a risk. Data in Google Table is not immutable, it is like a regular database, any data can be deleted any time.
Storing data in Google Table is the single point of failure. Even DDOS attack on the DNS network would take down the system
Solana was working with Arweave before but Arweave's infrastructure was not capable of handling Solana's fast transaction. Arweave's RPC servers were going down. Google Table is just a temporary solution. They are working for better options