# TOP Mainnet FAQ

# What's the address format of TOP

The ordinary user account address of the TOP mainnet starts with T80000, followed by the Base58 encoding of the public key hash.

For details on the address format, see Account Address.

# How to check your remaining free disk spaces

Run the following command in the SSH terminal to check the remaining disk space in the root directory.

df -h

An example of the returned message is as follows:

return

The directory with the content of "/" in the Mounted on column is the root directory, and the Avail column shows the remaining free space.

In the figure above, the root directory is /dev/vda1, and the remaining free space is 81G.

# How to add administrator privilege for non-root users

If non-root users need to perform administrative operations, administrator privilege needs to be added (no need for root users).

Determine if you are the root user:

Connect to your cloud host, the logged-in user is displayed as [root@xxxx ~], if it starts with root, you are a root user; otherwise, you are a non-root user.
For a non-root user, run the following command.
```
sudo -v
```
- If nothing is returned after running the command, it means that you already have the corresponding privilege, you can skip the step of adding administrator privilege and continue with the subsequent upgrade process.
- If it returns Sorry, user xxxx may not run sudo on localhost. after running the command, you need to add the corresponding privilege.
If you need to add the corresponding privilege, you need to run the following command to switch to the root user and log in.
```
su - root
```
After logging in, run the following command according to your system type to add administrator privilege. If nothing is returned after execution, the execution is successful.

Replace your username with your login user name.
- If your system is CentOS, run:
```
sudo usermod your username -a -G wheel
```
- If your system is Ubuntu, run:
```
sudo usermod your username -a -G sudo
```

# How to transfer tokens to the TOP address of HiWallet in TOPIO

You can transfer tokens to other account addresses in the TOPIO with the following commands.

Since the TOP address created in the HiWallet wallet also exists in the TOP mainnet, this method can also be used to transfer tokens.

topio transfer T800002276a7d58218ac4978733e5cca927a7d86cb7c87 20

In which:

T800002276a7d58218ac4978733e5cca927a7d86cb7c87 is the recipient's account address.
20 is the transfer amount.

For more details about transfers, see Transfer.

# How much is the transaction fee for on-chain transfers

By default, if the account balance is greater than or equal to 100 TOP tokens, the account will be given 25,000 Tgas for free every 24 hours, which allows the account to make multiple free transactions per day.

This means that every account can enjoy completely free transactions multiple times every day.

# How will I continue to get more Gas if the free gas runs out

If you run out of free gas, you can also exchange for additional gas by locking (depositing) TOP tokens. You can get the Gas in the TOPIO with the following command:

topio resource stakeForGas 1000

In which, 1000 is the number of TOP tokens locked (deposited).

For more details about exchanging Gas, please refer to Account Resources.

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