(This article is a practical guide for hosting using the UI. For a technical explanation of hosting, check Hosting The most recent update of this guide was on August, 2017.)

In Sia, hosts are rewarded with Siacoins by offering their free disk space and hosting the files of renters.

There are some requisites to start hosting:

• An installed and preferably fully synced with the blockchain Sia client.

• A wallet already unlocked.

• A minimum of 2000SC for setting up Collateral. However more collateral will be required for hosting large amounts of data. About 20,000-50,000SC per Terabyte is advised.

• At least 20Gb of free space to offer.

• A static public IP address. Otherwise renters will not be able to reach the host if the internet provider changes your IP over time. Alternatively, a DNS domain pointing to the hosting computer can be used. There are available several free DNS providers, for example NoIP.com.

• Ports 9981 and 9982 open in the firewall and port-fowarded in the router to the hosting computer.

• A reliable connection, with the hosting computer being available 24 hours per day, 7 days per week. An availability of 97% of the time (uptime) is required.

• Keeping the integrity of the data is the sole responsibility of the host, and accidental (or intended) data loss will incur in economic damage for the host (collateral being lost). While not a requirement, keeping the hosted data in a redundancy scheme, like a RAID array, is advisable.

• For the same reason, it is advisable to do frequent backups of the metadata stored on the Sia folders “Host”, “Wallet” and “Transactions” (on Windows, located in %Appdata%). In case of a computer crash, these files are required together with the hosting folders to restore the host.

Most of the hosting operations can be performed on the “Hosting” tab of the UI, but there are certain advanced operations that need to be done in the Terminal (or in a Command Line Interface).

The “Hosting” tab of the UI shows most of the parameters to configure:

• Max Duration (in weeks): The maximum duration of file contracts the host will accept. By default, the UI for renters makes 13 week-long contracts. However advanced users may try to make longer or shorter contracts, so it is in the hand of the host deciding if accepting those longer contracts.

• Collateral (in SC/TB/month): the collateral is a guarantee you offer to the renter that his data will be available and intact during the whole contract. If files are deleted, or the 97% uptime is not met, the collateral will be lost.

• Storage price (in SC/TB/month): The pricing for storing the files.

• Bandwidth price (in SC/TB): The pricing charged every time a file is uploaded or downloaded. The UI does not allow establishing individual upload and download prices. This can be done in the terminal with the commands host config minuploadbandwidthprice [price]SC and host config mindownloadbandwidthprice [price]SC . Example: host config minuploadbandwidthprice 10SC . Take in mind that “upload” and “download” are referred from the renter’s perspective. Thus, the download pricing represents your upload (outbound traffic) and vice versa.

• Accepting Contracts slider: will enable or disable the acceptance of future contracts. Those already formed will keep running and their owners can keep uploading or downloading files until they expire.

• Conversion Rate is an indicator of the probability, due the scoring of the host (see also bellow), to be selected for new contracts.

• Storage Folders: Folders for storing the renter’s files can be added, removed and resized in this section. If a folder containing data is made smaller than its contents, or removed, the contents will be automatically moved to other folders with available space.

Depending on the parameters of the host, including the pricing, a score will be assigned by potential renters of the network. Sia network is a competitive marketplace, meaning that hosts with competitive pricing have higher chances to get more file contracts. For comparison, SiaHub.info can be checked to see what other hosts in the network are pricing.

There are other advanced parameters that can be stablished in the Terminal (or in a CLI) with the syntax host config [parameter] . For a list of all possible parameters, type host config –h:

• Collateralbudget (in SC): The maximum amount of collateral you want to offer for all your contracts. Once exhausted, you will not accept new contracts.

• Maxcollateral (in SC per contract): Maximum amount of collateral that will be allocated in a single contract. Larger contracts will be rejected by the host.

• Mincontractprice (in SC): Minimal contract that will be accepted by the host.

Once parameters are set up, click on the Announce button on the top of the tab. A transaction will be broadcasted to the network and included in the blockchain, announcing the new host. By default, the public IP, using the 9982 port, will be used for the announce. If a DNS or a different port is desired, the command host announce [IP_or_DNS]:[port] can be used in the Terminal.

The settings can be changed at any time after announcing the host, but they will not affect any of the current contracts, only the new ones formed.

There is no need to announce again the host after changing these settings. Only announce again if the IP or DNS provider has to be changed.

Over time, contracts will be formed with renters. With every contract formed, the collateral to back it will become locked, and so an outbound transaction will be shown in the transactions history. Space disk is not reserved until files are actually uploaded.

The host will need to be online around a 97% of the time and keep the integrity of the files in order to fulfill Proofs of Storage to the blockchain (see also Contracts).

Payments are not received until the end of each contract. As default contracts are 13 weeks-long, it is usual not receiving payments until 3 months after the initial announcement.

The top bar of the “Hosting” tab shows: a) the connection status of the host, b) the number of contracts, c) The earned Siacoins, and d) the expected Siacoins to be earnt once all the current contracts expire. (see Figure below).

It is important to note that both earned and expected incomes shown in the UI represent a sum of several concepts:

• Proper storage revenue

• Bandwidth (upload and download) revenue

• Fees compensation. A 3.9% of the collateral will be paid in fees to the SiaFunds holders. If the host is successful in the contract, these fees will be paid by the renter from his allowance. While this is a payment (and represents a big part of what is shown in the UI), it actually does not represent a revenue, as it is a part of the collateral that the host already paid in advance and is just being returned.

A detailed itemization of earned coins and expected revenues, together with more parameters and statistics, can be checked with the command siac host -v in the Terminal. This is an example of the report:

This is the explanation of some of the shown data:

• Connectability Status: shows if the host is online and can be reached by the network

• Transaction Fee Compensation: the collateral fees that have been returned by the renter. Potential compensation is also shown.

• Transaction Fee Expenses: the collateral fees paid in the end to Siafunds holders by the host due to failed contracts.

• Storage revenue represents the revenue due to the proper storing of data. Potential revenue is also shown.

• Download and Upload Revenues show the amounts charged to the renter due to bandwidth costs.

• Locked collateral represents the total collateral used to back current contracts.

• Risked collateral shows the part of the collateral that is backing actual files and might be lost if the contract fails. As the renter uploads more files, more collateral will be added to Risked.

• Lost collateral represents the risked collateral that ended up lost (burnt, by sending it to an unspendable address) due to failed contracts.

• RPC Stats represent communications (calls) of other network nodes and renters with the host. For instance, “Settings Calls” show the number of times other clients of the network (potential renters) ask the host for his pricing and other settings.

The status of the host can be monitored remotely by checking its IP in Sia metrics webpages like SiaHub.info.

• If the host successfully pass the Proofs of Storage, showing he kept the files intact with an uptime of about 97%, by the end of the contract: all the storage and bandwidth costs are paid to the host, the collateral is returned and the 3.9% of collateral fees are paid back by the renter.

• If the contract is not successful: storage and bandwidth costs are not paid, collateral is not returned and the collateral fees are not returned, being finally paid by the host. It makes no difference if the host was available a 0% or a 90% of the time: if the contract fails, all payments and collateral is lost for that contract