Before creating a contract, the command
renter prices can be introduced in the UI terminal to provide an estimate of the current network pricing and expected fees.
In the File tab, pressing the “Create allowance” button opens the allowance pop-up (see Figure). In Sia, renters do not choose an amount of space and length of the contract. Instead the contract length is established in 13 weeks (3 months) with auto-renewal activated (see below) and the renters establishes an amount of Siacoin that will pay for the storage space estimated in the allowance window. As the allowance is used for both storage and bandwidth costs, if the renter frequently downloads his files, the allowance could exhaust sooner than the estimation.
The client also provides an estimate of the fees that will be deducted. While the unused part of the allowance is returned by the end of the contract, fees are not. Fees include:
After accepting the allowance, a process of forming contracts with 50 hosts will start, taking approximately one hour (See Figure).
Hosting is a competitive process where each host establishes his pricing. The client of the renter scores each host according to parameters as pricing, age of the host in the network and remaining free space. The client will automatically pick up 50 of the top-ranked hosts to form contracts with them. At the current moment, the renter can’t select specific hosts, and the process relies entirely in the scoring system. Siacoins will be deducted as contracts form to fulfill the minimal contract sizes requested by each host (see Figure).
After the 50 contracts are formed, the user can upload files using the UI interface buttons or drag-and-dropping the files. Sia accepts folder hierarchy for the uploads. Sia works splitting files in chunks of 40MB (as of September 2017), so files smaller than that size will be treated as 40MB files. For that reason, for uploading a large number of small files, it is recommended to upload a compressed file instead, in order to maximize the allowance use and improve the performance of the Client.
The “Files Transfers” button will show the progress of the uploads and downloads.
The pricing (different for each host) is established with each host during the contract formation. Posterior changes made by the host do not affect current contracts. Siacoins will be deducted as files are added for paying:
More details about the amount spent on each concept can be obtained typing
renter in the Terminal.
Files will be encrypted and uploaded to several hosts. At the right of each file an icon indicates the current redundancy achieved. The current target redundancy is 3x.
The hosts of the contract and the amount spent on each one can be checked with command
renter contracts on the Terminal.
Files can be downloaded by selecting them and clicking the “Download” button on the bottom of the screen. Download progress can be checked pressing the “Files Transfers” button at the top right (see Figure).
The allowance can be increased to allow more uploads and downloads by clicking again in “Create Allowance” and indicating the new total allowance amount. Note that even if it looks like a new allowance will be created, the result instead will be a change of the allowance size of the current contract.
During the length of the contract, hosts will have to accomplish their Proofs of Storage. If a particular host misses several of them, it will be determined that he is offline and so the redundancy for some files will drop. If redundancy drops below a certain value, a process of file repair will start even if the file is no longer in the renter's computer (a Remote File Repair). However, the renter's client must be online and with the wallet unlocked to create the new required contracts.
New hosts will be added to replace the bad hosts and they will receive the data the bad hosts were holding from other online hosts. This process can be detected by the fact that a number larger than 50 contracts is shown on the top of the UI (see Figure).
The repair process incurs in some expenses for the renter: a new contract will be added (between 2 and 5SC in minimal contract concept) and the data storage and bandwidth of the replacement host will be charged to the allowance.
After a repair, a redundancy bigger than 3x for a file represents that the missing host has returned back online.
After 6 weeks of creating the allowance, the Sia client by default will try to auto-renew it for 13 extra weeks. More Siacoins will be added to the allowance automatically to extend the storage of the current uploaded files. It is important to note that the auto-renewal can happen only if the renter is online, so opening the Sia client some time before the expiration of the contract is advised to avoid losing the data.
Those hosts that proved to be unreliable in uptime terms, or were inaccessible to upload data during the previous contract, will be replaced by new hosts. If hosts have changed their scoring compared to the previous contract formation (for instance because they increased their pricing), some of them will be replaced as well by more competitive hosts.
To stop the auto-renewal of the contract, type
renter allowance cancel. Cancelling the allowance will make the files inaccessible immediately.
Once a contract with a host expires, the unused part of the allowance will be returned to the renter. Also, if the host did not fulfill the 97% uptime requirement, the 3.9% of the collateral’s fees will be paid by the host instead of the renter. Data is erased from the hosts as soon as the contract expires.
In the case of a crash of the renter's computer, the recovery seed is currently not enough for recovering the uploaded files. The metadata included in the folders
wallet is essential for this process. For this reason, good practices include very frequent backups of these folders (as well as the Sia installation, for convenience) and having these folders on a disk with RAID or other redundancy. They can be found in the following locations:
|Operating system||Sia data directory|
|Mac OS X||