Safe Pledge: pFIL Service Level

Safe pledge is the portion of pledged FIL in a MinerActor that should not be affected by any mining penalties. It ensures that each pFIL is always backed by a pledged FIL. Every pFIL minted must be backed by 1 FIL worth of “safe” asset pledged to the protocol. The safety of these assets will be compromised if the underlying assets are slashed due to miner faults. In the rare event that the miner is continuously faulting, a forced termination is a necessary risk control measure to ensure that the liquidated assets are sufficient to continue backing pFIL.

Safe Pledge is the maximum amount of pFIL that a user can mint. It is calculated at the time of pFIL minting, given how much FIL is currently locked in the miner (EligibleAsset), the current fees incurred to liquidate the miner (BaseTerminationFee), and a sensible buffer (Buffer).

Safe Pledge = EligibleAsset - BaseTerminationFee - Buffer

The EligibleAsset of a miner refers to the current balance of the miner, after paying down its outstanding pFIL and pre-commit deposits.

The BaseTerminationFee is the fee incurred to terminate all sectors in a miner. It is dynamic and is calculated at the point of termination by the Filecoin protocol itself. Therefore, the protocol continuously calculates and monitors the termination fees of all miners. Refer to the official docs for more information.

The Buffers are constants incorporated to withstand several days of continuous slashing due to sector faults.

After the Safe Pledge value for a miner is calculated and pFIL is minted, the protocol will still continue monitoring the miner’s risk factor, as the EligibleAsset of a miner can change due to slashing.

Should the EligibleAsset drop below a warning threshold, the system will issue a warning through public channels like Twitter or Slack. This gives storage providers adequate time to react and repair their sector by topping up funds. Subsequently, if no remedy action is taken and EligibleAsset drops below the termination threshold, the protocol will carry out forced terminations to ensure that the liquidated assets can continue to be used to back pFIL. This also ensures enough funds are recovered to repurchase the minted pFIL.

In addition, Storage Providers can only withdraw funds from their pledge MinerActor when they reclaim ownership, once they have repaid their outstanding pFIL.

The following diagram depicts the various thresholds of the MinerActor’s asset that will be constantly monitored by the protocol.

All Storage Providers (SPs) who have repledged their Miner Actors with Parasail are strongly advised to closely monitor the health of their miner assets. If there's a significant decrease in asset value, please top up funds to the Miner Actor to prevent forced termination.