The Under Repair value on the Dashboard page is the total amount of storage, in bytes, that is in need of repair. Storage needs to be repaired if it is allocated storage on drives are damaged or otherwise unreachable (for example, due to a drive failure), regardless of whether that allocated storage contains data. While any storage is in need of repair, that storage is referred to as the repair backlog.
When a drive with allocated storage becomes unavailable:
- The repair backlog increases by the size of that allocated storage.
- The amount of used storage decreases by the amount of used storage on that allocated storage.
To repair storage, the S Series Node re-creates that storage on available drives. As storage is repaired, the repair backlog decreases, and the amount of used storage increases.
Because allocated storage can contain storage that is not used, as storage is repaired, the repair backlog decreases more quickly than used storage increases. For example, suppose a failed drive has 5 TB of allocated storage. Also suppose that 3 TB of that allocated storage is used. Assuming no additional storage fails, as storage is repaired, the repair backlog decreases from 5 TB to 0 TB, and used storage increases by 3 TB in the same amount of time.
The Under Repair box has a link to the more detailed statistics listed below.
- Under repair
- The Under repair value is the total amount of storage, in bytes, that is in need of repair.
- Repair rate
- The Repair rate value is the estimated rate at which the S Series Node is currently working through the repair backlog, in bytes per second. This value is calculated as an average of the rates of repair starting from the most recent increase in the repair backlog and ending at the current time. In other words, when the repair backlog increases, the repair rate is reset to zero, and averaging starts fresh from that time.
- If the repair backlog is empty, the repair rate is zero.
- Data-access activity on the S Series Node can decrease the repair rate.
- Repair time to completion
- The Repair time to completion value is the estimated amount of time, in minutes, until the repair backlog is empty. This value is calculated as the size of the current repair backlog divided by the current repair rate. If the repair backlog is empty, the repair time to completion is set to zero.
- If the repair rate is zero, the value of Repair time to completion is Unknown.
- Projected used storage
- The Projected used storage value is the amount of used storage, in bytes, that is estimated to be on the S Series Node when the current repair backlog is empty. Projected used storage is the sum of the current amount of used storage and the amount of used storage on the allocated storage in the repair backlog. The accuracy of projected used storage increases as the amount of storage under repair decreases.
- The projected amount of used storage is also shown as a percent of total storage.