The Total Storage value on the Dashboard page is the total amount of storage, in bytes, that can be used for storing, protecting, and repairing object data and object and system metadata. Total storage includes storage only on drives that are known to the S Series Node and are available. If a drive is removed from the S Series Node or becomes unavailable (for example, due to drive failure), the storage on that drive is not included in the calculation of total storage.
When drives are added to the S Series Node, total storage increases. Similarly, when an unavailable drive becomes available, total storage increases.
The Total Storage box has a link to the more detailed statistics listed below.
- Raw drive storage
- The Raw drive storage value is the total of the vendor-specified capacity, in bytes, of all the data and database drives known to the S Series Node, including both available and unavailable drives. Raw drive storage does not include space partitioned for purposes other than storage. This partitioned space is unavailable to systems that incorporate the drive.
- System overhead
- The System overhead value is the total amount of storage, in bytes, that the S Series Node reserves for internal purposes on all the data and database drives, including both available and unavailable drives. System overhead includes the internal database, information used in storage management, and information used in data and metadata recovery, should that become necessary.
- The amount of space reserved for system overhead on any given drive is fixed and is relative to the amount of raw storage on the drive. On data drives, which have a raw storage amount of 10 TB or higher, system overhead is insignificant, using approximately 0.4 percent of raw capacity. Database drives have a smaller amount of raw storage, under 1 TB. System overhead on a database drive can use as much as 37 percent of raw capacity.
- System storage
- The System storage value is the total amount of storage, in bytes, that remains when system overhead is subtracted from raw drive storage. System storage includes storage on all drives, both available and unavailable, that are known to the S Series Node.
- Unavailable storage
- The Unavailable storage value is the total amount of storage, in bytes, on data and database drives that are known to the S Series Node but are currently unavailable. The S Series Node cannot use unavailable storage for any purpose.
- Total storage
- Total storage equals raw drive storage minus system overhead minus unavailable storage, in bytes. The S Series Node uses system storage for storing, protecting, and repairing object data and object and system metadata.
- If no drives are unavailable, total storage equals system storage.