The Storage Efficiency value on the Dashboard page is a percent representing the ratio between the amount of data ingested for the objects currently stored on the S Series Node and the current amount of used storage and under-repair storage on the S Series Node.
Normally, due to metadata and to data protection, the amount of storage required to store an object is greater than the size of the data ingested for the object. However, S Series Nodes can single-instance object data, including the data protection. Single-instancing means storing and protecting only one copy of the data for multiple objects that have the same ingested data.
The S Series Node does not single-instance object metadata. As a result, when the data ingested for multiple objects is single-instanced, the amount of used storage increases only by the size of one copy of the protected object data plus the size of the metadata for each of those objects. As a result, a large amount of single-instancing can increase storage efficiency.
If no objects stored on the S Series Node have duplicate data, storage efficiency is typically around 77%. Storing mostly small objects without duplicate data can decrease storage efficiency due to the amount of metadata stored for each object. Storing mostly large objects with single-instancing can result in a storage efficiency that's greater than 100% because the amount of ingested data is larger than the amount of storage used to store and protect that data.
Ingest rate, object size, object deletion rate, and the amount of storage under repair can all affect the estimates of storage efficiency. The process of repairing storage can temporarily increase storage efficiency.
Before any objects are stored on the S Series Node, the Dashboard shows N/A for storage efficiency.
The Storage Efficiency box has a link to the more detailed statistics listed below.
- Ingested data
- The Ingested data value is the total number of bytes of data written to the S Series Node for all objects currently stored on the S Series Node.
- Used storage
- The Used storage value is the total amount of storage, in bytes, that is currently occupied by object data, object or system metadata, scavenging metadata, or data and metadata protection overhead.
- Under repair
- The Under repair value is the amount of storage, in bytes, that is in need of repair. Storage needs to be repaired if it is allocated storage on drives that are no longer available (for example, due to a drive failure), regardless of whether that allocated storage contains data.
- Storage efficiency
- The Storage efficiency value is a percent representing the ratio between the amount of data ingested for the objects currently stored on the S Series Node and the current amount of used storage and under-repair storage on the S Series Node.
- Object data
- The Object data value is the total amount of data, in bytes, stored for all objects currently stored on the S Series Node. Due to single-instancing, the amount of object data stored on the S Series Node can be less than the amount of ingested data.
- Storage overhead
- The Storage overhead value is a fixed multiplier used in calculating the amount of storage saved by single-instancing.
- Single-instance savings
- The Single-instance savings value is the total amount of storage, in bytes, saved by the single-instancing of existing objects. Single-instancing means storing only one copy of the data for two or more objects that have the same data.
- The S Series Node stores the metadata for each object independently of any other object. No part of object metadata is ever single-instanced.
- The amount of storage saved by single instancing is calculated as the amount of ingested data minus the amount of used storage, multiplied by the storage overhead value. The storage overhead multiplier accounts for the savings generated by protecting only the single copy of the data.
- Available storage
- The Available storage value is the total amount of storage, in bytes, that is currently available for storing and protecting object data and object and system metadata. Available storage does not include storage that is reserved for use in repairing damaged storage.
- Unique-data storage efficiency
- The Unique-data storage efficiency value is a fixed percent (approximately 76.92%) representing the ratio between the amount of data ingested for any given object and the amount of storage required to store and protect that data, assuming that single-instancing is not in effect.
- Ingestible at current efficiency
- The Ingestible at current efficiency value is the estimated amount of data, in bytes, that can be ingested into the S Series Node before no more data can be stored or protected, assuming that ingest patterns and the rate of single-instancing remain constant.
- Ingestible with unique data
- The Ingestible with unique data value is the estimated amount of data, in bytes, that can be ingested into the S Series Node before no more data can be stored or protected, assuming that ingest patterns remain constant and that no duplicate data is ingested.
- Time until full
- The Time until full value is the estimated amount of time, in days, until the amount of available storage is zero. This value is based on historical ingest trends.
- When no storage is available, the S Series Node becomes read-only, and no more data can be ingested.