StorageTier (Alluxio Core - Common Utilities 295 API)

```
public interface StorageTier
```
Represents a tier of storage, for example memory or SSD. It serves as a container of StorageDir which actually contains metadata information about blocks stored and space used/available.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`long`	`getAvailableBytes()`
`long`	`getCapacityBytes()`
`StorageDir`	`getDir(int dirIndex)`	Returns a directory for the given index.
`java.util.List<java.lang.String>`	`getLostStorage()`
`java.util.List<StorageDir>`	`getStorageDirs()`
`java.lang.String`	`getTierAlias()`
`int`	`getTierOrdinal()`
`void`	`removeStorageDir(StorageDir dir)`	Removes a directory.

- Method Detail
  - getTierOrdinal
```
int getTierOrdinal()
```
    Returns:
    
    the tier ordinal
  - getTierAlias
```
java.lang.String getTierAlias()
```
    Returns:
    
    the tier alias
  - getCapacityBytes
```
long getCapacityBytes()
```
    Returns:
    
    the capacity (in bytes)
  - getAvailableBytes
```
long getAvailableBytes()
```
    Returns:
    
    the remaining capacity (in bytes)
  - getDir
```
@Nullable
StorageDir getDir(int dirIndex)
```
    Returns a directory for the given index.
    
    Parameters:
    
    dirIndex - the directory index
    
    Returns:
    
    a directory, or null if the directory does not exist
  - getStorageDirs
```
java.util.List<StorageDir> getStorageDirs()
```
    Returns:
    
    a list of directories in this tier
  - getLostStorage
```
java.util.List<java.lang.String> getLostStorage()
```
    Returns:
    
    a list of lost storage paths
  - removeStorageDir
```
void removeStorageDir(StorageDir dir)
```
    Removes a directory.
    
    Parameters:
    
    dir - directory to be removed