The StorageDeviceDescriptor entity captures the properties of a physical disk or other storage devices. In case of network-based storage, the speeds and latencies should account for the properties of the (dedicated) transport fabric.

Attribute
<Primitive Type> Unlimited Natural	writeSpeed	Average write speed, in bytes per second. Even though most contemporary disks support write caching, but this is a dangerous feature (unless the cache is battery backed) and is typically turned off.
<Primitive Type> Unlimited Natural	readSpeed	Average read speed, in bytes per second. For single disk and random requests, this is in tens of megabytes per second. For cached requests, this may correspond to the link speed of the interface, but I assume that averages are sufficient.
<Primitive Type> Double	requestLatency	The average latency before the disk starts to serve a particular request, in seconds. The service time, however, is determined by the latency and the time it takes to transfer the data of the request.
<Primitive Type> Unlimited Natural	cacheSize	Size of the disk cache, in bytes. Disk caches exhibit low hit-after-read or hit-after-write ratio, but high hit ratio of yet unread data that have been fetched into the cache by the disk read-ahead mechanism (during sequential read).

!!TableHeading.InheritedAttributes!! samm::deployment::hardware::HardwareDescriptor

!!TableHeading.InheritedAttributes!! samm::core::NamedEntity

name

!!TableHeading.InheritedAttributes!! samm::core::Entity

documentation

!!TableHeading.InheritedAttributes!! identifier::Identifier

id

!!TableHeading.InheritedOperations!! samm::deployment::hardware::HardwareDescriptor

!!TableHeading.InheritedOperations!! samm::core::NamedEntity

!!TableHeading.InheritedOperations!! samm::core::Entity

!!TableHeading.InheritedOperations!! identifier::Identifier

 cacheSize

Public <Primitive Type> Unlimited Natural cacheSize

Size of the disk cache, in bytes. Disk caches exhibit low hit-after-read or hit-after-write ratio, but high hit ratio of yet unread data that have been fetched into the cache by the disk read-ahead mechanism (during sequential read).

Eigenschaften:

Aggregation	None
Alias
Association
Association End
Class	<Class> StorageDeviceDescriptor
Datatype
Default
Default Value
Is Composite	false
Is Derived	false
Is Derived Union	false
Is Leaf	false
Is Ordered	false
Is Read Only	false
Is Static	false
Is Unique	true
Keywords
Lower	1
Lower Value
Multiplicity	1
Name	cacheSize
Name Expression
Namespace	<Class> StorageDeviceDescriptor
Opposite
Owned Template Signature
Owner	<Class> StorageDeviceDescriptor
Owning Association
Owning Template Parameter
Qualified Name	samm::deployment::hardware::StorageDeviceDescriptor::cacheSize
Stereotype
Template Parameter
Type	<Primitive Type> Unlimited Natural
Upper	1
Upper Value
Visibility	Public

 readSpeed

Public <Primitive Type> Unlimited Natural readSpeed

Average read speed, in bytes per second. For single disk and random requests, this is in tens of megabytes per second. For cached requests, this may correspond to the link speed of the interface, but I assume that averages are sufficient.

Eigenschaften:

Aggregation	None
Alias
Association
Association End
Class	<Class> StorageDeviceDescriptor
Datatype
Default
Default Value
Is Composite	false
Is Derived	false
Is Derived Union	false
Is Leaf	false
Is Ordered	false
Is Read Only	false
Is Static	false
Is Unique	true
Keywords
Lower	1
Lower Value
Multiplicity	1
Name	readSpeed
Name Expression
Namespace	<Class> StorageDeviceDescriptor
Opposite
Owned Template Signature
Owner	<Class> StorageDeviceDescriptor
Owning Association
Owning Template Parameter
Qualified Name	samm::deployment::hardware::StorageDeviceDescriptor::readSpeed
Stereotype
Template Parameter
Type	<Primitive Type> Unlimited Natural
Upper	1
Upper Value
Visibility	Public

 requestLatency

Public <Primitive Type> Double requestLatency

The average latency before the disk starts to serve a particular request, in seconds. The service time, however, is determined by the latency and the time it takes to transfer the data of the request.

Eigenschaften:

Aggregation	None
Alias
Association
Association End
Class	<Class> StorageDeviceDescriptor
Datatype
Default
Default Value
Is Composite	false
Is Derived	false
Is Derived Union	false
Is Leaf	false
Is Ordered	false
Is Read Only	false
Is Static	false
Is Unique	true
Keywords
Lower	1
Lower Value
Multiplicity	1
Name	requestLatency
Name Expression
Namespace	<Class> StorageDeviceDescriptor
Opposite
Owned Template Signature
Owner	<Class> StorageDeviceDescriptor
Owning Association
Owning Template Parameter
Qualified Name	samm::deployment::hardware::StorageDeviceDescriptor::requestLatency
Stereotype
Template Parameter
Type	<Primitive Type> Double
Upper	1
Upper Value
Visibility	Public

 writeSpeed

Public <Primitive Type> Unlimited Natural writeSpeed

Average write speed, in bytes per second. Even though most contemporary disks support write caching, but this is a dangerous feature (unless the cache is battery backed) and is typically turned off.

Eigenschaften:

Aggregation	None
Alias
Association
Association End
Class	<Class> StorageDeviceDescriptor
Datatype
Default
Default Value
Is Composite	false
Is Derived	false
Is Derived Union	false
Is Leaf	false
Is Ordered	false
Is Read Only	false
Is Static	false
Is Unique	true
Keywords
Lower	1
Lower Value
Multiplicity	1
Name	writeSpeed
Name Expression
Namespace	<Class> StorageDeviceDescriptor
Opposite
Owned Template Signature
Owner	<Class> StorageDeviceDescriptor
Owning Association
Owning Template Parameter
Qualified Name	samm::deployment::hardware::StorageDeviceDescriptor::writeSpeed
Stereotype
Template Parameter
Type	<Primitive Type> Unlimited Natural
Upper	1
Upper Value
Visibility	Public