NSR device

The NSR device resource describes each storage device used by a Backup server.To edit the NSR device resources for a Backup server use "nsradmin " or "nwadmin"

The NSR device resource has the following attributes:

• The name attribute specifies the path name for a device. For systems that optionally support "Berkeley style" tape positioning on close, the BSD style tape device name should be used. For optical disks the path name is generally the "c" partition.

  To facilitate interaction with external media management services a logical device type has been defined. When interacting with such services, the device into which a volume is loaded may be determined by the media management service. A logical device is used to define a Backup device resource.

  At the time of definition the name of a device is not related to any specific device. The default for both the media type and family are set to logical. The name, type, and family are not determined until the media management service has loaded a volume into a device in response to a request made by Backup. The name, type, and family of the actual device are then stored in the attributes logical name, logical type, and logical family, respectively. The association between the logical device and the actual device last only as long as a volume is loaded into the device and allocated for use by Backup.

• The media type attribute specifies the media type used by a device. Some of the possible values for this attribute are:

  • 4mm, 4mm digital audio tape (1 GB)

  • 8mm, 8mm video tape (2 GB)

  • dlt, digital linear tape cartridge (10 GB)

  • vhs, VHS data grade video tape (14 GB); 3480 - high-speed cartridge tape (200 MB)

  • logical, used when interacting with an external media management service.

• The enabled attribute indicates whether a device is available for use.

• The read only attribute indicates whether a device is reserved for read only operations, such as recover or retrieve.

• The target sessions attribute specifies the target number of saves for a device, and used for load-balancing. Once all the devices have reached their corresponding target number, additional sessions are allocated equally across all devices.

• The media family attribute specifies the class of storage media, as determined from the media type:

  • tape, tape storage device

  • disk, disk storage device

  • logical, external media device.

• The message attribute specifies the last message from a Backup server regarding a device, such as the progress or rate of an operation.

• The volume name attribute is monitors the mounting and unmounting of volumes for a device.

• The write enabled attribute indicates if writing to the current volume is allowed.

• The volume operation attribute manipulates media volumes currently in the device, through several operations:

  • The Unmount operation releases the device.

  • The Mount operation mounts the loaded volume onto the device.

  • The Verify label operation reads the volume's label, volume's attributes and sets the volume expiration.

  • The Verify write time operation sets the volume write time attribute.

  • The Label or Label without mount operations create new labels for volumes.

  • The Eject operation ejects volumes from the device.

  • The Monitor device operation periodically checks the device to determine whether a volume has been loaded into the device. When a volume containing a readable Backup label is loaded, the volume is listed in the Backup server's media database, and the volume is writable the volume is mounted with write permissions. Otherwise the volume is mounted read only.

• The volume label attribute is set by the Verify label operation and may be an input to the Label operation.

• The volume default capacity attribute is used by the Label operation if the volume current capacity attribute is blank. This attribute enables the override of default sizes when using devices (and/or tapes) with different capacities than the defaults.

• The volume current capacity attribute determines the capacity of a volume during the Label operation.

• The volume expiration attribute specifies a volumes expiration date, which is set by the Verify label operation.

• The volume pool attribute specifies the pool a volume belongs, or has been assigned to.

• The NSR operation attribute specifies the current operation being performed by the device.

• The minor mode attribute reports the current status of a device.

• The statistics attribute reports the statistics on the operation of a device. The statistics include:

  • elapsed, the time of operation

  • errors, the number of errors

  • last rate, the last writing rate

  • max clients, the maximum number of concurrent clients

  • file marks, the number of file marks written

  • rewinds, the number of rewinds

  • files skipped, the number of files skipped

  • records skipped, the number of records skipped

  • current file, the current file number

  • current record, the current record number

  • seek files, the relative number of files being spaced over

  • seek records, the relative number of records being spaced over

  • estimated kb, the total estimated amount read/written on a volume

  • amount kb, the total amount read/written on the volume, in kb

  • file amount kb, the current amount read/written on this file, in kb

  • sessions, the current number of sessions assigned to this device

• The cleaning required attribute indicates whether a device needs to be cleaned. If the value of this attribute changes from yes to no and the value of date last cleaned is not updated then date last cleaned is set to the current time. Backup will set this attribute to yes if the device is scheduled to be cleaned. Then the notification device cleaning required is sent, indicating that a device needs to be cleaned.

• The cleaning interval attribute specifies the amount of time from date last cleaned until the next scheduled cleaning for a device.

• The date last cleaned attribute records the time and day a device was last cleaned.

• The volume block size attribute specifies the block size of a currently mounted volume.

• The volumeid attribute specifies the volume id for a currently mounted volume.

• The access count attribute indicates the number of operations performed on a device since it's configuration as a Backup device.

• The access weight attribute indicates the weight of a single operation performed on a device. Each time a device is used its weight is increased and the less often the device will be selected for new operations.

• The consecutive errors attribute specifies the current number of consecutive errors resident on a device.

• The max consecutive errors attribute indicates the maximum number of consecutive errors allowed before the device will be disabled.

• The operation arg attribute specifies extra parameters about a device operation. Parameters are packed into a string and parsed.

• The volume message attribute indicates the result of the volume's last operation.

• The volume write time attribute indicates the time a save set was first written onto the volume.

• The volume flags attribute indicates new flags for the volume to operated on, during a "Label" or "Label without mount" operation.

• The jukebox device attribute indicates if a media device is in a jukebox

• The unlabeled volume loaded attribute indicates whether a volume loaded into a device has a readable Backup volume label.

• The auto media management attribute indicates whether automated media management for a device is enabled. If the value is set to yes then recyclable volumes loaded into the device may automatically be re-labeled by Backup for re-use and unlabeled volumes loaded into the device may be automatically labeled. A volume is considered to be unlabeled if the volume does not contain a label that may be read by this device. Volumes are considered unlabeled:

  • If a volume contains a label written at a density that can not be read by this device.

  • If a volume contains data written by an application other than Backup and does not have a label recognizable by Backup.

• The logical name attribute specifies the name for a logical device.

• The logical type attribute specifies the type for a logical device.

• The logical family attribute is the family associated with a logical device.

• The connection process id attribute specifies the process identifier that maintains the connection between external media management services and a mounted volume.

• The connection message attribute specifies error messages reported by a process connected to an external media management service.

• The connection status attribute specifies the exit status reported by a process connected to an external media management service.

• The save mount timeout attribute indicates the timeout value from an initial save mount request for a storage node, on which a device resides. If a request is not satisfied, the storage node will be locked from receiving save assignments, for "save lockout" minutes.

• The save lockout attribute indicates the amount of time a storage node will be locked from receiving save assignments.

  The following is an example of a NSR device resource:

  type: NSR device; name: /dev/nrst8; message: writing, done volume name: mars.017; media family: tape; media type: 8mm 5GB; enabled: Yes; write enabled: Yes; read only: No; target sessions: 4; volume label: mars.017; volume default capacity: ; volume current capacity: 5000 MB; volume expiration: "Thu Sep 21 17:23:37 1996"; volume pool: Default; volume flags: ; volume operation: ; volume write time: ; volume block size: 32 KB; volume id: 32449; accesses: 199; access weight: 1; consecutive errors: 0; max consecutive errors: 20; operation arg: ; volume message: ; NSR operation: ; minor mode: idle; jukebox device: Yes; statistics: elapsed = 257572, errors = 0, last rate = 397, max clients = 3, file marks = 22, rewinds = 4, files skipped = 1976, records skipped = 0, current file = 2389, current record = 162, seek files = 0, seek records = 0, estimated kb = 0, amount kb = 6273, file amount kb = 6273, sessions = 1; cleaning required: No; cleaning interval: 2 weeks; date last cleaned: "Tue Apr 11 15:10:32 1995"; auto media management: No; unlabeled volume loaded: No; logical name: ; logical type: ; logical family: ; connection process id: ; connection message: ; connection status: ; save mount timeout: 30; save lockout: 0;