Possible values of the parameter are strings in one of the following forms:

• Physical disk
  • "/dev/sd<L>" where "L" is letter, for example "/dev/sdb"
  • "/dev/disk/by-id/..." - addressing by the disk ID, for example "/dev/disk/by-id/ata-ST1000DM003-9YN162_S1D01QJ4"
  • "/dev/disk/by-label/..." - addressing by the disk label, for example "/dev/disk/by-label/MyStorage"

  • "/dev/disk/by-uuid/..." - addressing by the disk UUID, for example "/dev/disk/by-uuid/0e808a2f-cdd3-4944-a245-f729ffd73882"
    Please note that existing data on such a disk may be destroyed, depending on how it is used in the emulator.

"/dev/sd<L>" addressing is not persistent, so it is strongly recommended to use "/dev/disk/by-id/wwn-*" syntax instead to refer the disk by its WWID - especially in the enviroments utilizing FC and SAN storages.

 These disks must not be formatted by the host OS.

Example:

set PKA container[0]="/dev/disk/by-id/ata-ST1000DM003-9YN162_S1D01QJ4"

It is also possible to use not a whole disk, but previously created partitions on it. In this case the syntax is the following: "/dev/sd<L><N>" where N is the number of partition to be used. 

Example:

set PKA container[0]="/dev/sdc1"

.

• Multipath disk
  • "/dev/dm-<N>" 
  • "/dev/mapper/mpath<N>" 
  • "/dev/mapper/disk<N>" 
    Be careful not to destroy all the information from the disk dedicated to CHARON-AXP by mistake.  

    These disks must not be formatted by the host OS.

    Example:

    set PKA container[100]="/dev/dm-0".
    .
    

• Loop (virtual block) devices

  • "/dev/loop<N>"

    Example:
    set PKA container[200]="/dev/loop0"

    
    

• Direct mapping to some SCSI device, for example, a SCSI disk, tape reader or tape changer
  

  • "/dev/sg<N>" (do not use /dev/st<N> devices, only /dev/sg<N> for tape drives)
    

    Example:

    set PKA container[300]="/dev/sg0"

    .

• CD-ROM device
  • "/dev/sr<N>"
  • "/dev/cdrom" 

  • "/dev/cdrom<N>"

    Example:
    

    set PKA container[400]="/dev/sr0"

    .

• ISO file for reading distribution CD-ROM image
  • [<path-name>/]<file-name>[".iso"]
     Mapping may also include the full path (recommended), for example: "/my_disks/vms_distributive.iso"

    Example:

    set PKA container[600]="/my_disks/vms_distributive.iso"

    .
• File representing a physical disk of the HP Alpha system (disk image)
  • [<path-name>/]<file-name>[".vdisk"]
    These files can be created from scratch with "mkdskcmd" utility. Data and OS disk backups are transferred from the original system via tapes or network and restored into these container files.   

    Mapping may also include the full path, for example: "/my_disks/my_boot_disk.vdisk"

    Example:

    set PKA container[401]="my_dka401.vdisk"
    
    
  • File representing the tape (tape image)
    • [<path-name>/]<path-name>"\"]<file-name>".vtape"
      

      These files are created automatically. 

      Mapping may also include a full path (recommended), for example: "/my_tapes/backup.vtape" 
      
      If the "CHARON Guest Utilities for OpenVMS" (CHARONCP) package is used the syntax is different. Please read the corresponding chapter.
      

      Example:

      set PKA container[500]="my_mka500.vtape"

      How the Emulator Maps Guest-OS Operations to the Virtual Tape Drive:

      Guest-OS operations	Emulator Action
      Open device for reading	Create a container file if none exists. open for reading and lock container file
      Open device for writing	Create a container file if necessary; open for writing and lock the container file
      Unload (eject) tape from drive	Close a container file if open and unlock it - this allows copy/move/delete operations on CHARON host

      Please note:

      The container file associated with a virtual tape drive can be compared to the tape cartridge used in a physical tape drive. Both store the data written to the tape device by the guest OS.

      The size of virtual tape container files is limited only by space available in the emulator host file system.

       Prerequisite to the examples below: a virtual tape device has been configured in the CHARON configuration file and it is not in use by the guest OS.

      To perform backup:

      1. The tape device may be issued the "unload" command and the container-file moved/deleted to insure proper status 
      2. Initialize the tape device using standard guest OS procedure.
      3. Perform backup.
      4. Issue "unload" command to the tape device in the guest OS.
      5. On the emulator host, move the *.vtape container file containing backup data for storage or further backup.

      To restore from a backup:

      1. The tape device may be issued the "unload" command to insure proper status.
      2. On the emulator host, move or copy a *.vtape container file containing backup data onto the filename specified in the CHARON configuration file.
      3. Perform restore.
      4. Issue the "unload" command to the tape device in the guest OS.
      5. Delete or move the container file in preparation for the next vtape operation.

      CHARON does not support muti-volume backup for tape images. If some mutli-volume set (in form of tape images) has to be restored it is recommended to configure several tape drives in CHARON configuration file, assign each tape image to each tape drive and use them in the following way (OpenVMS example):

      $ BACKUP MKA100:BACKUP.BCK,MKA200,MKA300,MKA4000/SAVE_SET DKA0:...

      
      

This parameter is initially not set, thus creating NO storage elements on the controller.

This formatted string value specifies the explicit geometry of the disk storage element. This parameter is not applicable to tape storage elements.

The string format is <X>”/”<Y>[“/”<Z>] or <X>”,”<Y>[“,”<Z>][“,”<B>] where:

• X corresponds to the number of sectors per track
• Y corresponds to the number of tracks per cylinder
• Z corresponds to the number of cylinders on the unit. If omitted, Z is calculated based on X, Y and the total number of sectors on the unit that reflects the size of the disk storage element. This is an optional parameter.
• B corresponds to the total size of the disk (in blocks) reported to the guest OS. If omitted it is calculated automatically. This is an optional parameter.

If this parameter is not set, CHARON-AXP will configure the geometry based on the most probable disk type.

Initially not set.

Please note:

It is possiblle to specify each parameter independently of another one. The following syntax is used for that:

set PKA geometry[300]="*,*,*,16777210"

The syntax described above is applicable only to disk storage elements. If the container is a tape image, the following format is used instead:

Syntax:

"<image-size>[, <early-warning-zone-size>]"

where:

• image-size corresponds to the tape size in MB
• early-warning-zone-size corresponds to the size (in KB) of the space left on the tape when a warning to the OS is issued. If omitted, 64K is assumed.
  

Example:

set PKA geometry[603] = "255/255"