Operating System pane: Disks page

Use the Disks page to view information on the disks that hold the operating system, installed applications, or other data directly associated with the operating system. You can also change the name and description for the disks.

Introduction

The Disks field on the left of the page provides a list of the disks that hold the operating system, installed applications, or other data directly associated with the operating system. The information displayed in all other fields on the disks page applies to the disk selected in this field.

Fields

Disks
Select the disk for which you want to view information. The content of the Disks page changes according to the disk you have selected in this field. When disk information is displayed for an operating system instance, a leading asterisk (*) identifies a disk as a boot disk.
Name
Name that z/VM Center uses for the disk. The default is made up of these parts:
  • The z/VM system ID
  • A z/VM user ID; to z/VM, the z/VM virtual server is the guest virtual machine with this ID
  • The virtual device number that operating systems on the z/VM virtual server use to access the disk

You can change the default by typing any name that is meaningful to you. Changing this name does not change the IDs or device numbers used by z/VM.

Virtual Disk
Virtual device number used by the operating system instance on the z/VM virtual server to access the disk. You cannot edit this field.
Access mode
Disk access mode, for example:
MR
Multiple-write access. The z/VM control program establishes write access, unless another user has an existing write, stable, or exclusive mode access to the disk. If a previous write or stable access exists, z/VM establishes read-only access. If an exclusive mode access exists, access is denied.
RR
Read-only access. The z/VM control program establishes read access unless a another user has an existing exclusive mode access.

For information on other access modes, refer to z/VM® CP Command and Utility Reference, SC24-6081. You cannot edit this field.

Boot Disk
When disk information is displayed for an operating system instance, this check box is selected if the disk has been declared as a boot disk. You cannot edit this field.
Owned by
The z/VM user ID of the guest virtual machine that owns the disk. You cannot edit this field.
as
The virtual device number of the disk used by the guest virtual machine that owns the disk. This can differ from the virtual device number used by the z/VM virtual server on which your operating system instance is installed. You cannot edit this field.
Device Type
Disk device type. You cannot edit this field.
Volume ID
The volume label that identifies a physical disk independent of the device number with which it can be accessed. In mainframe terminology, this label is usually referred to as "VOLSER". You cannot edit this field.
Start
For z/VM minidisks only: Specifies the location of the first cylinder or block on the disk device where the minidisk resides. A minidisk is a logical subdivision (or all) of a direct access storage device (DASD) that has its own virtual device number. You cannot edit this field.
Range
The disk size in cylinders or blocks. You cannot edit this field.
Units
The unit for the range. Can be cylinders or blocks. You cannot edit this field.
Organization
Disk architecture. For example, the organization can be:
Fixed-Block Architecture
Fixed-Block Architecture (FBA) is a DASD data storage architecture in which the data is stored in fixed-length blocks. Each block is addressed by a block number relative to the beginning of the particular disk.
Count-Key-Data
Count-Key-Data (CKD) is a DASD data storage architecture in which the data is stored in variable-length records. Each record contains a count field, usually followed by a key field, followed by the actual data of the record. The count field contains the cylinder number, head number, record number, and the length of the data. The key field contains the record’s key (search argument).
Extended Count-Key Data
Extended Count-Key Data (ECKD) is a DASD data storage architecture specifically designed to support nonsynchronous DASD control units.

You cannot edit this field.

Blocks
Depends on the organization:
  • For fixed-length block architectures the size of the disk in blocks.
  • For CKD architectures the block size is assumed to be 1, therefore the value in the Blocks field is equal to the disk size in bytes.

For both cases, the disk size can be calculated with the formula: Blocks × Size.

You cannot edit this field.

Size
Depends on the organization:
  • For fixed-length block architectures the block size in bytes.
  • For CKD architectures the block size is assumed to be "1".

For both cases, the disk size can be calculated with the formula: Blocks × Size.

You cannot edit this field.

Description
Optional: You can type a description of the disk in this field. You can edit and extend an existing description.
Save
Saves all changes you have made on any of the notebook pages.
Refresh
Refreshes all fields on all notebook pages with their current values and discards any changes you have not already saved.
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