HP 3000 Manuals HP 3000 Manuals
GLOSSARY account A collection of users and groups. Each account has a unique name on the system. It is the method used to organize a system's users and files and to allocate use of system resources such as central processor time, online connect time, and file space. Accounts are the principal billing entity for the use of these resources. Every user must specify an account to access the system. backup The process that duplicates computer data to offline media, such as magnetic tape. Backups protect data if a system problem occurs. bad drive The single drive that is a partner of a mirrored pair that has been marked bad by the system because of a disk-related failure. In the repair process, the bad drive is the destination of the copy. batch processing A method of submitting a job for processing. A job, which is submitted as a single entity, can consist of multiple commands such as program compilation and execution, file manipulation, or utility functions. Once submitted, no further interaction between the user and the job is necessary. boot The process of leading, initializing, and running an operating system. The term "booting" is derived from the phrase "pulling yourself up by your bootstraps." crash 1) The unexpected shutdown of a program or system. If the operating system crashes, it is called a "system crash" and requires the system to be rebooted. 2) A head crash or disk crash. This occurs when the read/write heads on a disk drive (that normally ride on a thin cushion of air above the disk) make physical contact with the disk surface, destroying data and the disk track. The extent of damage to the system depends on which disk crashed and how much of the disk was corrupted. A crash of the system disk is serious, since it contains the directory of user files as well as operating system programs, the I/O configuration, and the accounting structure. data recovery The process of using DISCUTIL to recover data from disks that cannot be used by the operating system. DISABLED A mirrored disk state where a disk has failed and is no longer being used. When this occurs, the operator is notified by a console message. disk repair In mirrored disks, disk repair refers to the copying of data from one good disk to its partner (bad disk). This operation takes about twenty minutes and does not interfere with applications running on the system or accessing the volume set. DISCUTIL utility An MPE utility that is used primarily to recover data from disks that cannot be used by the operating system. disk A circular plate of magnetically coated material used to store computer data. A disk may be fixed, removable, hard, or flexible. disk drive A peripheral device that reads information from and writes information to the disk. disk failure A disk-related problem that causes a disk to be unavailable for use. disk pack A set of one or more disk platters stacked inside a plastic cylindrical container. GEN Generation number. A number between 0 and 32,767 used to distinguish different versions of a volume set. good drive The single drive that is a partner of a mirrored pair that has been marked good by the system when compared to its partner. In the repair process, the good drive is the source of the copy. group A group is part of an account that is used to organize the account's files. All files must be assigned to a group; and, within an account, each group has a unique name. Groups are the smallest entity for which use of system resources is reported. A PUB group is designated for each account when it is created. Additional groups are created within the account, as needed, by the account manager. logical device number (LDEV) An LDEV number is assigned to all hardware components of a computer system and is used for identification purposes. LONER A duplicate of a member volume currently online or a volume recognized by MPE as a member volume but without a master volume online. The VSCLOSE command puts all master and member volumes of a set in the LONER state. master volume A master volume is the only volume needed to define a volume set. It contains the configuration data, the root directory, a free space map, file label table, and a volume label with a unique volume set ID for the volume set. MASTER The state of a disk recognized by the system as a master volume. member volume A volume containing a volume label indicating that it belongs to an MPE volume set. It may be used by one or more volume classes. MEMBER The state of a disk recognized by the system as a member volume. mirrored disks Two partner disks that contain exactly the same information. When a write is issued, the write is performed on both disks. mirrored disk states A mirrored disk exists in one of the following states: NORMAL, PENDING, DISABLED, NON-MIRROR, SUSPEND-MIRR, REPAIR-DEST, REPAIR-SRCE, USER, and BACKUP. mountable volumes See nonsystem volumes. mounting The act of making a data storage device accessible. To physically mount the device, you load the media onto the device. To logically mount the device, you tell the operating system which device you want to use, and it allows you access to that resource. NON-MIRROR A mirrored disk state where a disk does not have a partner and is not functioning as a mirrored disk. nonremovable disks Disks that cannot be removed from the disk drive. nonsystem volumes Nonsystem or mountable volumes are member volumes of a volumes set. They do not need to be mounted for the operating system to run. NORMAL A mirrored disk state where two mirrored partner disks are operating, and one is not being repaired. online A system state that means the system is available for use. A split-volume backup occurs while the system is available. PENDING A mirrored disk state where one partner of a mirrored pair is not mounted and the other partner that did mount is not available for use. private volumes See nonsystem volumes. recognizing a disk See mounting. removable disk Disks that can be removed from disk drives and transported to another disk drive. REPAIR-DEST A mirrored disk state that shows which partner is the destination (being copied to) of a repair. REPAIR-SRCE A mirrored disk state that shows which partner is the source (being copied from) of the repair. SCRATCH volume A volume whose data is no longer needed that has been marked as available for a new volume or volume set. The SCRATCHVOL command marks the volume. The UNSCRATCHVOL unmarks the volume without losing any data or label information, provided that the disk has not been written to. split-volume backup The process that duplicates computer data to offline media while the operating system is running. split-volume set A mirrored volume set that has been "split" into user volumes and backup volumes by the VSOPEN command to prepare for online backup. SUSPEND-MIRR A mirrored disk state where a disk does not have a partner and is not functioning as a mirrored disk. system abort See crash. system disk The disk volume, mounted as logical device 1. It contains MPE, I/O configuration information, the accounting structure and file directory, and utilities and subsystems. It also contains an area reserved for virtual memory and may be used to store user files. system master volume The volume of a system volume set that is always named MPEXL_SYSTEM_MASTER. This volume must be mounted for an MPE operating system to be booted and is always mounted on LDEV 1. system volume An MPE system volume set. It contains a bootable system image of the operating system and system configuration on its master volume. It is the only volume needed to load and start the system. It is always mounted and named MPEXL_SYSTEM_VOLUME_SET. UNKNOWN A disk pack without a volume label recognized by MPE/iX. unscratch a volume To make data available on a previously "scratched" volume. See SCRATCH volume. volume A volume is one-disk pack. Each volume is assigned a name for identification and reference. This name must be unique within its volume set. A volume may be a member of one or more classes. volume class A volume class is used to allocate and limit disk space. A volume class is a logical subset or partition within a volume set and can bridge more than one member volume. A volume class is assigned a unique name within the volume set. No more than 255 different classes can exist in a single volume set. A volume can be partitioned by one or more volume classes. volume failure See disk failure. volume management A facility of MPE used to manage disk storage using volumes, volume sets, and volume classes. volume set A set of volumes containing one master volume and up to 255 member volumes. volume states The states that a volume can exist on a system. Accessible: MASTER and MEMBER. Inaccessible: LONER, UNKNOWN, and SCRATCH. VOLUTIL utility The MPE volume utility that provides volume initialization and maintenance, volume label and membership inquiries, and volume space/sector status.