HP 3000 Manuals

STORE and TurboSTORE/iX Manual

Preparing Tape and DDS Devices 

Prepare your backup devices by mounting the first media in the stack near
each device onto that device.  Follow the instructions in Chapter 3,
"Preparing Storage Devices," for mounting backup media.

After mounting the media, check the console for a message telling you
that the volume has been mounted.  For example:

     14:47/31/VOL (Unlabeled) mounted on LDEV#8

Note the backup drive's logical device (LDEV) number.  (The LDEV number
is 8 in the example above.)  You may need it to answer a backup request
later.

Single Tape Devices 

When you store to a single backup device (magnetic tape or DDS), files
are copied one file at a time.  When the backup media is full, it
automatically rewinds then prompts you to load new backup media.  When
the second unit of backup media is loaded, STORE continues writing files
until all of the qualified files are stored or another unit of backup
media is needed.  If you are storing many files, or files that are
particularly large, you will have to individually load several units of
backup media onto the single device.

Figure 3-7  illustrates a single-device backup.


          Figure 3-7.  Single-Device Backup 

The FILE command assigns a file name to a backup device according to its
logical device number or its device class.  For example, the FILE command
below assigns the file name T to the device with LDEV 8:

     :FILE T;DEV=8 

To store files to only one device, backreference that device in your
STORE command.  For example:

     :FILE T;DEV=TAPE 

     :STORE @.OPERATOR.SYS;*T 

Using one or more FILE commands is recommended, especially when your
system is configured to automatically allocate devices (autoreply) or
when you are using multiple backup devices.


NOTE  If auto reply is not enabled on the backup device designated, a
      reply from the console is necessary to allocate that device for a
      STORE process.  See Chapter 7, "Handling Media Requests," for more
      information.


The FILE command below assigns the file name BACKUP to the device with
the device class name TAPE.

     :FILE BACKUP;DEV=TAPE 

Using the backup device's logical device number is a more exact way deto
assign a file name to a particular device.  There is only one device
defined as LDEV 8 on your system.  However, several devices may be
assigned the device class TAPE. When you use device classes to name
backup devices, STORE asks you to assign a logical device number to each
file name with a backup request.

FILE Commands for Automatically Allocated Devices.     

In order to have devices automatically allocated to the backup, you must
assign a different file name for each backup device allocated; use an
LDEV number or a unique device class for each FILE command you use, one
for each device.

Refer to Chapter 7, "Handling Media Requests," for a description of
automatically allocated devices.

Multiple Tape Devices 

TurboSTORE allows the use of multiple devices for backup processes.
Multiple devices are identified as a pool of available devices.  When you
store to multiple devices, the devices must have similar characteristics;
different device types are not allowed.  The device characteristics that
must be identical are:

   *   All devices must be local.

   *   All devices must have the same density.

   *   All devices must have the same record size.

   *   All backups must be either labeled or unlabeled; there cannot be a
       mix.

   *   All backup devices must be either DDS-format or magnetic tape or
       magneto-optical; there cannot be a mix.

Multiple devices can be used as:

   *   Sequential devices.

   *   Parallel devices.

   *   Parallel device pools.

Using Tape Devices Sequentially.     

With sequential backup devices, when the first backup on the first backup
device is filled, it immediately begins writing files to a second backup
on the second backup device and the first backup rewinds.  When the first
backup is rewound, you can unload it and prepare the drive with a new
backup.  You do not lose time while the first backup is rewinding nor
while you are loading a new backup.

When the backup on the last sequential device is filled, the process
returns to the first device.  It continues cycling through all the
devices in the device pool until all of the specified files are stored.

Figure 3-8  illustrates a sequential device backup.


          Figure 3-8.  Sequential Backup 

Use the FILE command to give each device a file name that reminds you of
its position.  Then use the STORESET parameter in a STORE command to
reference the multiple devices.  For example, to store files to three
sequential devices, use the following set of commands: 

     :FILE SEQ1;DEV=7 
     :FILE SEQ2;DEV=8 
     :FILE SEQ3;DEV=9 
     :STORE @.@.@;;STORESET=(*SEQ1,*SEQ2,*SEQ3) 

The above STORE command copies all system and user files to three
sequential devices.  The parentheses surrounding backreferenced file
names group the devices into a device pool. 


NOTE  You do not backreference the file name of a backup device
      immediately after the name(s) of the file(s) you are storing when
      you use the STORESET parameter.  Instead, you must use a
      placeholder for the missing parameter normally supplied when using
      a single backup device.  The placeholder is provided by the use of
      ";;" in the STORE command.


If you gave the backup devices a single file name such as:

     :FILE T;DEV=TAPE 

enter the following STORE command to copy files to a set of three
sequential backup devices:

     :STORE @.@.@;;STORESET=(*T,*T,*T) 


NOTE  Only unlabeled backups can be used for a sequential device backup.


Using Tape Devices in Parallel.     

With parallel devices, you have the capability of reducing backup time by
storing different files on different devices at the same time.  When you
store files to a set of parallel devices, the files are grouped before
the store begins and then copied to multiple devices simultaneously.  For
example, when you have three parallel devices, your files are partitioned
into three subsets.  Files in the first subset are copied to the first
backup drive, the files in the second subset are copied to the second
backup drive, and so on.  When a backup is filled, you are prompted to
mount another backup on that drive.

Depending upon the characteristics of your files and your backup devices,
storing files to parallel devices usually saves more time than using
sequential devices.

Figure 3-9  illustrates a parallel device backup.


          Figure 3-9.  Parallel Backup 

Currently, the TurboSTORE/iX II system configurations support a maximum
of 16 parallel backup devices.  The actual speed of performance depends
on the system, disk configuration and the backup devices used.

To store files to a set of four parallel devices, the following set of
commands can be used:

     :FILE PARA;DEV=7 
     :FILE PARB;DEV=8 
     :FILE PARC;DEV=9 
     :FILE PARD;DEV=11 
     :STORE @.OPERATOR.SYS;;& 
     :STORESET=(*PARA),(*PARB),(*PARC),(*PARD) 

If you gave the backup devices a single file name such as:

     :FILE T;DEV=TAPE 

enter the following STORE command to copy files to a set of four parallel
backup devices:

     :STORE @.@.@;;STORESET=(*T),(*T),(*T),(*T) 

Describe parallel devices in the STORESET parameter by enclosing each
backreferenced device file name within parentheses.  Use commas to
separate devices.

Using Parallel Device Pools.     

Parallel device pools are multiple sets of sequential devices used in
parallel.  Using parallel device pools is often the most efficient way to
store a large set of files when you have several backup devices.
Parallel device pools give you the advantages of both parallel and
sequential devices.  You copy file subsets to different devices
simultaneously, and can have another sequential device ready when the
media is filled in any device pool.

Figure 3-10  illustrates a parallel device pool backup.


          Figure 3-10.  Parallel Device Pools 

Up to eight serial backup devices are currently supported within a
parallel device pool.  Maximum performance is obtained by using three or
four parallel sets, each consisting of two sequential devices.

To store files to parallel device pools, use parentheses to group the
devices into pools.  Separate the devices in the pool from one another
with commas.  Commas also separate each device pool.  For example, the
following commands copy files to two parallel device pools.  Each device
pool contains two sequential devices.  In the following example, STORE
uses a total of four devices divided into two device pools.

     :FILE PPA1;DEV=7 
     :FILE PPA2;DEV=8 
     :FILE PPB1;DEV=9 
     :FILE PPB2;DEV=11 
     :STORE @.OPERATOR.SYS;;STORESET=(*PPA1,*PPA2),(*PPB1,*PPB2) 

If you gave the backup devices a single file name such as:

     :FILE T;DEV=TAPE 

enter the following STORE command to copy files to a set of parallel
device pools:

     :STORE @.@.@;;STORESET=(*T,*T),(*T,*T) 

MPE/iX 5.0 Documentation