HP 3000 Manuals HP 3000 Manuals
Storing Files to Magneto-Optical Disk
TurboSTORE/XL II with Optical Support, product numbers 36397A and 36398A,
supports the use of the HP Series 6300 Model 20GB/A Direct Access
Secondary Storage (DASS) device. The Model 20GB/A features two
rewritable optical disk drives and 32 rewritable optical disk cartridges.
Use of magneto-optical disk is recommended for daily backup of large
volumes of data. When used in conjunction with TurboSTORE/XL II's low
data compression option, the capacity of the DASS is increased to almost
40 Gbytes of data and the potential backup rate is increased up to 2.8
Gbytes per hour. When used in conjunction with TurboSTORE/XL II's high
data compression option, the capacity of the DASS is increased to almost
64 Gbytes of data.
Preparing for Backup to Optical Disk
When using the Model 20GB/A device, it is important that you ensure that
enough scratched media is mounted before you issue the STORE command.
The media preparation tasks are performed using the Magneto-Optical
Utility (MOUTIL), a utility program provided on the TurboSTORE/XL II
product tape. Use of the MOUTIL program is documented in the
Magneto-Optical Media Management User's Guide (36398-90001).
Determining the Number of Disks Needed.
Each optical disk surface holds approximately 290 MBytes of uncompressed
data (depending on the type of data and assuming there are no bad sectors
on the disk). By comparison, 2400 feet of 1/2 inch tape holds
approximately 140 MBytes of data. Therefore, one optical disk surface is
equivalent to approximately two tapes. If your backup normally takes
four tapes, plan on using two optical disk surfaces.
You can estimate the number of optical disk surfaces needed by dividing
the total amount of disk sectors in use to be stored by 1,187,840.
1. First, use the DISCFREE command to determine the amount of disk
sectors in use on your system. For example:
_________________________________________________________________________________
| |
| :DISCFREE E,101 |
| |
| DISCFREE A.01.03 Copyright (C) Hewlett-Packard 1989. All rights reserved.|
| WED, OCT 31, 1990, 04:59 AM |
| |
| | Configured | In Use | Available | |
| -----------+-------------------+-------------------+-------------------+ |
| |
| TOTALS : |
| Device | 4464384 | 3136672 ( 70%) | 1327712 ( 30%) | |
| Permanent | 3906336 ( 88%) | 3002160 ( 67%) | 904176 ( 20%) | |
| Transient | 3348288 ( 75%) | 134512 ( 3%) | 1327712 ( 30%) | |
_________________________________________________________________________________
DISCFREE
In this example, a total of 3,136,672 sectors are in use.
2. Divide the total number of sectors to be stored by 1,187,840 and
round up to the nearest whole number to determine the number of
disk surfaces required.
3136672 / 1187840 = 2.6 disk surfaces
In this example you would need three disk surfaces.
Specifying the DASS Device
When storing to a DASS device, you do not use file equations as you do
when using tape drives. Nor do you use the STORESET parameter to
backreference the device. Instead, you specify that backup is to be to
the Model 20GB/A through the MOSET parameter of the STORE command.
Specify the LDEV number of the DASS disk drive as a parameter to MOSET.
For example,
;MOSET=(101)
Naming the Backup
You can optionally use the NAME parameter of the STORE command to name
the backup with a name that logically relates the media as being from the
same backup. The name specified must be unique so that it can be found
when restoring files. For example, a monthly backup for September, 1990
on a system called "KING" could be named "MONTHLY.SEPT1990.KING". Note
that the backup name is a three-field name separated with periods. Each
of the three fields can be up to eight alphanumeric characters. If a
backup name is not specified, a default name is created using the time,
date, and system name. For example, "BK1130PM.D23OCT90.KING".
NOTE The backup name must be unique for RESTORE to be able to find it.
If media is removed from the DASS device, use an external label with the
same backup name as you specified with the STORE command.
Storing to a Single DASS Device
The following example illustrates the STORE command to backup files to a
single DASS device with the LDEV number 101.
STORE @.@.@;;MOSET=(101);SHOW;NAME=BK1130PM.D23OCT90.KING
Storing to Multiple DASS Devices
Multiple DASS devices can be used in parallel (sequential use is not
recommended) for backup by specifying each DASS device drive with the
MOSET parameter. For example, to use LDEV 102 and 103 in parallel, the
MOSET entry would be:
;MOSET=(102),(103)
Storing to Sequential DASS Devices.
The following example illustrates the STORE command entry to use two DASS
devices sequentially.
STORE @.@.@;;MOSET=(101,102);SHOW;NAME=BK1130PM.D23OCT90.KING
With this usage, only one drive will be active storing at any given time
while the other drive is swapping media. Since the swap time for media
is very short, this method is not an efficient use of the two DASS
devices.
NOTE Storing to sequential devices is not recommended since it does not
provide any substantial performance gains.
Storing to Parallel DASS Devices.
Storing to parallel DASS devices is the recommended method of using
multiple DASS devices. The following example illustrates the STORE
command entry to use two DASS devices in parallel.
STORE @.@.@;;MOSET=(101),(102);SHOW;NAME=BK1130PM.D23OCT90.KING
With this usage, both drives will be active storing simultaneously.
[REV END]