Troubleshooting
Problem
This document provides information on using parallel support to process an existing control group.
Resolving The Problem
When to Use Parallel and Concurrent Saves
Due to i5/OS restrictions, you can gain the greatest benefit by designing a strategy that combines concurrent and parallel backup support. You should, if possible, use concurrent backups to reduce backup windows for objects, which can only be saved by using serial mode; such as system data, security data, configuration data, or folders and documents. Use parallel support when you want to reduce your backup window for large libraries and objects, large directories and files, large spooled files, or large numbers of these objects. In cases when saving large amounts of small data, parallel support is not the ideal choice and may negatively impact save performance.
To use parallel support in an existing control group, you should follow these steps:
1. At the command line, type WRKCTLGBRM to get to the Work with Backup Control Groups display. Then take Option 8 (Change attributes) in front of the control group you want to work with. This takes you to the Change Backup Control Group Attributes display.
2. At the Parallel device resources parameter, indicate the minimum and maximum number of device resources you want to allocate to the processing of this control group. In this example, we instructed BRMS to save the contents of the SAMPLE control group to a minimum of two devices and a maximum of four devices.
3. Press Enter to save and return to the Work with Backup Control Groups display.
Due to i5/OS restrictions, you can gain the greatest benefit by designing a strategy that combines concurrent and parallel backup support. You should, if possible, use concurrent backups to reduce backup windows for objects, which can only be saved by using serial mode; such as system data, security data, configuration data, or folders and documents. Use parallel support when you want to reduce your backup window for large libraries and objects, large directories and files, large spooled files, or large numbers of these objects. In cases when saving large amounts of small data, parallel support is not the ideal choice and may negatively impact save performance.
To use parallel support in an existing control group, you should follow these steps:
1. At the command line, type WRKCTLGBRM to get to the Work with Backup Control Groups display. Then take Option 8 (Change attributes) in front of the control group you want to work with. This takes you to the Change Backup Control Group Attributes display.
2. At the Parallel device resources parameter, indicate the minimum and maximum number of device resources you want to allocate to the processing of this control group. In this example, we instructed BRMS to save the contents of the SAMPLE control group to a minimum of two devices and a maximum of four devices.
3. Press Enter to save and return to the Work with Backup Control Groups display.
NOTE: If at V5R4 or earlier, the control group is now defined to save in parallel, and there is no further action necessary. Starting at V6R1, parallel processing can also be defined at the backup entry level; therefore, additional settings might be considered:
4. At the Work with Backup Control Groups display, type Option 2 (Edit entries) next to the control group you are editing and press Enter.
5. Press F11 three times to bring you to the Advanced backup controls panel.
6. In the Parallel Type column, enter the type of parallel you would like to be used for the backup item. The following are definitions of each type:
4. At the Work with Backup Control Groups display, type Option 2 (Edit entries) next to the control group you are editing and press Enter.
5. Press F11 three times to bring you to the Advanced backup controls panel.
6. In the Parallel Type column, enter the type of parallel you would like to be used for the backup item. The following are definitions of each type:
| o | The value *DEFAULT is the default value. BRMS decides the best Parallel Type to use on the backup item. If the backup item does not support parallel, then a non-parallel backup is performed. |
| o | The value *PARALLEL specifies a parallel save format backup. This format spreads each object across multiple resources. A *PARALLEL type cannot be specified for the following backup items: a. *ALLUSR b. *ALLPROD c. *ALLTEST d. *ASPnnn |
| o | The value *SERIAL specifies a multiple-library parallel format. This format spreads libraries across multiple resources. Each library is backed up to a single resource. A *SERIAL type cannot be specified for the following backup items: a. *LNK lists b. *EXIT containing a SAVDOMBRM command c. *LINK d. *LNKOMTONL e. *LNKOMTLTS f. *LTSOMTONL |
| o | The value *NONE specifies a parallel backup is not being requested. This will force BRMS to use a single resource. |
Notes:
| 1. |
Parallel saves can only be done on drives that can write at the same density.
|
| 2. |
When using multiple tape libraries for parallel saves, the following needs to be done:
a. *MEDCLS needs to be used for the Device Backup devices . . . . . . . . . . . . . *MEDCLS Parallel device resources: Minimum resources . . . . . . . . . . xx Maximum resources . . . . . . . . . yy b. Tape libraries need to have drives that support the same density c. Media policy used needs to have *ANY for the storage location |
| 3. |
Parallel saves can also be done when using the SAVLIBBRM, SAVOBJBRM, and SAVBRM commands.
|
| 4. |
When *DEFAULT is used for *ALLUSR, *IBM or generic libraries, BRMS will save libraries using multiple drives concurrently,
also known as Parallel-Serial saves or library spreading. |
For more information on parallel support and restrictions, refer to the Backup, Recovery, and Media Services for i5/OS user manual:
More information regarding BRMS, please refer here:
BRMS Wiki
BRMS Wiki
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Historical Number
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Document Information
Modified date:
06 December 2024
UID
nas8N1012281