The scanning step is run for all FSE media in all FSE media pools that are assigned to a specified FSE partition. This step determines the locations of valid and obsolete data on the already closed (full) and still open FSE medium volumes, according to parameters that you define. It then records the scan results to the Resource Management Database (RMDB). The scanning process is performed as a search through the corresponding File System Catalog (FSC), therefore the FSE media themselves are not physically scanned.
The results of the scanning step are used in the copying step. This step copies all selected file generations from the medium volumes being reorganized to open and empty medium volumes in the same FSE media pool. The original volumes are then recycled and finally reinitialized. To reduce the number of drive load and unload operations during the copying step, the data is copied to (open or empty) medium volumes on the same medium, if any exist.
Note that the copying step of the reorganization process is not started until the scanning step has completed, and vice versa.
Before running the copying step, you can review the results of the scan to decide which FSE medium volumes or FSE media you actually want to reorganize. It is only useful to reorganize volumes with a high enough proportion of obsolete data (that is, a high enough percentage of FSE slack space).
During execution of the reorganization process, FSE progressively shows status indicators (such as scanned, in reorg, and recycled) to the medium volumes being reorganized. These indicators help you detect and track the reorganization progress for a particular medium volume. You can display these status indicators at any time with the following command:
fsemedium
The following table depicts the reorganization steps, a description of their tasks, the volume status indicators that are set, and the corresponding FSE jobs.
Reorganization | Step tasks | Status of medium volumes | Job type | |
step |
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|
Step 1: Scanning |
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| [open/full] | FSE reorganizational |
|
|
|
| scan job |
| 1. | Change the status of the FSE |
| |
|
|
| ||
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| partition to in scan. |
|
|
| 2. | Scan medium volumes for |
|
|
|
| obsolete data. |
|
|
| 3. | Write the scan results to the |
|
|
|
| RMDB. |
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|
|
|
|
|
|
|
|
| [open/full], scanned |
|
|
|
|
|
|
| 4. | Change the status of the |
|
|
|
| scanned FSE partition back to |
|
|
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| [enabled/mounted]. |
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|
|
|
|
Step 2: Copying |
|
| [open/full], scanned, in reorg | FSE reorganization job |
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|
|
|
|
| 1. | Copy selected data from the |
|
|
|
| medium volumes being |
|
|
|
| reorganized to open or empty |
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|
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| medium volumes. |
|
|
| 2. | Recycle the reorganized |
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|
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| medium volumes. |
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| [open/full], scanned, in reorg, |
|
|
|
| recycled |
|
| 3. | Reinitialize the recycled |
| |
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| ||
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| medium volumes. |
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|
|
|
|
|
|
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| empty |
|
|
|
|
|
|
Note that if migrations to a particular FSE medium volume occur after the volume has been scanned but before the copying step has been triggered, the scanned status indicator of this volume is removed. The copying step of the reorganization cannot be started for this volume until the volume is scanned again.
108 Managing media