Managing Common Media Recorded in Different Densities with ACSLS Pools

The following procedure applies to all cases where different tape drives record on a common media, in different densities. Use the following table to apply the procedure to your specific case:

Old Format Drive(s)	New Format Drive(s)
T10000C	T10000D
T9840C	T9840D
LTO 7	LTO 8

Procedure

Identify all LTO data (non-scratch) cartridges in the ACS, and assign them to a LTO 7 pool. Do this before installing LTO 8 drives in an ACS that has LTO 7 drives.

Now you can assign LTO scratch cartridges to either the LTO 7 or LTO 8 pool.
1. Define LTO 7 and LTO 8 media pools using the following command:
  
  define pool pool_id
2. Report all LTO 7 media.
  
  You can do this by using either the display volume command (option 1) or a custom volrpt (option 2), as shown below:
  
  Results write a file.
  - Option 1
    
    Use the display volume command to write the results to a file.
    
    display volume * -media LTO-6.4T > filename
    
    where:
    
    All LTO 7 tape cartridges (media LTO-6.4T) are reported.
    
    filename is the filename to which the output is written. The ACS ID in which the cartridge is located is also listed.
    
    Read the output, selecting cartridges from specific ACS(s), if desired.
    
    If you want cartridges from one ACS, use the -home operand to only select cartridges from this ACS.
    
    display volume * -home acs_id.*,*,*,* -media LTO-6.4T> filename
  - Option 2
    
    Use the custom volrpt for all volumes in the ACS. The results write a file:
    
    volrpt -d -f custom_volrpt_file -a acs_id > filename
    
    where:
    
    custom_volrpt_file is the filename specifying the fields reported in a custom volrpt. The following fields are reported:
```
VOLUME_ID      6   2
MEDIA_TYPE     7   2
VOLUME_TYPE    4   2 
```
    acs_id is the ID of the ACS that you are managing.
    
    filename is the filename to which the output is written.
  Read the output, selecting only the volumes with a media type of LTO-6.4T.
3. Assign the selected volumes to the appropriate pools.
  
  Assign all non-scratch (VOLUME_TYPE = D) cartridges to the LTO 7 pool using the following command:
```
set scratch off pool_id vol_id
```
  Assign the scratch cartridges (VOLUME_TYPE = S) to either the LTO 7 or LTO 8 pools using the following command:
```
set scratch pool_id vol_id
```
After the LTO 8 drives are installed, use the pools to mount cartridges on compatible tape drives.

Again, cartridges written at LTO 7 recording density can be read by either LTO 7 drives or LTO 8 drives.

The following commands can be used to identify, select and mount cartridges from the pool appropriate for an LTO 7 or LTO 8 drive. Use the pools to ensure you are mounting cartridges on the correct drive.

Note:

If you want to mount a scratch cartridge on the correct drive type, follow procedure A. If you want to mount a non-scratch cartridge with data already recorded on it, follow procedure B.

Procedure A - Mounting Scratch Cartridges
1. Query drive(s) to identify drive types.
```
query drive drive_id | all  
```
2. Identify the correct pool (media type) for the cartridges to be mounted on the desired drive.
3. Mount scratch cartridges to a drive from the specified pool.
```
mount * drive_id pool_id
```
Procedure B - Mounting Non-scratch Cartridges
1. Display the status of drives compatible with a cartridge.
```
display volume vol_id -f pool 
```
  The pool for this volume is displayed.
2. Identify a compatible drive using the query command.
```
query mount vol_id
```
  Drives compatible with a cartridge are displayed.
  
  Select the correct drive type before mounting the cartridge. This query command returns both LTO 7 and LTO 8 drives (because both drive types are compatible with LTO-6.4T media).
  
  Use drive type to separate T9940As from T9940Bs.
3. Mount the cartridge on the selected drive.
```
mount vol_id drive_id
```
When all of the data on the cartridge has expired, you can migrate the scratch cartridges to the pool for the new recording density. Because LTO 7 and LTO 8 drives can re-initialize cartridges in their density, scratch cartridges can be reassigned to a different pool.
```
set scratch pool_id vol_id
```
After all LTO 7 drives are converted to, or are replaced by LTO 8 drives, all LTO-6.4T media can be used by LTO 8 drives.