Mixing LTO drives and media in a library
When you mix different generations of LTO drives and media, you must consider the read/write capabilities of each generation. The preferred method is to configure a different device class for each generation of media.
About this task
| Drives | Generation 1 media | Generation 2 media | Generation 3 media | Generation 4 media | Generation 5 media | Generation 6 media | Generation 7 media | Generation M8 media | Generation 8 media |
|---|---|---|---|---|---|---|---|---|---|
| Generation 1 | Read/write access | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| Generation 2 | Read/write access | Read/write access | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| Generation 3 | Read-only access | Read/write access | Read/write access | n/a | n/a | n/a | n/a | n/a | n/a |
| Generation 4 | n/a | Read-only access | Read/write access | Read/write access | n/a | n/a | n/a | n/a | n/a |
| Generation 5 | n/a | n/a | Read-only access | Read/write access | Read/write access | n/a | n/a | n/a | n/a |
| Generation 6 | n/a | n/a | n/a | Read-only access | Read/write access | Read/write access | n/a | n/a | n/a |
| Generation 7 | n/a | n/a | n/a | n/a | Read access | Read/write access | Read/write access | n/a | n/a |
| Generation 8 | n/a | n/a | n/a | n/a | n/a | n/a | Read/write access | Read/write access | Read/write access |
Example
If you are mixing different types of drives and media, configure different device classes: one for each type of media. To specify the media type, use the FORMAT parameter in each of the device class definitions. (Do not specify FORMAT=DRIVE.) For example, if you are mixing Ultrium Generation 5 and Ultrium Generation 6 drives, specify FORMAT=ULTRIUM5C (or ULTRIUM5) for the Ultrium Generation 5 device class, and FORMAT=ULTRIUM6C (or ULTRIUM6) for the Ultrium Generation 6 device class.
In this example, both device classes can point to the same library with Ultrium Generation 5 and Ultrium Generation 6 drives. The drives are shared between the two storage pools. One storage pool uses the first device class and Ultrium Generation 5 media exclusively. The other storage pool uses the second device class and Ultrium Generation 6 media exclusively. Because the two storage pools share a single library, Ultrium Generation 5 media can be mounted on Ultrium Generation 6 drives as they become available during mount point processing.
If you mix older read-only media generations with newer read/write media in a single library, you must mark the read-only media as read-only and check out all read-only scratch media. For example, if you are mixing Ultrium Generation 4 with Ultrium Generation 6 drives and media in a single library, you must mark the Generation 4 media as read-only. In addition, you must check out all Generation 4 scratch volumes.