IBM E16RMLL-I Implementation Guide - Page 83
Tape volumes
![]() |
View all IBM E16RMLL-I manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 83 highlights
To avoid limiting your scalability (few environments are static or shrink with regards to the amount of managed data) To avoid building additional complexity into the design and implementation, which will drive the cost of implementation higher Because the price point for libraries and tape drives have fallen significantly in the recent past Two-drive systems allow for quicker reclamation and pool copies and reduced drive outages, but restores coming from tape may be delayed due to other competing tape activity. Systems with three or more tape drives can handle restores from tape occurring while tape reclamation or other tape processing is in progress. As for the number of tape drives, a critical consideration is how quickly you need to restore one or more clients. More tape drives allow you to restore more clients in a given time. Collocation allows as many clients to be restored simultaneously as you have tape drives. If you have stringent restore requirements, collocation and multiple tape drives make sense. You could also consider features like backup sets and logical volume backups for highly time dependent servers to improve their restore window. To calculate the rate of a restore operation, divide the amount of storage to be restored by the sustained data rate of the tape drive (not the instantaneous, or burst, rate) quoted by the manufacturer. If this number does not allow you to meet your service levels, collocation, more tape drives, faster tape drives, a new service level, or another backup strategy may be required. We recommend a minimum of a library with a barcode reader and at least two tape drives for all production-level Tivoli Storage Manager solutions. 2.10 Tape volumes Tape volumes are used to store on-site copies of data, off-site copies of data, and database backups. Additional tape volumes are required because all tape volumes are not filled to capacity. Some volumes are required to stock a scratch pool so that mounts for unused tape volumes can be satisfied. If you are considering backup sets and image backups, you may need to add more tapes to your scratch pool. 2.10.1 On-site volumes You must consider how many tapes you will need to hold your backup, archive, and image data in a specified time frame. Each of those have different expiration Chapter 2. Implementation planning 53
![](/manual_guide/products/ibm-e16rmlli-implementation-guide-3588123/83.png)