In the past I’ve seen that people are asking for a TSM backup to /dev/null. It’s also a request on the ADSM.ORG forum and the ADSM-L mailing list. A TSM backup to /dev/null appears to be a myth. Or is it?
This procedure used to be available for customers through the TSM support site. However, it looks like this procedure is not published anymore. There is no mention of it at all in the Administrator’s Guide or Administrator’s Reference. So, this must be considered as undocumented, but it is possible – and although not common knowledge, it might be very interesting for TSM administrators for testing and troubleshooting purposes. I mean, even if you don’t have the storage, you now can emulate DBB’s, clients backups, backup stgpools, etc. All the processing from a TSM client/server perspective still happens, but the actual data is not stored.
“This IBM® Redbooks® publication provides best practice guidance for planning, installing, and configuring the IBM TS7600 ProtecTIER® family of products. This guide provides all the latest best practices for using ProtecTIER Software Version PGA 3.3.x and the revolutionary and patented IBM HyperFactor® deduplication engine, along with other data storage efficiency techniques, such as compression and defragmentation.”
“This book discusses implementation of the data protection solution of IBM ProtecTIER running in a Tivoli Storage Manager environment. It walks readers through the process of planning, setting up, and configuring Tivoli Storage Manager in a ProtecTIER environment. We provide guidance, hints and tips, and trouble shooting for implementing Tivoli Storage Manager with ProtecTIER, backup and restore scenarios, and explain the differences in replication and deduplication in ProtecTIER versus Tivoli Storage Manager implementations. Also provided are disaster recovery approaches which focus on the ProtecTIER Virtual Tape Library (VTL) interface, with some discussion as a File System Interface (FSI).”
The previous TSMBLOG.org article IBM ProtecTIER single-stream performance talked about the pitfalls of aggregated performance vs. single-stream performance. It also lists the single-stream performance for the different PT models (DD3, DD4 and DD5). It was stated that the theoretical throughput of a ProtecTIER DD3 single-stream backup is 60 MB/s. But in a real-world scenario we were unable to get even close to that number. The TSM4VE Full VM backups only got to 20-25 MB/s. After tuning and tweaking, the reported 60 MB/s was reached.
This follow-up article will describe the changes that were made to get there. But keep in mind, all the comments regarding “Full system” performance vs. “Single-stream” performance in the referenced article do still apply. The information provided here is just about how to get to that much required maximum single-stream speed.