Tape Storage

When we think about purchasing a car, there are some features and function that are often desired as we compare vehicles:

• The “Need for Speed”


• Top Speed


• Acceleration: How fast can you go 0-60?

• Can your vehicle last the test of time?


• Is it stuck in the shop for days or weeks?

• Am I going to spend an arm and a leg at the gas station?


• Can I contribute to greener technologies?

We can make similar mappings of these attributes to our enterprise storage. The DS8880 is known as a leader in many aspects, whether speed and low latency, even with disaster recovery and copy function, or its high reliability; serving data 24x7 with no down time.

But how do we map fuel efficiency into an enterprise storage subsystem?

The answer is providing technology that improves data center efficiencies. By creating environments that allow users to do things with less cost or allowing them to be able to do more with their existing investment. Data center efficiencies are always a top sought after feature.

Transparent Cloud Tiering (TCT) for DS8880 in collaboration with DFSMShsm provides substantial improvements in efficiencies in the Mainframe z/OS archive space; delivered in two different ways: Reducing DFSMShsm CPU utilization and additional flexibility of cloud storage as a new tier.

Just like savings at the pump.

For decades, DFSMShsm continues to be the leader in archive/backup software for z/OS. Its technology and architecture has also remained virtually unchanged for as long as its leadership. That architecture was built around the concept of using tape volumes as the primary medium. It is also designed to be the primary data mover, reading the data from the disk and writing the data back onto the tape. That means that the data must flow through the server even though the source of the data is the disk and the intended target is the tape device. Lastly, tape has an inherent concept of recycle which, once the tape is full, the valid data must be read from the old tape and written onto a new tape. All of this effort, since it is being done on the Mainframe, requires an inordinate amount of CPU cycles to do all of this processing.

Transparent Cloud Tiering for DS8000 removes these inefficiencies by allowing the DS8880 to directly move data from the disk to an object storage solution. This eliminates the flow of data through the Mainframe. It also removes many of the other tape-centric requirements like recycle.

The end result?

Mainframe CPU savings that are both measurable and substantial. The fuel efficiency of the data center.

Recently, IBM has developed an estimator of CPU savings that can be achieved by using TCT for DS8000 in conjunction with DFSMShsm. The results from this estimator which uses real SMF data from production HSM environments, has shown CPU savings of over 50% on average. This can be significant depending on the amount of data that is migrated and managed by DFSMShsm.

Besides the average savings per day that TCT can bring, information such as data set sizes that are typically being used and current CPU utilization are easily graphed and displayed.

Customers can use the estimator today which is now available for download:

Offloading the data movement portion of the DS8880 allows for DFSMShsm to execute what it’s best at which is policy based life cycle management and tiering of data to the appropriate tier of storage. So far this sounds great, however, acceptance is more difficult if the end users must learn new methodologies, new commands and new ways to use HSM to take advantage.

This is not the case with Transparent Cloud Tiering where the goal was to truly make the transition to the cloud “transparent”. No pun intended.

With TCT for DS8000, the method in which you use HSM is no different than it is today. TCT simply adds a new tier to the original L0, ML1, ML2 paradigm, adding a Cloud tier. Data can move directly from L0 to Cloud without going through ML1 or ML2.

The same commands for migration (HMIGRATE) or an auto migration policy work the same as it does today.

What about recall? Equally transparent. Recall works as it is today in z/OS, by intercepting the browse or edit, recalling the data directly from the cloud object storage to the DS8880, and then offering the data back to the user.

Providing CPU savings to affect data center efficiencies while maintaining the same usability of DFSMShsm as it exists today makes Transparent Cloud Tiering for DS8880 an exciting innovation with immediate client value.




CPU savings are great, but what else?




It was mentioned earlier that TCT delivers data center efficiencies in two ways. One with CPU savings, but what about efficiencies in the cost of archive storage solutions in the data center?

Cloud object storage has been a quick and oncoming train of innovative and potentially cheaper method of storing offline, archive, backup data. Whether by taking advantage of the charge back model and offloading of capital and operating expenses to a cloud service provider or consolidating archive/backups on-premise across the entire estate both Mainframe or Distributed.

Transparent Cloud Tiering for DS8880 allows for a true hybrid cloud model providing a great deal of flexibility with what type of cloud object storage that can be used. Data can be placed on an on-premise private cloud such as IBM’s industry leading IBM Cloud Object Storage, or an off-premise public cloud such as IBM Bluemix. With integration into DFSMShsm, by policy data based on age, importance, security and other criteria, data can be placed on private, public or both. This flexibility is key to ensuring that data is still accessible but most efficiently placed.

Even with the myriad of different cloud storage choices available for TCT to move onto, IBM is taking another step toward merging the worlds of traditional tape and object storage together. Currently in beta, TCT for DS8000 and DFSMShsm now allows you to move objects to a IBM TS7700 Virtual Tape Subsystem.

Imagine the flexibility this provides whereby existing FICON attached ML2 data can reside on the same system as HSM object data from TCT. This leverages the investment into TS7700 to handle non-HSM tape data while taking full advantage of the HSM, CPU reduced, datasets using TCT. All of this with the industry leading GRID protection that the TS7700 provides.

Just like Hybrid and Electric vehicles are taking advantage of fuel efficiency in the new world, Transparent Cloud Tiering for DS8880 and DFSMShsm is going after the same model. There can’t be a better way to use those efficiencies to save money or increase cognitive insights driving the bottom line. Cars and Enterprise Storage Subsystems are not as different as we may all think. If only we could order our storage systems in different metallic shades and add racing stripes.

Transparent Cloud Tiering for DS8000 and DFSMShsm supports the DS8870 and DS8880 platforms, z/OS 2.1, 2.2 and 2.3 including the newly announced z14.

For more information, resources are available online:

• Announcement


• DS8000 transparent cloud tiering


• z/OS DFSMS cloud storage


• z/OSMF cloud storage workflow definition file


• IBM Cloud Object Storage