zVT Control Center (ZCC)
The Optica Technologies zVT is a virtual tape appliance created for IBM compatible mainframes. All of the “tape drives” in a zVT are emulated devices where tapes are actually disk files located on a backend storage device attached to one or more zVT nodes. Each zVT node is a 2U rack-mounted server attached to an IBM compatible mainframe using FICON or ESCON channels, and connects to a backend NAS storage device using dual-channel gigabit or 10gb network connections, or to a backend Fibre Channel storage array using dual 8Gbps FC ports.
DTS Software leveraged existing DTS product technology to create the zVT Control Center (ZCC). The product borrows components from SCC Monitor, the Allocation Control Center (ACC), and Easy-Exit. The following table provides information about the ZCC feature set, and contains links to more detailed documentation about each feature.
|Migration||ZCC provides a tape migration tool specifically designed for the zVT.|
|Management||ZCC can manage the zVT devices through the channel interface using a system console and/or TSO/ISPF. TCP/IP Network connectivity to the zVT is not required.|
|Monitor||The product monitors zVTs using the channel or SNMP TCP/IP interface to trap important zVT events, and then notify support personnel via logs, console or TSO messages, email, and/or text messages.|
|OS Device Selection||ZCC can control OS device selection without using an SMS Manual Tape Library (MTL). This feature is similar to the Oracle HSC component, and works in both JES2 and JES3 environments.|
|Load Balancing||ZCC can perform load balancing between nodes in multi-node zVT configurations.|
|JCL Extensions||JCL keyword extensions for zVT Allocation control (IBM z/OS only).|
|Scratch Exits||The product provides dynamically installed scratch exits to keep Tape Management and zVT scratch pools synchronized.|
|Utility Application||The zVT Utility Application allows batch updates to tapes in a zVT. This facility can SCRATCH, UNSCRATCH, ERASE, DELETE and OBLITERATE tapes in a zVT library. The application can also issue commands and execute scripts on the zVT.|
|Japanese OS Support||ZCC has been designed for IBM z/OS, Hitachi VOS3 and Fujitsu MSP systems.|
When a zVT configuration is installed at a customer site, from an operating system point of view, the zVTs are simply groups of tape drives. From an Operations standpoint, the zVT presents several challenges which zVT Control Center (ZCC) has been designed to address:
To streamline a tape migration project, ZCC includes the ZVTCLONE migration utility. Exact copies of tapes are created in a zVT library using the same volume name and device type. The system catalogs and tape management systems are not affected – only the “location” of the tape is changed. If an SMS Tape library is involved in the migration project, the application also manages records in the Tape Configuration Database (TCDB). To aid migration throughput, the ZVTCLONE application can perform up to 99 concurrent tape copy tasks to migrate tapes into a zVT library.
Many installations segregate the TCP/IP network used by the zVT to connect to the back-end storage device; therefore, the operations and support staff have limited access to the web interface used to configure the zVT. However, ZCC can interface to zVT nodes through the channel interface, independent of any network impediments. For command processing, the product temporarily reserves a tape device in a zVT for command execution. As soon as the command completes, the device is released. ZCC can issue zVT commands from:
- operator consoles
- batch jobs
The product can monitor the zVT event log using SNMP. Event triggers can be used to log messages to a data set, SMF records, and/or send messages to operations via the operator console, email or text messages.
The ZCC zVT Allocation interface can be used to control device allocation. If a requested tape resides in a zVT library, only the library devices are eligible for the allocation request. When non-library tapes are requested, ZVTALLOC removes the zVT tape devices from the eligible device list. The interface can also perform unit affinity splits if DD statements try to share the same device, but volumes between the DDs are inside/outside the zVT. Lastly, ZCC identifies the condition where a multi-volume tape dataset uses volumes inside/outside the zVT. In this case, the product uses installation defined rules to handle the conditions. By default, the rules issue a warning message and then terminates the job.
Mainframes have historically been very good at optimizing I/O performance on channel connections. However, installations that have multi-zVT configurations present serious optimization challenges. Due to the number of emulated devices on each zVT controller, and the inability to access the I/O workload on the network connections between the zVTs and backend storage, the network connections for some zVTs can become I/O saturated while others are left idle. This problem is especially prevalent in JES3 installations and zVT configurations that have 1000+ tape devices configured.
The zVT Control Center (ZCC) uses device selection technology developed for the DTS DASD products to enable load balancing across zVTs. ZCC influences the device selection during Allocation. Allocation builds an Eligible Device List (EDL) for the tape request, and ZCC uses a load balancing selection algorithm to spread the tape requests among the zVTs.
Dynamic Scratch Synonyms
ZCC can be used to dynamically assign scratch synonyms to jobs during job initiation. When the ZVTSCR component is started, the product dynamically installs an IGXMSGEX exit – no SMP/E work or IPL is required. Once started, the ZVTRULES member can be used to create policy rules to set the scratch synonym for scratch requests made by jobs. The ZVTRULES have access to the current job and step information, as well as the related security fields. This allows rules to use job names, accounting information, or RACF user/group fields to assign a scratch synonym. The ZCC IGXMSGEX exit provides rules tracing facilities, rule refresh support using a console command, and dynamic start and shutdown capabilities.
When a tape management system (TMS) changes the status of a tape to “scratch”, the TMS system calls an exit that can be used by ZCC to intercept the scratch request. ZCC can immediately notify the zVT that the tape is now scratch. This allows the zVT to have the scratch status synched real-time with the tape management system. The currently supported environments: OAM, IBM RMM, and CA-1.
ZCC provides a wide range of benefits that will ultimately allow installations to more effectively install, implement and manage the zVT. This will be accomplished by providing:
Robust Command and Monitoring Interface
- Modern, efficient and familiar interface
- ISPF/TSO, z/OS system console and batch jobs
- Capture zVT events via an SNMP
Advanced Intelligent Device Selection
- Advanced Allocation Control ensures proper device selection
- NO JCL changes required
- Eliminates the need for OAM or SMS management of zVT tapes
- Provides policies for scratch, multivolume and unit-affinity requests
Efficient Transition via Automated Migration Manager
- Automates and manages the migration of tape libraries
- Unique ‘cloning’ technology for maximum accuracy & effectiveness
- NO updates to TMS required
- Provides simplicity to complex issues
Load Balancing Optimization
- Optimizes performance for multi-node zVTs
- Automated via a device selection algorithm
The marketing literature and webinars are available to all visitors. The product manuals are only available to registered customers and companies trialing DTS products – login is required. To request authorized access, please complete the Registration form. DTS customer support will review your request. Upon approval, you will receive access notification by E-mail within one business day.
|Mar 17 2016||102.38 MB||57 Minutes|
|Mar 27 2012||76.21 MB||51 Minutes|
|zVT Control Center (ZCC) User’s Guide||May 24 2018||4.40 MB|
|Product Installation Guide||Nov 01 2018||1.04 MB|
|Rule Language Programming Guide||May 24 2018||1.55 MB|
|SCC Messages Manual||Nov 15 2018||1.02 MB|
In mid-2015, the DTS distributor in Japan (CLC) asked for information about a new virtual tape device called the zVT. After reading through the marketing material, DTS contacted Optica Technologies about the possibility of a business collaboration. The response was very favorable, and DTS visited the zVT development group in August 2015. After developing the device interfaces to the zVT, DTS ported the DCC product to create the zVT Control Center (ZCC). The new product was released in February 2016.