Steps to configure auto restore processing and JES2 exits, test the JES2 exit installation and auto restore command.
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Disk Auto Restore Manager (ARM) (Vantage User's Guide 3-16)
Part 1.
Configure for Disk
To configure Disk, review the following sections and perform the tasks as needed.
Run job J08DISK from the Install library
Monitor Subfiles of the Disk Files Data Set
To view and analyze all the subfiles of your Disk Files Data Sets or FILES Databases, you must identify them to Vantage. If you have converted any of your Disk FILES Data Sets to FILES Databases, the name of the FILES Data Set is used to locate the associated FILES Database, that is, you only have to identify FILES Data Set names. The Disk system will dynamically determine the conversion status of the FILES Data Set and access the FILES Databases where appropriate.
Specify all the names within a <FILELIST> section in the CONFIG member of PARMLIB. If the CONFIG member does not exist in your PARMLIB, simply copy it from the SAMPLES library.
To use <FILELIST>, perform the following steps:
For more information about Input Lists, see the chapter "Configuring Multiple Systems" in this guide, as well as the topic "Input Lists" in the Reference Guide.
Note: If you use Disk for Unix System Services, simply include its files data sets as entries as described above, whichever method you decide to use.
Part 2
Auto Restore Processing
Disk provides a native Auto Restore function that initiates a started task, DMSAR, each time a data set under its archive control is referenced. The DMSAR task restores the needed data set while the requester (an online user or a batch job) waits. When the restore is complete, the DMSAR task terminates.
The Auto Restore Manager (ARM) enhances this process in two ways:
ARM can start one or more DMSAR servers, optionally dedicating them to either tape or disk restore work, and leave them active, that is, waiting for more work. These features increase auto restore performance.
ARM also provides a JES2 Exit that makes batch processing more efficient when the batch JCL references archived data sets. Instead of letting the job tie up an initiator while the needed data sets are restored one by one, the JES2 Exit support holds the job, and routes all the needed restores to ARM at once (where multiple servers restore the data sets more efficiently by grouping the restores so that all data sets on an archive volume are processed together, reducing the number of required tape mounts and the time required). ARM then releases the job when all restores are completed. Use of the JES2 Exit is optional but strongly recommended.
ARM provides the system parameter ARDSQTAP which causes outstanding requests for the same tape volume to be processed sequentially by the same DMSAR server. This increases efficiency by reducing the number of tape mounts.
Configure the Basic ARM
To configure the Auto Restore Manager (ARM), use the Config Client to specify the appropriate system parameters.
Activate ARM and Receiver/Dispatcher Components
ARM also requires that the Receiver/Dispatcher component be active. To activate the ARM and the Receiver/Dispatcher components at system startup, uncomment the following statements in the CONFIG member of your PARMLIB, but do not change their order.
*COMP=RCDSP UNCOMMENT IF ARM/ALLOMGR USED (SUARH=Y OR SUPLS=Y) *COMP=ARM UNCOMMENT IF ARM IS USED (SUARH=Y)
Note: If you uncomment the COMP=ARM statement but fail to uncomment the COMP=RCDSP, auto restores will fail because the requests can not be received, and a soft loop will occur at system shutdown, issuing the following message:
VAN0902I Comp=ARM Shutdown in Progress. Waiting for Normal Completion or Forced Termination.
Specify sysparms SUARH (Y) and QUEUE in VKGPAMRS - member VPPD0H contains default sysparms DISK Interface
Run Job J01QFILE from the Install library
Identify ARM to Disk
To identify ARM to Disk perform the following steps:
SYSPROG - Configure the Supplied JES2 Exit
The supplied exit is for JES2 Exit 6, and is implemented as a standard JES2 exit, allowing the scanning of internal text. Before installing the exit, see the IBM manual, System Programming Library: JES2 User Modifications and Macros, to read about JES2 exits and considerations for their use.
To configure the JES2 Exit, do the following:
Test the JES2 Exit
To test the installation of the Vantage JES2 Exit, start Vantage, and then submit a job that refers to an archived data set. Make sure that the job name, program name, and data set name are not excluded by the processing list. The following should take place:
The job is placed in hold status.
Either an existing DMSAR receives the restore request, or, if the maximum number of tasks is not already running, a new DMSAR is started.
After the data set has been restored, the job is released by Vantage.
Disable/Enable the JES2 Exit6 Interface
You can disable the JES2 Exit6 processing in two ways:
Disable the exit within JES2 itself
$T EXIT6,DISABLE
No-op its processing
Rename PARMLIB member ARJES2XT and restart Vantage.
If this member with your exclusion filters is not found, all processing within the exit is bypassed. (System parameter ARJESMBR provides the name of the member with your filters. It defaults to member ARJES2XT. If you use a different member, simply rename it, or change sysparm ARJESMBR to specify a non-existing member.)
To enable the exit again, reverse the process you used above:
Enable the exit within JES2 itself
$T EXIT6,ENABLE
Activate exit processing
Rename the member back to ARJES2XT and restart Vantage.
When the member is found, all processing within the exit will start.
S DMSAR,DMSAR=REMOVE
(if the Disk auto restore hook is already active)
S DMSAR,DMSAR=INSTALL
Auto Restore Command:
Deactivate/Activate ARM
To deactivate ARM for a short period of time, issue the command:
F SAMS,ARM,DRAIN
To reactivate it again (after being drained), issue:
F SAMS,ARM,START
To deactivate ARM permanently:
Specify system parameter SUARH (N)
F SAMS,STOP (to shut the system down)
S SAMS (to start it up again)
Suspend/Resume ARM
To suspend ARM processing of requests for a short period of time, and deallocate the FILES data sets, issue the command:
F SAMS,ARM,SUSPEND
To resume processing of queued/pending requests, issue:
F SAMS,ARM,RESUME
The SUSPEND command frees the FILES data sets such that Disk IXMAINT jobs can perform maintenance. When maintenance is finished, the RESUME command causes Vantage to reallocate the FILES and resume processing the restore requests.
SYSPARMS consideration:
The list of VKGPARMS entries involved to activate DMSAR/ARM processing correctly:
ARDSQTAP (N) - Stack all requests for the same tape together
ARDEDSRV (N) - Separate DASD & tape servers
ARDSKSRV (1) - Controls total number of DASD archive tasks
ARTAPSRV (1) - Controls total number of tape archive tasks
FILES1 (CADISK.FILES) - Specify the production Disk Files data set
MAXTASKS (1) - Maximum of all started tasks combined
SUBSYSN (XAD1) - Identify the Vantage task name to Disk
SUARH (Y) - Activate interface to Auto Restore Handler
SUDMS (Y) - Activate Auto Restore Manager (ARM)
Why it was involved:
ARDSEQTAP - This made DMSAR keep a tape for extended periods of time. At its worst point, every lpar was waiting for hours use one tape a single DMSAR wouldn't release. A corresponding Disk sysparm, DYNUKEEPN was set for the same reason.
ARDEDSRV - This makes both the ARDSKSRV & ARTAPSRV dedicated, resulting in both DSKSRV & TAPSRV settings to take full effect. Since we observed all DMSAR's calling for tape (caused by the FILES1 missing), reduction to a maximum of 1 DMSAR per restore type (2 total) was initially made. To reduce to a maximum of 1, this was switched to N and MAXTASKS (1) took effect.
FILES1 - When not specified, Vantage assumed archive files are stored on DASD. This caused ARDSKSRV to take effect and use tape when an archive was actually on tape. If ARTAPSERV started too, there are the two tapes in use at once.
SUBSYSN - Disk can only specify this name once, since each individual system was uniquely labeled, Disk couldn't 'talk to' ARM. A corresponding change to Disk parm 'SAMSYSNMSAMS' was made pointing to the Vantage default of SAMS.
ARDSKSRV & ARTAPSRV - When ARDEDSRV is Y, this total of these is the maximum number of DMSAR's that will run at the same time. By setting ARDEDSRV to Y, a maximum of 1 DASD based auto restore & 1 tape based auto restore will run at the same time. Switching ARDEDSRV to Y will maintain the '1 tape drive max per system' requirement and improve auto restore throughput by processing dasd based restores independent of the tape based restores.
MAXTASKS - When ARDEDSRV is N, this controls the maximum number of DMSAR's that will run at the same time regardless of whether they are dasd or tape based.
SUARH & SUDMS - Added in many VKGPARMS where they were missing. The default value (N) on either of these deactivates ARM and DMSAR runs independent of Vantage.