This chapter describes ELS server considerations.
The VM Client is a thin-client and relies on the resources available within an ELS server TapePlex connected through TCP/IP.
Note:
The ELS server must be at release 7.1 or later.The VM Client specifies a server IP address and port number defined in the ELS SMC configuration. Refer to the publication Configuring and Managing SMC for information about how to configure an HTTP server using the SMC HTTP command.
The following is an example of the SMC HTTP command:
HTTP START PORT 4242
Unlike VM/HSC, the VM Client does not allow management of scratch subpools. Instead, scratch subpools are defined and managed on the ELS server.
A tape management system (TMS), such as VM:Tape, cannot use TMI requests to define scratch subpools. A TMS must use existing scratch subpools defined on the ELS server. In the case of VM:Tape, an attempt to define scratch subpools fails yet VM:Tape initialization continues.
The following is an example of VM:Tape initialization:
VMTHSC693I The HSC interface is connecting. VMTHSC000I Sending to VMCLIENT: QCONFIG with wrong length VMTHSC000I Sending to VMCLIENT: QCONFIG with right length VMTHSC000I Sending to VMCLIENT: QDRIVES VMTHSC999I VMCLIENT completed QDRIVES command successfully VMTHSC000I Sending to VMCLIENT: DEFSCR 5 4 VMTHSC697E HSC server VMCLIENT ACSRQ=DEFSCR RC=16 VTCS Management Classes Reason=00001004 VMTHSC721E HSC scratch pool initialization failed. VMTHSC704I The interface to HSC is ready for use.
If VM:Tape attempts to use a scratch subpool that is not defined to the HSC server, the VM Client replies with a nonzero TMI return code and reason code. For example:
VMTHSC000I Sending to VMCLIENT: QSCRATCH TEST
VMTHSC697E HSC server VMCLIENT ACSRQ=QSCRATCH
RC=16 Reason=00008036
VMTHSC698R 'QSCRATCH TEST ' to VMCLIENT failed;
Enter RETRY, CANCEL, or NOARM;; Reply 1
It is the customer's responsibility to keep scratch subpool names and volumes within the subpools synchronized with the VM TMS.
It is highly recommended that you use the VM Client POOLmap command to associate a VTCS management class with a scratch subpool that contains virtual tape volumes (VTVs). When the VM Client receives a TMI request that specifies a scratch subpool name, the VM Client will use the POOLmap management class for selecting and mounting VTVs.
See "POOLmap" for more information about the POOLmap command.
If the VM:Tape configuration contains multiple tape drives and these tape drives are defined in different ACSs within a TapePlex, scratch mount requests will require the installation of a VM:Tape allocation exit. As an example, the configuration may include two 9840C tape drives, one defined in ACS00 and the other defined in ACS01.
To install a VM:Tape allocation exit, complete the following steps:
Copy the SMCVMTAP sample file to VMTAPE's 191 minidisk with a file name and file type of SMCVMTAP EXEC. You may need to modify the VM Client virtual machine ID in this file.
Modify the VMTAPE configuration file to enable the allocation exit. For example:
EXIT ALLOCATE SMCVMTAP EXEC
Modify VMTAPE's PROFILE EXEC to access the VM Client run disk and execute the SMCALLOC EXEC to load the necessary programs into storage. Make sure you include these commands before invoking the VMTAPE startup EXEC. For example:
CP LINK VSMC730A 202 202 RR ACCESS 202 J EXEC SMCALLOC