DB2 Server for VSE & VM: Operation

Common Parameters

The following table contains initialization parameters common to both the VSE environment and the VM environment. Initialization parameters specific to each system follow.

Parameter	Default	Description
ARCHPCT=n	80	Archive Percent n is a decimal value indicating percentage. When the log is n percent full, the database manager begins an archive process, prompting the operator to mount the required tape. The n can be any number from 10 to 99. This parameter is used only when LOGMODE=A or when LOGMODE=L is specified. When LOGMODE=A, a database archive is started when the ARCHPCT value is reached. When LOGMODE=L, a log archive is started instead of a database archive. For optimum use of the archive function, the value of ARCHPCT should be less than the value of SLOGCUSH.
CHARNAME=name	After installation: INTERNATIONAL   After migration: ENGLISH	Character Set Name This 1- to 18-character field specifies the name of the character set that the database manager uses to define the system language. The name you specify must correspond to the name of a character set that has been defined in the NAME column of the SYSTEM.SYSCHARSETS table and the CHARNAME column of the SYSTEM.SYSCCSIDS table. The value of the CHARNAME parameter specified in the SQLSTART EXEC or startup jcl determines the values of the CHARNAME, CCSIDSBCS, CCSIDMIXED and CCSIDGRAPHIC rows in the SYSTEM.SYSOPTIONS table. It also updates the CCSID and SUBTYPE attributes for the character columns of the system catalog tables. If CHARNAME is not specified, the CHARNAME value is determined from the CCSID value of the CNAME column in the SYSTEM.SYSCOLUMNS table. For information on selecting a CHARNAME and the related performance considerations, see the DB2 Server for VSE System Administration, or DB2 Server for VM System Administration manual.
CHKINTVL=n	10	Checkpoint Interval n is a decimal value that defines when the database manager is to automatically take a checkpoint. A checkpoint is taken after every n log pages have been written. n can be any number from 1 to 99,999,999.
DISPBIAS=n	7	Dispatcher Bias n is a decimal value from 1 to 10. The DISPBIAS parameter controls how the DB2 Server for VSE & VM dispatcher operates. When the DISPBIAS parameter is set closer to 10, the dispatcher operates more like a priority dispatcher. When the DISPBIAS parameter is set closer to 1, the dispatcher operates more like a round robin dispatcher. Refer to the DB2 Server for VSE System Administration, or DB2 Server for VM System Administration manual for more information on the DISPBIAS parameter.
DSPSTATS=nn	00	This 2 character field allows values 0, 1 and 2 for option 1 and values 0 and 1 for option 2. If the first option is 1, checkpoint performance data is displayed on the console in the form of messages every time a checkpoint occurs. If the first option is 2, checkpoint performance detailed data is displayed on the console in the form of messages every time a checkpoint occurs. If the second option is 1, the COUNTER * command will be internally invoked when the database manager is shutdown. This displays the counter value for the database manager at the last possible moment. If VMDSS is activated, the COUNTER POOL * command is also issued.
DUALLOG=N|Y	N	Dual Logging This 1-character field indicates whether the database manager is to maintain two logs. Y indicates dual logging; N indicates single logging. This parameter is used only when STARTUP=L or STARTUP=C is specified. Note: The DB2 Server for VM EXECs always supply the DUALLOG parameter for you. You should not specify the DUALLOG parameter directly.
DUMPTYPE=P|F|N	F	Dump Type This 1-character field indicates the type of dump to be taken if the application server ends abnormally. F indicates a full dump. For VM, this is the entire virtual machine. For VSE, this is the entire partition. P indicates a partial dump, where everything is dumped except DB2 Server for VSE & VM code. (DB2 Server for VSE & VM control blocks are included in the dump.) N indicates no dump. No dump is taken if a DB2 Server for VSE & VM limit error or a hardware error occurs or if the termination is because of a user specification error. ATTENTION: IBM recommends that you always use DUMPTYPE=F, as most problems cannot be resolved with a partial dump. This will help eliminate the need for recreating problems just to get a full dump. Note: In single user mode, DUMPTYPE=P includes the application code in the dump.
EXTEND=Y|N	N	Filtered Log Recovery This 1-character field indicates to the database manager whether it should read EXTEND input file commands. Y means that the database manager should read EXTEND input file commands, and N, the default, means it should not. You can specify Y only when STARTUP=W, R, U, or F (F is valid for DB2 Server for VSE only). (Otherwise, you receive an error message.) Specify the EXTEND input file commands in either a CMS file that has fixed-length, 80-byte records, or in SYSIPT. Before starting the application server enter a CMS FILEDEF command with the ddname ARIEXTND that identifies the CMS file. The EXTEND input file commands are described in the DB2 Server for VSE & VM Diagnosis Guide and Reference manual. If you are starting the application server in single user mode, the single user mode job must not use SYSIPT.
LOGMODE= A|L|N|Y	Y	Logging Mode This 1-character field indicates how the database manager is to maintain the logs: A The database manager is to maintain the logs and automatically archive the database when the level specified by ARCHPCT is reached. L The database manager is to maintain the logs and automatically archive the log when the level specified by ARCHPCT is reached. N The database manager is not to maintain the logs for recovery. A log is still needed, however, for internal application server operations. A log is always needed, whether for recovery of user data or not. The physical device used for the log must always be allocated, even when LOGMODE=N is specified. You cannot specify LOGMODE=N when SYSMODE=M. Y The database manager is to maintain the logs. It is not always possible to switch log modes. Refer to the DB2 Server for VM System Administration, or DB2 Server for VSE System Administration manual for information about switching log modes. For VSE: Note that if A or L is specified, DB2 Server for VSE job control must include a TLBL statement with the file name ARIARCH for the database archive tape. If you specify LOGMODE=L, the job control must also include a TLBL statement with the file name ARILARC for the log archive tape. The database manager will dynamically assign the tape units unless you specified static assign in your startup JCL. See Figure 22 for sample JCL. When dynamic assign is chosen, your JCL must not contain an ASSGN statement. For VM: The SQLSTART EXEC issues a CMS FILEDEF command with the ddname ARIARCH for the database archive file (which can be directed only to tape). It also issues a CMS FILEDEF command with the ddname ARILARC for the log archive file (which can be directed to tape or disk). Users can enter CMS FILEDEF and LABELDEF commands for the archive file before starting the database manager. (User FILEDEFs override the FILEDEFs that SQLSTART issues.) The ddnames must be ARIARCH for database archive files and ARILARC for log archive files.
LTIMEOUT=n	0	Lock Timeout Number of seconds before a lock wait will timeout. This initialization parameter specifies a general lock wait timeout period for any SQL application, and especially as the way to avoid global deadlocks for DUOW applications. The range of the LTIMEOUT value is 0 to 99999 seconds. The default is 0, which means no timeout.
NCSCANS=n	30	Number of Concurrent Scans n is a decimal value that determines the maximum number of concurrent scans that a given user might have outstanding. A scan maintains positioning information within the database. That is, to hold information related to a DB2 Server for VSE & VM cursor. The information is kept in a scan table. The maximum size of this scan table is 32 kilobytes. The maximum number of DB2 Server for VSE & VM cursors per active agent is 255. This value might be less depending on the amount of positioning information required for a particular cursor. The average scan for a cursor is 50 bytes. n can be any number from 1 to 655. For more information, see the DB2 Server for VSE System Administration, or DB2 Server for VM System Administration manual.
NCUSERS=n	5	Number of Concurrent Users n is a decimal value that defines the maximum number of concurrent users that the database manager can support in multiple user mode. The actual number of logged-on users, however, might exceed this number. One of the uses of this value is to generate DB2 Server for VSE & VM task control blocks called agent structures (or agents). Normally, one user is associated with one agent structure.
NDIRBUF=n	NPAGBUF	Number of Directory Buffers n is a decimal value that defines how many directory buffers are to be reserved in virtual storage. These buffers are shared by all users. Each buffer requires 512 bytes. n can be any number from 10 to 400000.
NLRBS=n	Calculated	Number of Lock Request Blocks for the Application Server n is a decimal value that defines the maximum number of lock request blocks available in multiple user mode. This value limits the total number of locks that can be requested by all concurrent users. When the application server approaches this value (comes to within 2*NCUSERS of the value), the lock escalation process occurs. The default value is NCUSERS*2 + (NCUSERS*NLRBU)/2 + 10. The minimum value is the greater of 50 or NCUSERS*2. The maximum value is 583 333.
NLRBU=n	1000	Number of Lock Request Blocks per User n is a decimal value that defines the maximum number of lock request blocks available to any one user in multiple user mode. When the application server reaches this value for any application, the lock escalation process occurs. (See the LOCKLMT and ESCALATE counters under the COUNTER command on page *** for more details about lock escalation.) In general, you can assume that for every lock that an application holds, two lock request blocks are required. The minimum value is 10, and the maximum is 583,333.
NPACKAGE=n	10	Maximum Number of Active Packages in a LUW n is a decimal value that determines the maximum number of active packages in an LUW. The value of n must be in the range from 1 to m where (m x NCUSERS) must be less than 32767. For more information see the DB2 Server for VSE System Administration, or DB2 Server for VM System Administration manual.
NPACKPCT=n	30	Packages in Cache Threshold n is an integer value indicating the number of packages which will remain loaded in cache as a percentage of the total cache. n can be in the range of 0 to 100 percent. Size of package cache= NPACKAGE x NCUSERS   Threshold = size of package cache x NPACKPCT / 100 When the number of loaded packages exceeds the threshold, packages will be discarded at the end of the LUW until the number of loaded packages drops below the threshold level. The value of the threshold is truncated to an integer. If the threshold is 0, one package will be kept in cache. For more information see the DB2 Server for VSE System Administration, or DB2 Server for VM System Administration manual.
NPAGBUF=n	Calculated	Number of Data Page Buffers n is a decimal value that defines how many data page buffers are to be reserved in virtual storage. These buffers are shared by all users. Each buffer requires 4 096 bytes. The default value for n is (10 + (4 x NCUSERS)). n can be any number from 10 to 400,000.
PARMID=name	None	Name of Parameter File A 1- to 8-character name that defines a DB2 Server for VSE source member or a DB2 Server for VM CMS file that contains initialization parameters that are to override the default values. (The VM file type must be SQLPARM.)
PROCMXAB=nnn	0	Number of Stored Procedures nnn is a decimal value specifying the number of times a stored procedure is allowed to terminate abnormally, after which a STOP PROC ACTION REJECT is performed against the procedure and all subsequent SQL CALL statements are rejected. Note that a timeout that occurs while waiting for a stored procedure server to be assigned for an SQL CALL statement is not included in this count. The default, 0, means that the first abend of a stored procedure causes SQL CALLs to that procedure to be rejected. For production systems, you should accept the default.
PROGNAME=name	None	Program Name A 1- to 8-character name that defines the program to be loaded and called by the application server when the application server is initialized. The name is required for single user mode only when STARTUP=W, U, F, or R. (F is valid for DB2 Server for VSE only.) It can be the name of an application, the DBS Utility program, or a DB2 Server for VSE & VM preprocessor.
PTIMEOUT=nnnnn	180	PSERVER Timeout This parameter serves two purposes: The number of seconds before DB2 Server for VSE & VM ceases to wait for an SQL CALL to be assigned to a stored procedure server. If the PTIMEOUT interval expires, the SQL statement fails, and SQLCODE -913 is returned with SQLSTATE 40001. The number of seconds before DB2 Server for VSE & VM ceases to wait for the START PSERVER command to complete. If the PTIMEOUT interval expires, message ARI4168I is displayed and the START PSERVER command terminates. A value of 0 means that no PTIMEOUT is in effect.
SLOGCUSH=n	90	DB2 Server for VSE & VM Log Cushion n is a decimal value indicating percentage. When the log becomes n percent full, the database manager invokes the log overflow procedure. The log overflow procedure is described in the DB2 Server for VSE System Administration, and DB2 Server for VM System Administration manuals. n can be any number from 11 to 100. For optimum use of the archive function, the value for SLOGCUSH should be greater than the value of the ARCHPCT parameter.
SOSLEVEL=n	10	Short-on-Storage Level n is a decimal value indicating percentage. For LOGMODE=N, message ARI0202I is issued when n percent of the storage pool pages remain free. For every other LOGMODE, when n percent or less of the pages in the storage pool are free, the database manager takes a checkpoint in an attempt to free shadow pages. If, after this checkpoint, there are still only n percent or less free pages in the storage pool, message ARI0202I is issued once. When this message occurs, the system should be shut down as soon as possible so that more disk storage can be added to the particular storage pool (with the ADD DBEXTENT function). n can be any number from 1 to 100.
STARTUP=type	W	Type of Startup This 1-character field indicates how the application server is to be started: C Database or catalog generation (cold start). The database manager formats the entire database, including the log. E Add dbextents, delete dbextents, or both. F Restore the database from an archive tape without reformatting the database files. This can be specified only when none of the database files (BDISK, DDSK1-n) have been replaced. Type F is valid in VSE only. I Reorganize the indexes on the catalog tables. L Redefine the log data sets (COLDLOG). The LOGMODE must be set to Y. M Migrate a DB2 Server for VSE & VM database from a previous to a current version of the product. R Restore the database from an archive tape. S Add new dbspaces. U User restore. Use this parameter to start the database manager if you have just restored the database from a user archive. The storage pool will be brought up-to-date with the rest of the database if you are using the Data Restore Feature. See the DB2 Server for VSE & VM Data Restore for more information. W Normal start (warm start). Cold start (C) or COLDLOG (L) cancels the restart recovery procedure. Warm start (W), archive restore (R or F), or user restore (U) can be specified in either multiple user or single user mode. The other options can be specified only in single user mode (SYSMODE=S). Note: In VM, you should not normally specify STARTUP=C, L, E, I, M, or S. The database manager provides EXECs for each of these functions. The startup parameters are used as part of a process to perform each of the functions, but the parameters do not, in themselves, perform the entire function. For descriptions of the EXECs for values C, E, L, R, S, U and W , see the DB2 Server for VM System Administration manual; for value I see the DB2 Server for VSE & VM Database Administration manual, and for value M see the DB2 Server for VM Program Directory.
SYNCPNT=Y|N	Y	Sync point manager (SPM) support This 1-character field indicates whether or not a sync point manager (SPM) will be used to coordinate DRDA-2 DUOW two-phase commit and resynchronization activity. Y means that the server will use a sync point manager, if possible, to coordinate the two-phase commits and resynchronization activity. N means that the server will not use an SPM to perform two-phase commits. Also if N is specified, DB2 Server for VSE & VM is limited to multi-read, single-write distributed units of work and it can be the single-write site. Note: If Y is specified, but DB2 Server for VSE & VM finds that a sync point manager is not available, then the server will operate as if N was specified.
SYSMODE=M|S	M	System Mode This 1-character field indicates whether the application server is to run in single user mode (S) or multiple user mode (M).
SECALVER=Y|N	N	Security The value of this parameter is determined by the value of the SECTYPE parameter. If SECALVER=Y is specified, and the requester sent a userid but no password for authentication, the application server assumes that the user is already verified. If SECALVER=N is specified, the application server assumes that the user is not already verified and a password or PassTicket must accompany a userid for authentication. This parameter is valid only when the incoming connect request is via TCP/IP from any type of requester or when the incoming connect request is from a DB2 Server for VSE DRDA application requester via SNA.
SECTYPE=DB2|ESM	DB2	Security If SECTYPE=DB2 is specified, the SYSTEM.SYSUSERAUTH table is checked if the user has connect authority; the password column is not checked. If SECTYPE=ESM is specified, a check is performed during initialization to ensure that the external security manager is available and that it supports the RACROUTE interface. This parameter is valid only when the incoming connect request is via TCP/IP from any type of requester or when the incoming connect request is from a DB2 Server for VSE DRDA application requester via SNA.
TCPPORT=nnnnn		This identifies the TCP/IP port number as an integer in the range of 1 to 65535. If TCPPORT=0 is specified, no TCP/IP initialization will be attempted. For VSE, if TCPPORT is not specified, the DBNAME directory will determine whether TCP/IP initialization is required and what port number should be used. For VM, if TCPPORT is not specified, the ETC SERVICES file is used to determine what port number should be used. Note: For VSE, the same TCP/IP port number can be used among different application servers to initialize TCP/IP support. In this case, the last server using the duplicate port number will become the target server owning the port. All later incoming connect requests using this port number will be connected to this target server. To avoid misdirected connection requests, duplicate port numbers should not be used.

Common Tracing Parameters

During DB2 Server for VSE initialization, the application server prompts you for the tape cuu or DISK. The DISK reply causes the application server to open a DASD SAM file for tracing. If any tracing is to be done, DB2 Server for VSE job control must include a TLBL or DLBL statement with the file name ARITRAC.

During DB2 Server for VM initialization, the SQLSTART EXEC supplies this (default) CMS FILEDEF command: FILEDEF ARITRAC TAP2 SL (BLKSIZE 4096 NOCHANGE PERM

Parameter	Default	Description
TRACDBSS= nnnnnnnnnnn	Zeros	Tracing in DBSS This 11-digit parameter specifies the parts of the DBSS that are to be traced and the level. Where 0 is specified, tracing is not done. Where 1 is specified, tracing displays only module entry and exit points. Where 2 is specified, tracing is done in greater detail. The positional digits correspond to the following DBSS functions and subcomponents: ENTRY, EXIT, LOG, LOCK, LUW, DC, DM, STOR, SORT, INDEX, and STAT. (A description of these is in Starting a Trace.)
TRACDRRM=nnnn	Zeros	Tracing of the DRRM component This four-digit parameter specifies the parts of the DRRM that are to be traced and the level. Where 0 is specified, tracing is not done. Where 1 is specified, tracing displays only module entry and exit points. Where 2 is specified, tracing is done in greater detail. The positional digits correspond to the following DRRM functions and subcomponents: the first is the DDM Parser, the second is the DDM GENERATOR, the third is the DDM Data Dictionary, and the fourth is the RDIIN Manager. (A description of these is in Starting a Trace.) Note: You will only receive trace output for the work unit manager if you specified AUTO for the PROTOCOL parameter.
TRACDSC=nn	Zeros	Tracing of the DSC component This two-digit parameter specifies the parts of the DSC component to be traced and the level. Where 0 is specified, no tracing is done. Where 1 is specified, tracing is done in limited detail. Where 2 is specified, tracing is done in greater detail. The positional digits correspond to the following DSC functions and subcomponents: AGENT and COM. (A description of these is in Starting a Trace.)
TRACEBUF=n	Zero	Tracing in Memory The parameter n specifies the amount of memory in kilobytes that you want to allocate to the trace buffer. The range of the TRACEBUF integer value n is 0 to 99999. A suggested size for the trace buffer is 100 kilobytes or more. It is recommended that you increase either the Virtual Machine memory or the size of the partition by the size of the trace buffer before you start a trace in memory. The trace buffer will only be created if you specify TRACEBUF with at least one of the startup initialization parameters TRACCONV, TRACRDS, TRACDBSS, TRACDSC, TRACDRRM, TRACSTG, or TRACWUM. Trace records are stored in wrap-around mode in a fixed size buffer. A trace buffer will not be created if the TRACEBUF default or n=0 is selected. If there are records in the buffer, they are written to the trace output file by the TRACE OFF command or by DB2 Server for VSE & VM shut down processing. For details see SQLEND and TRACE OFF operator commands on pages *** and *** respectively. Note: If there is insufficient storage available for the trace buffer, error message ARI0155E will be displayed on the operator console and the system will not be started.
TRACRDS=nnnnnnn	Zeros	Tracing in RDS This seven-digit parameter specifies the parts of the RDS to be traced and the level. Where 0 is specified, tracing is not done. Where 1 is specified, tracing displays only module entry and exit points. Where 2 is specified, tracing is done in greater detail. The positional digits correspond to the following RDS functions and subcomponents: EXEC, PA, OPT, AG, INT, AU, and SG. (A description of these is in Starting a Trace.)
TRACSTG=n	Zero	Tracing in the System and Working storage This parameter can be specified on the application server side only. It can be invoked during startup when the database is first initialized and with the operator TRACE command. The TRACSTG parameter has no subcomponents. Values of n are 0 which specifies no trace and 1 which specifies a level 1 trace.
TRACWUM=n	Zero	Tracing in the Work Unit Manager This parameter specifies the level of tracing for the work unit manager. Where 0 is specified, tracing is not done. Where 1 is specified, tracing is done for module entries and exits. Where 2 is specified, tracing is done in greater detail. Note: You will only receive trace output for the work unit manager if you specified AUTO for the PROTOCOL parameter.
TRACCONV=n	Zero	Tracing of the CONV component This parameter n specifies the level of tracing for the CONV component. Where 0 is specified, tracing is not done. Where 1 is specified, tracing is done in limited detail. Where 2 is specified, tracing is done in greater detail.