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LOG | Changes the volumes for the original RLOG file. |
LOG-2 | |
Changes the volumes for the duplicate RLOG file. | |
:catid: | BS2000 catalog ID (see section “Using pubsets in UDS/SQL”). |
PUBLIC | |
The RLOG file or duplicate RLOG file is created on public disk (PUBLIC VOLUME) under the default catalog ID of the configuration user ID. | |
priv-vsn | |
The RLOG file or duplicate RLOG file is created on private disk. Up to three volume serial numbers can be specified, no two of which may be the same. A volume serial number may comprise up to six alphanumeric characters. | |
device | Device type of the private disk. The device type may comprise up to eight alphanumeric characters. |
vsn | The RLOG file or the duplicate of the RLOG file is created on disks which are allocated to an SF pubset or to a volume set of an SM pubset. Up to three VSNs can be specified, no two of which may be the same. The VSN can be specified in PUB notation (PUBpxx) or in dot notation (pp[pp].[xy]z). Please also take into account “Additional conditions for VSN specifications”. |
You may specify up to three volumes.
A DAL command may be up to 64 characters in length. With long volume specifications the abbreviations MOD and VAL can be used. LOG-2 must be fully written out, to avoid ambiguity.
The DAL commands MODIFY LOG and MODIFY LOG-2 enable you to change the volume allocation for an original or duplicate RLOG file to be newly created. The changes are securely recorded in the session log file (SLF) for use in a session restart.
Whether or not a duplicate RLOG file is to be maintained is specified on starting the DBH. This determination cannot be changed later with the DAL command MODIFY. The DAL command MODIFY can be used to change the volumes for the RLOG files.
When a duplicate RLOG file is maintained the original and duplicate files must be kept on different volumes. The volume specified in the MODIFY command is compared to the existing volume; if the volumes are the same, the command is rejected.
The amount of storage for the RLOG files can be changed with the DAL command MODIFY LOG-SIZE.
Reserve volumes for single and duplicate RLOG files can be specified with the DAL command MODIFY RESERVE.
The new setting must correspond to a pubset which is located within the pubset space of the current UDS/SQL pubset declaration. When a MOD LOG statement is issued between an accepted DAL NEW PUBSETS and the subsequent PERFORM, the new setting must correspond to a pubset which is also located within the pubset space of the new UDS/SQL pubset declaration. If these conditions are not fulfilled, the MODIFY RESERVE command is rejected.
Additional conditions for VSN specifications
The following special rules apply for VSN specifications when the RLOG files are created on disks which are allocated to an SF pubset or to a volume set of an SM pubset:
VSN specifications are permissible only when authorization exists for physical allocation of public storage space on the pubset concerned.
In both PUB notation (PUBpxx) and dot notation (pp[pp].[xy]z) it is permissible to omit the sequence number of the disk (xx or [xy]z), in which case only a single VSN specification is possible.
This enables the RLOG file to be created on any volumes of an SM pubset’s volume set.
Examples:
(PUBX01,PUBX02)
RLOG file on volumes PUBX01 and PUBX02 in the singlecharacter SF pubset X or volume set X of an SM pubset
(PUBX)
RLOG file on any volume in the single-character SF pubset X or volume set X of an SM pubset
(ABC.01,ABC.02)
RLOG file on volumes ABC.01 and ABC.02 in the threecharacter SF pubset ABC or volume set ABC of an SM pubset
(ABC.)
RLOG file on any volume in the three-character SF pubset ABC or volume set ABC of an SM pubset
If multiple volumes are specified for an RLOG file, these must belong to the same volume set, i.e. the VSNs must contain the same catalog ID. A file cannot extend over multiple volumes sets.
Twin logging files must be created on different volume sets because when a volume fails the entire volume set is generally no longer available.
In addition, one of the twin logging files may also not be created on a volume set of an SM pubset if the other is created in this SM pubset on account of a :catid: or PUBLIC specification.
The following must be borne in mind when the control volume set of an SM pubset is specified for a copy of RLOG or two volume sets of an SM pubset are specified for the RLOG original and duplicate:
If the control volume set of an SM pubset fails, the entire SM pubset is temporarily no longer accessible. (Reconstruction of the SM pubset is possible.)