18.17.2 Determining the minimum number of system log files to be added

The following formula is used to obtain the minimum number of system log files to be added:

Formula
Minimum-number-of-system-log-files-to-be-added = L - {N - (M + Z*)}
When the result of this formula is less than 1, there is no need to add system log files.
L: Number of system log files to be used as the input information during restart
This is the value derived as described in 18.17.1(2) Determine the number of system log files to be used as input information during restart.
M: Number of system log files in overwrite disabled status
See (1) below for the procedure for determining the number of system log files in overwrite disabled status.
N: Total number of system log files in the server
Count the number of spare files also. For details about spare files, see 18.17.3(3) Use a spare file.
Z: Number of system log files in overwrite enabled and unload wait status
* Add this value if operation without unloading of the system log is being used.
Organization of this subsection
(1) Determining the number of system log files in overwrite disabled status
(2) Determining the number of system log files in overwrite disabled status (number of valid generations = 2)

(1) Determining the number of system log files in overwrite disabled status

The pdlogls command cannot be used during offline operation to determine whether or not a system log file is in overwrite disabled status. The number of system log files in overwrite disabled status can be determined from messages that are output during restart processing:

Contents of the syslogfile

KFPS01800-I PRDT untF Now starting HiRDB unit untF (19924)
KFPS01262-I PRDT untF Log block reading started. type:sys(bes1),
read start point:logfg04,4,d (19993)
KFPS01182-I PRDT untF Generation file groups changed for further
reading of log blocks. type:sys(bes1), from:logfg04,4, to:logfg05,5,
read direction:f (19993)
KFPS01182-I PRDT untF Generation file groups changed for further
reading of log blocks. type:sys(bes1), from:logfg05,5, to:logfg06,6,
read direction:f (19993)
KFPS01182-I PRDT untF Generation file groups changed for further
reading of log blocks. type:sys(bes1), from:logfg06,6, to:logfg07,7,
read direction:f (19993)
KFPS01263-I PRDT untF Log block reading completed. type:sys(bes1),
read end point:logfg07,7,1e (19993)
KFPS01220-E PRDT untF Request to swap sys(bes1) log file unable to be
executed because there is no standby log file group available. (19993)
KFPO00105-E PRDT untF Server _log1s(process ID=19993) killed by
code=Psjnf07(19993)
KFPS01821-E PRDT untF Unable to continue HiRDB unit processing because
serious error occurred; stops HiRDB unit untF (19979)

Explanation
KFPS01262-I, KFPS01182-I, and KFPS01263-I indicate that system log files logfg04, logfg05, logfg06, and logfg07 are used during the restart. These are the overwrite disabled files, so the number of system log files in overwrite disabled status is 4:
[Figure]
Reference note

(2) Determining the number of system log files in overwrite disabled status (number of valid generations = 2)

In (1) above, the system log files in overwrite disabled status that were in existence after the most recent synchronization point dump generation was validated were identified. If the number of synchronization point dump guaranteed valid generations is 2, the files in overwrite disabled status that were in existence up to the point where the previous synchronization point dump generation was validated must also be identified. There are two ways to identify these files:

(a) Using the synchronization point dump validation completion message (KFPS02183-I)

The files in overwrite disabled status can be identified using the KFPS02183-I message and the pdlogls command:

Contents of the syslogfile

KFPS05210-I PRDT untF HiRDB system initialization process complete(13778)
KFPS01221-I PRDT untF logfg03 assigned as current file group of sys(bes1)
log file. generation number=3, first block number=a (13830)
KFPS02183-I PRDT untF Syncpoint dump for bes1 has been acquired to file
group spdfg03. log file information:logfg03, 3, a. start time=15:53:11,
end time=15:53:11 (13830)    ...1

KFPS02183-I PRDT untF Syncpoint dump for bes1 has been acquired to file
group spdfg04.  log file information:logfg04, 4, d. start time=15:54:40,
end time=15:54:41 (13830)    ...2

KFPS01222-I PRDT untF logfg04 released from sys(bes1) log file. generation
number=4, first block number=d, last block number=e (13830)
KFPS01224-I PRDT untF sys(bes1) log does not have standby file group
available for next swapping. (13830)
KFPS01220-E PRDT untF Request to swap sys(bes1) log file unable to be
executed because there is no standby log file group available.(13830)
KFPO00105-E PRDT untF Server _log1s(process ID=13830) killed by code=
Psjnf07(13830)
KFPS01821-E PRDT untF Unable to continue HiRDB unit processing because
serious error occurred; stops HiRDB unit untF (13776)
KFPS01229-I PRDT untF Next bes1 log file restart point, generation
number=4, block number=d. restart end point, generationnumber=7,
block number=1c. last acquired syncpoint dump 1998/11/15 15:54:41 (13776)

pdlogls command execution results:

pdlogls -d sys -s bes1

HOSTNAME : dcm3500(163541)
***** Off-line Information *****
Group    Type Server   Gen No.  Status    Run ID       Block No.
logfg01  sys  bes1     1        cna---u   364a4ac2     1        6
logfg02  sys  bes1     2        cna---u   364a4ac2     7        9
logfg03  sys  bes1     3       cna---u   364a4ac2     a        c
logfg04  sys  bes1     4       cna---u   364a4ac2     d        e
logfg05  sys  bes1     5        cna---u   364a4ac2     f        10
logfg06  sys  bes1     6        cna---u   364a4ac2     11       11
logfg07  sys  bes1     7        cn---cu   364a4ac2     12       0
logfg08  sys  bes1     0        cn-----   00000000​     0        0

Explanation
  1. This is the message regarding validation of the previous synchronization point dump generation. The indicated system log file is logfg03 (generation number 3).
  2. This is the message regarding the most recent synchronization point dump generation. The indicated system log file is logfg04 (generation number 4).
It is clear from the first message that logfg03 is also in overwrite disabled status. Therefore, logfg03 through logfg07 are all in overwrite disabled status:
[Figure]
(b) Using the synchronization point dump validation skip message (KFPS02179-I)

The files in overwrite disabled status can be identified from the KFPS02179-I message:

Contents of the syslogfile

KFPS01221-I PRDT untF logfg02 assigned as current file group of sys(bes1)
log file. generation number=b, first block number=66 (5075)
KFPS01222-I PRDT untF logfg02 released from sys(bes1) log file. generation
number=b, first block number=66, last block number=66 (5075)
KFPS01221-I PRDT untF logfg03 assigned as current file group of sys(bes1)
log file. generation number=c, first block number=67 (5075)   ...3

KFPS01222-I PRDT untF logfg03 released from sys(bes1) log file.generation
number=c, first block number=67, last block number=68 (5075)
KFPS01221-I PRDT untF logfg04 assigned as current file group of sys(bes1)
log file.generation number=d, first block number=69 (5075)   ...1

KFPS02179-I PRDT untF Syncpoint dump acquisition opportunities for bes1
service were skipped.number of skip=1,log generation number=d factor
code=A01-02 (5054)   ...2

KFPS02179-I PRDT untF Syncpoint dump acquisition opportunities for bes1
service were skipped.number of skip=1,log generation number=d factor
code=A01-02 (5054)
KFPS01222-I PRDT untF logfg04 released from sys(bes1) log file.generation
number=d, first block number=69, last block number=73 (5075)

Explanation
  1. Look for the KFPS01221-I message indicating that logfg04, which is the system log input start point during the restart, was allocated as the current file.
  2. Look for the KFPS02179-I message indicating that the validation skips count was set to 1 while logfg04 was being used as the current file.
  3. If the KFPS02179-I message was output while logfg04's predecessor (logfg03) was used as the current system log file, look for the KFPS02179-I message indicating the validation skips count = 1, and identify the system log file that was being used as the current file when that message was output. Then determine the additional number of overwrite-disabled system log files from the following table:
    ConditionOutput of KFPS02179-I message while the previous system log file generation was allocated as the current file
    OutputNot output
    Validation skips count [Figure] 1Validation skips count = 1
    Output of KFPS02179-I message while the input start system log file was allocated as the current file at the restartOutput(Number of files existing up to the point where the message indicating skips count = 1 was output) + 122
    Not output1
Note
The number of files in overwrite disabled status determined in (1) plus the number of overwrite-disabled files determined above cannot exceed the total number of system log files in the corresponding HiRDB server. If the total number of system log files is exceeded, the total number of system log files in the corresponding HiRDB server must be used as the total number of overwrite-disabled system log files.

In this example, the KFPS02179-I message was output while logfg04, which is at the system log input start point during restart, was allocated as the current file. The KFPS02179-I message was not output while its predecessor, logfg03, was allocated as the current file. Therefore, logfg03 and logfg02 are identified as the system log files in overwrite disabled status, and a value of 2 is added to the result of (1).

[Figure]