Parameter Reference
Complete guide to configuration and runtime parameters
Setting Parameters
Use param <name> <value>; to set parameters. Use show; to view current values.
This documentation applies to Linux and source versions MySQL 5.7.44, 8.0.28 and 8.0.46. Before recovery, copy the data directory, Binlog, Redo/Undo and schema evidence, and work on a separate copy. Confirm other versions and special layouts separately.
Configuration File (pdu.ini)
MYSQL_DATADIRRequiredPath to an offline MySQL data-directory copy used for metadata initialization and table-file identification.
MYSQL_DATADIR=/recovery-input/mysql/dataDDLMatching CREATE TABLE file for one table. Metadata definitions may be used when initialization has identified the table.
DDL=DATAFILEOffline IBD copy to parse.
DATAFILE=BINLOGClosed Binlog file, numbered-log directory or .index list.
BINLOG=/recovery-input/mysql/binlogRESMODESelect the tx, time, dead, undo, redo or history recovery path. Modes use different sources and transaction evidence.
RESMODE=txRESTYPESelect delete, update or all to determine scan and restore operation types.
RESTYPE=deleteRESTORETARGETexisting targets an existing database; rebuild uses an offline snapshot for a reconstruction path. Matching schema and dependency evidence are required.
RESTORETARGET=existingstartwalFirst Binlog name used to restrict a continuous log range.
startwal=endwalLast Binlog name.
endwal=STARTPOSStarting event boundary in the first log; arbitrary byte offsets are not accepted.
STARTPOS=ENDPOSEnding event boundary in the last log; use the actual parsed position.
ENDPOS=starttimeInclusive UTC commit-time start, used with resmode=time.
starttime=endtimeExclusive UTC commit-time end.
endtime=INDEX_IDClustered-index ID confirmed from matching metadata.
INDEX_ID=redoOffline Redo log directory.
redo=redobaselsnVerified base checkpoint; do not guess an arbitrary LSN.
redobaselsn=redoendlsnVerified complete-MTR ending position; an empty value replays all retained logs.
redoendlsn=Runtime Path Parameters
datadirpathDefault: unsetPath to an offline MySQL data-directory copy used for metadata initialization and table-file identification.
param datadir /recovery-input/mysql/data;ddlpathDefault: unsetMatching CREATE TABLE file for one table. Metadata definitions may be used when initialization has identified the table.
param ddl /recovery-input/orders.sql;datafilepathDefault: unsetOffline IBD copy to parse.
param datafile /recovery-input/orders.ibd;binlogpathDefault: unsetClosed Binlog file, numbered-log directory or .index list.
param binlog /recovery-input/mysql/binlog;Recovery Mode Parameters
resmodeenumDefault: txSelect the tx, time, dead, undo, redo or history recovery path. Modes use different sources and transaction evidence.
param resmode tx;restypeenumDefault: deleteSelect delete, update or all to determine scan and restore operation types.
param restype update;restoretargetenumDefault: existingexisting targets an existing database; rebuild uses an offline snapshot for a reconstruction path. Matching schema and dependency evidence are required.
param restoretarget existing;historyddlpathDefault: unsetHistorical CREATE definitions from before the log range; this does not enable automatic rollback across arbitrary DDL.
param historyddl /recovery-input/history.sql;Log Range Parameters
startwalstringDefault: unsetFirst Binlog name used to restrict a continuous log range.
param startwal binlog.000010;endwalstringDefault: unsetLast Binlog name.
param endwal binlog.000012;startposintegerDefault: unsetStarting event boundary in the first log; arbitrary byte offsets are not accepted.
param startpos 4;endposintegerDefault: unsetEnding event boundary in the last log; use the actual parsed position.
param endpos <event_boundary>;starttimeUTC datetimeDefault: unsetInclusive UTC commit-time start, used with resmode=time.
param starttime "2026-09-08 00:00:00";endtimeUTC datetimeDefault: unsetExclusive UTC commit-time end.
param endtime "2026-09-09 00:00:00";gtidGTID setDefault: unsetFilter retained GTID transactions using actual UUID:NUMBER ranges.
param gtid <UUID>:1-20;Data File Parameters
indexidintegerDefault: unsetClustered-index ID confirmed from matching metadata.
param indexid <clustered_index_id>;sdifilepathDefault: unsetSDI source file containing table definitions for manual partition parsing.
param sdifile /recovery-input/first-partition.ibd;keyringpathDefault: unsetMatching encryption-key file whose identity must correspond to the encrypted tablespace.
param keyring /recovery-input/keyring;spacepathspath listDefault: unsetOne absolute path per line for external tablespace or Undo files/directories.
param spacepaths /recovery-input/spacepaths.txt;systemfilespath listDefault: unsetAbsolute paths to offline system-tablespace files in their original order.
param systemfiles /recovery-input/systemfiles.txt;metadatadirpathDefault: unsetFrozen 5.7 metadata copy containing ibdata1 and FRM.
param metadatadir /recovery-input/mysql57-metadata;Redo Recovery Parameters
redopathDefault: unsetOffline Redo log directory.
param redo /recovery-input/redo;redobaselsnLSNDefault: unsetVerified base checkpoint; do not guess an arbitrary LSN.
param redobaselsn <verified_checkpoint>;redoendlsnLSNDefault: unsetVerified complete-MTR ending position; an empty value replays all retained logs.
param redoendlsn <complete_mtr_end>;