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MDBX_COPY(1)		     General Commands Manual		    MDBX_COPY(1)

NAME
     mdbx_copy - MDBX environment copy tool

SYNOPSIS
     mdbx_copy [-V] [-q] [-c] [-d] [-p] [-n] src_path [dest_path]

DESCRIPTION
     The  mdbx_copy  utility  copies an MDBX environment. The environment can be
     copied regardless of whether it is currently in use.  No lockfile	is  cre-
     ated, since it gets recreated at need.

     If  dest_path  is	specified  it must be the path of an empty directory for
     storing the backup. Otherwise, the backup will be written to stdout.

OPTIONS
     -V     Write the library version number to the standard output, and exit.

     -q     Be quiet.

     -c     Compact while copying. Only current data pages will be copied; freed
	    or unused pages will be omitted from the copy. This option will slow
	    down the backup process as it is more CPU-intensive.   Currently  it
	    fails if the environment has suffered a page leak.

     -d     Alters  geometry  to enforce the copy to be a dynamic size DB, which
	    could be growth and shrink by reasonable steps on the fly.

     -p     Use read transaction parking/ousting during  copying  MVCC-snapshot.
	    This  allows  the  writing	transaction to oust the read transaction
	    used to copy the database if copying takes so long that it will  in-
	    terfere  with  the	recycling  old MVCC snapshots and may lead to an
	    overflow of the database.  However, if the	reading  transaction  is
	    ousted  the  copy will be aborted until successful completion. Thus,
	    this option allows copy the database without interfering with  write
	    transactions and a threat of database overflow, but at the cost that
	    copying will be aborted to prevent such conditions.

     -u     Warms up the DB before copying via notifying OS kernel of subsequent
	    access to the database pages.

     -U     Warms  up  the  DB before copying, notifying the OS kernel of subse-
	    quent access to the database pages, then forcibly loads ones by  se-
	    quential access and tries to lock database pages in memory.

     -n     Open  MDBX	environment(s) which do not use subdirectories.  This is
	    legacy option. For now MDBX handles this automatically.

DIAGNOSTICS
     Exit status is zero if no errors occur.  Errors result in a  non-zero  exit
     status and a diagnostic message being written to standard error.

CAVEATS
     This  utility  can  trigger significant file size growth if run in parallel
     with write transactions, because pages which they free during copying  can-
     not be reused until the copy is done.

SEE ALSO
     mdbx_dump(1), mdbx_chk(1), mdbx_stat(1), mdbx_load(1) mdbx_drop(1)

AUTHOR
     Howard  Chu  of  Symas  Corporation  <http://www.symas.com>,  Leonid Yuriev
     <https://gitflic.ru/user/erthink>

MDBX 0.13			   2024-08-29			    MDBX_COPY(1)

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