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Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/pg_combinebackup.sgml | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/doc/src/sgml/ref/pg_combinebackup.sgml b/doc/src/sgml/ref/pg_combinebackup.sgml index 6f90dba281f..658e9a759c8 100644 --- a/doc/src/sgml/ref/pg_combinebackup.sgml +++ b/doc/src/sgml/ref/pg_combinebackup.sgml @@ -186,6 +186,51 @@ PostgreSQL documentation </varlistentry> <varlistentry> + <term><option>--clone</option></term> + <listitem> + <para> + Use efficient file cloning (also known as <quote>reflinks</quote> on + some systems) instead of copying files to the new data directory, + which can result in near-instantaneous copying of the data files. + </para> + + <para> + If a backup manifest is not available or does not contain checksum of + the right type, file cloning will be used to copy the file, but the + file will be also read block-by-block for the checksum calculation. + </para> + + <para> + File cloning is only supported on some operating systems and file + systems. If it is selected but not supported, the + <application>pg_combinebackup</application> run will error. At present, + it is supported on Linux (kernel 4.5 or later) with Btrfs and XFS (on + file systems created with reflink support), and on macOS with APFS. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><option>--copy-file-range</option></term> + <listitem> + <para> + Use the <function>copy_file_range</function> system call for efficient + copying. On some file systems this gives results similar to + <option>--clone</option>, sharing physical disk blocks, while on others + it may still copy blocks, but do so via an optimized path. At present, + it is supported on Linux and FreeBSD. + </para> + + <para> + If a backup manifest is not available or does not contain checksum of + the right type, <function>copy_file_range</function> will be used to + copy the file, but the file will be also read block-by-block for the + checksum calculation. + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><option>-V</option></term> <term><option>--version</option></term> <listitem> |