=head1 OmniPITR - omnipitr-backup-master =head2 USAGE /some/path/omnipitr/bin/omnipitr-backup-master [options] Options: =over =item --data-dir (-D) Where PostgreSQL datadir is located (path) =item --database (-d) Which database to connect to to issue required SQL queries. Defaults to template1. =item --host (-h) Which host to connect to when connecting to database to backup. Shouldn't really be changed in 99% of cases. Defaults to empty string - i.e. use UNIX sockets. =item --port (-p) Which port to connect to when connecting to database. Defaults to 5432. =item --username (-U) What username to use when connecting to database. Defaults to postgres. =item --xlogs (-x) Directory that will be created. Then - will be used as source of xlogs to archive. Afterwards - it will be removed. This directory should be the same as --dst-backup for omnipitr-archive, and it shouldn't exist before running I. =item --dst-local (-dl) Where to copy the hot backup files on current server (you can provide many of these). You can also specify compression per-destination. Check L section of the doc. =item --dst-remote (-dr) Where to copy the hot backup files on remote server. Supported ways to transport files are rsync and rsync over ssh. Please see L for more information (you can provide many of these) You can also specify compression per-destination. Check L section of the doc. =item --dst-direct (-dd) Specifies remote location to be used to store backup. Please check L part for more details. =item --dst-pipe (-dp) Specifies path to program that should receive whole backup on stdin. The program will be called multiple times (for each file separately). Name of the file will be given as first, and only, argument to the program. If the file is to be compressed (using standard compression=/path syntax) - given file name will contain compression extension. =item --temp-dir (-t) Where to create temporary files (defaults to /tmp or I<$TMPDIR> environment variable location) =item --log (-l) Name of logfile (actually template, as it supports %% L markers. Unfortunately due to the %x usage by PostgreSQL, We cannot use %% macros directly. Instead - any occurence of ^ character in log dir will be first changed to %, and later on passed to strftime. Please note that on some systems (Solaris for example) default shell treats ^ as special character, which requires you to quote the log filename (if it contains ^ character). So you'd better write it as: --log '/var/log/omnipitr-^Y-^m-^d.log' =item --filename-template (-f) Template for naming output files. Check L section for details. =item --pid-file Name of file to use for pidfile. If it is specified, than only one copy of I (with this pidfile) can run at the same time. Trying to run second copy of I will result in an error. =item --parallel-jobs (-PJ) Number of parallel jobs that I can spawn to deliver archives to remote destinations. =item --verbose (-v) Log verbosely what is happening. =item --not-nice (-nn) Do not use nice for compressions. =item --digest (-dg) Digest method to use (eg MD5 or SHA-1) for checksumming. Can be a comma seperated list to use multiple digest algorithms. For details please check L below. =item --skip-xlogs (-sx) Make I skip creation of xlog tarball - only data tarball will be created. This is useful if you have set proper walarchive. =item --gzip-path (-gp) Full path to gzip program - in case you can't set proper PATH environment variable. =item --bzip2-path (-bp) Full path to bzip2 program - in case you can't set proper PATH environment variable. =item --lzma-path (-lp) Full path to lzma program - in case you can't set proper PATH environment variable. =item --lz4-path (-ll) Full path to lz4 program - in case you can't set proper PATH environment variable. =item --xz-path (-xz) Full path to xz program - in case you can't set proper PATH environment variable. =item --nice-path (-np) Full path to nice program - in case you can't set proper PATH environment variable. =item --tar-path (-tp) Full path to tar program - in case you can't set proper PATH environment variable. =item --tee-path (-ep) Full path to tee program - in case you can't set proper PATH environment variable. =item --rsync-path (-rp) Full path to rsync program - in case you can't set proper PATH environment variable. =item --psql-path (-pp) Full path to psql program - in case you can't set proper PATH environment variable. =item --ssh-path (-ssh) Full path to ssh program - in case you can't set proper PATH environment variable. =item --shell-path (-sh) Full path to shell to be used when calling compression/archiving/checksumming. It is important becaus the shell needs to support >( ... ) constructions. One of the shells that do support it is bash, and this is the default value for --shell-path. You can substitute different shell if you're sure it supports mentioned construction. =item --remote-cat-path (-rcp) Path to cat program, to be run on remote side, when using direct destinations. Defaults to "cat" It will be used as command on remote machine, as: ssh host 'cat - > /some/path/filename-from-template' In case remote-cat-path would be given with ! as the first character, it will change the invocation on remote machine, to pass filename as argument. For example: -rcp '!/usr/local/bin/store-backup' will run: ssh host '/usr/local/bin/store-backup /some/path/filename-from-template' =item --version (-V) Prints version of I, and exists. =item --help (-?) Prints this manual, and exists. =item --config-file (--config / --cfg) Loads options from config file. Format of the file is very simple - each line is treated as argument with optional value. Examples: --verbose --host 127.0.0.1 -h=127.0.0.1 --host=127.0.0.1 It is important that you don't need to quote the values - value will always be up to the end of line (trailing spaces will be removed). So if you'd want, for example, to have magic-option set to "/mnt/badly named directory", you'd need to quote it when setting from command line: /some/omnipitr/program --magic-option="/mnt/badly named directory" but not in config: --magic-option=/mnt/badly named directory Empty lines, and comment lines (starting with #) are ignored. =back =head2 DESCRIPTION Running this program should be done by cronjob, or manually by database administrator. Run this command as the same user as your postgres, or else you might have permission issues, such as omnipitr-archive not being able to write to the --dst-backup destination. As a result of running it there are 2 files, usually named HOST-data-YYYY-MM-DD.tar and HOST-xlog-YYYY-MM-DD.tar. These files can be optionally compressed and delivered to many places - both local (on the same server) or remote (via rsync). Which options should be given depends only on installation, but generally you will need at least: =over =item * --data-dir Backup will process files in this directory. =item * --log to make sure that information is logged someplace about archiving progress =item * one of --dst-local or --dst-remote to specify where to send the backup files to =back Of course you can provide many --dst-local or many --dst-remote or many mix of these. Generally omnipitr-backup-master will try to deliver WAL segment to all destinations. In case remote destination will fail, omnipitr-backup-master will retry 3 times, with 5 minute delay between tries. In case of errors when writing to local destination - it is skipped, and error is logged. Backups will be transferred to destinations in this order: =over =item 1. All B destinations, in order provided in command line =item 2. All B destinations, in order provided in command line =back =head3 Remote destination specification I delivers backup files to destination using rsync program. Both direct-rsync and rsync-over-ssh are supported (it's better to use direct rsync - it uses less resources due to lack of encryption. Destination url/location should be in a format that is usable by I program. For example you can use: =over =item * rsync://user@remote_host/module/path/ =item * host:/path/ =back To allow remote delivery you need to have rsync program. In case you're using rsync over ssh, I program has also to be available. In case your rsync/ssh programs are in custom directories simply set I<$PATH> environemnt variable before starting PostgreSQL. =head2 DIRECT-DESTINATION In some cases the overhead of creating local tarball with backup, can be too much of a burden for the system. To make the backup generation as light on resources as possible, direct destinations have been added. When using them, L doesn't create any local tarballs. Instead, output from tar (after optional compression) is sent directly to remote machine over SSH connection. Example data flow: tar cf - . | gzip -c - | ssh user@host 'cat - > /some/file' In case you'd like to use compression, but do it on remote machine, you can provide --remote-cat-path starting with !, and point it to script that does compression, and stores to proper file. For example, calling L with following options: -dd user@host:/var/backups -rcp '!/usr/local/bin/gzip-and-store' Will run (a bit simplified example): tar cf - . | ssh user@host '/usr/local/bin/gzip-and-store /var/backups/filename-from-template' And then you can write this simplistic script as /usr/local/bin/gzip-and-store: #!/usr/bin/env bash gzip -c - > "$1".gz Which will make tarball on database server (it has to be run here, since that's where the files are), then transfer the tarball over ssh to remote machine, compress it there and store in /var/backups/. Of course --dst-direct can be compressed locally, using the same syntax as with --dst-local or --dst-remote, i.e. by using "xxx=" prefix, which is described in more details in L part. =head2 COMPRESSION Every destination can have specified compression. To use it you should prefix destination path/url with compression type followed by '=' sign. Allowed compression types: =over =item * gzip Compresses with gzip program, used file extension is .gz =item * bzip2 Compresses with bzip2 program, used file extension is .bz2 =item * lzma Compresses with lzma program, used file extension is .lzma =item * lz4 Compresses with lz4 program, used file extension is .lz4 =item * xz Compresses with xz program, used file extension is .xz =back All compressions are done I> to make the operation as unobtrusive as possible. If you want to pass any extra arguments to compression program, you can either: =over =item * make a wrapper Write a program/script that will be named in the same way your actual compression program is named, but adding some parameters to call =item * use environment variables All of supported compression programs use environment variables: =over =item * gzip - GZIP =item * bzip2 - BZIP2 =item * lzma - XZ_OPT =back For details - please consult manual to your choosen compression tool. =back B =head2 CHECKSUMMING OmniPITR can (since version 0.2.0) calculate checksums of created files. To calculate the checksums, OmniPITR uses Digest Perl module (part of standard Perl distribution). Digest module supports (now) 5 different types of checksums: =over =item * MD5 - standard md5 algorithm =item * SHA-1 - SHA-1 algorithm =item * SHA-256 - SHA-2 algorithm with hash size of 256 bits =item * SHA-384 - SHA-2 algorithm with hash size of 384 bits =item * SHA-512 - SHA-2 algorithm with hash size of 512 bits =back If you'll choose to use checksums, for every type of checksum (you can specify --digest=MD5,SHA-512) there will be one additional file created, named just like data and xlog tarbals, but with __FILETYPE__ part of filename (details in L) changed to digest name. So, with filename template being __FILETYPE__.tar__CEXT__, gzip compression and MD5 checksumming, you will get 3 files: =over =item * data.tar.gz =item * xlog.tar.gz =item * MD5.tar.gz =back It is important to understand that the checksum file is plain text, and the parts of its name that suggest tar.gz as just "leftovers" from filename template. After creation, such checksum file can be verified with: md5sum -c MD5.tar.gz =head2 FILENAMES Naming of files for backups might be important depending on deployment. Generally, generated filenames are named using templates, with default template being: __HOSTNAME__-__FILETYPE__-^Y-^m-^d.tar__CEXT__ Within template (specified with --filename-template option) you can use following markers: =over =item * __HOSTNAME__ Name of server backup is made on - as reported by L program. =item * __FILETYPE__ It is actually required to have __FILETYPE__ - it specifies whether the file contains data (data) or xlog segments (xlog) =item * __CEXT__ Based on compression algorithm choosen for given delivery. Can be empty (no compression), or contains dot (.) and literal extension associated with choosen compression program. =item * any ^? markers like in L call, but ^ will be changed to % first. =back Filename template is evaluated at start, so any timestamp (^? markers) will relate to date/time of beginning of backup process. =head2 TABLESPACES If I detects additional tablespaces, they will be also compressed to generated tarball. Since the full path to the tablespace directory is important, and should be preserved, and normally tar doesn't let you store files which path starts with "/" (as it would be dangerous), I uses the following approach: all tablespaces will be stored in tar, and upon extraction they will be put in the directory "tablespaces", and under it - there will be the full path to the tablespace directory. For example: Assuming PostgreSQL PGDATA is in /var/lib/pgsql/data, and it has 3 extra tablespaces placed in: =over =item * /mnt/san/tablespace =item * /home/whatever/xxx =item * /media/ssd =back generated DATA tarball will contain 2 directories: =over =item * data - copy of /var/lib/pgsql/data =item * tablespaces - which contains full directory structure leading to: =over =item * tablespaces/mnt/san/tablespace - copy of /mnt/san/tablespace =item * tablespaces/home/whatever/xxx - copy of /home/whatever/xxx =item * tablespaces/media/ssd - copy of /media/ssd =back =back Thanks to this approach, if you'll create symlink "tablespaces" pointing to root directory (I) B exploding tarball - all tablespace files will be created already in the correct places. This is of course not necessary, but will help if you'd ever need to recover from such backup. =head2 EXAMPLES =head3 Minimal setup, with copying file to local directory: /.../omnipitr-backup-master -D /mnt/data -l /var/log/omnipitr/backup.log -dl /mnt/backups/ -x /mnt/dst-backup =head3 Minimal setup, with compression, and copying file to remote directory over rsync: /.../omnipitr-backup-master -D /mnt/data/ -l /var/log/omnipitr/backup.log -dr bzip2=rsync://slave/postgres/backups/ -x /mnt/dst-backup =head3 2 remote, compressed destinations, 1 local, with auto rotated logfile, and modified filenames /.../omnipitr-backup-master -D /mnt/data/ -l /var/log/omnipitr/backup-^Y-^m-^d.log -dr bzip2=rsync://slave/postgres/backups/ -dr gzip=backups:/mnt/hotbackups/ -dl /mnt/backups/ -f "main-__FILETYPE__-^Y^m^d_^H^M^S.tar__CEXT__" -x /mnt/dst-backup =head2 IMPORTANT NOTICES =over =item * It I will get stopped in B way (kill -9, or multiple ctrl-c - it is possible that it will leave database with backup mode still enabled. So, to prevent future problems with it, if you had to B stop it - remember to connect to postgresql and issue: SELECT pg_stop_backup(); =item * I should be running from the same system account as PostgreSQL. It is technically possible to make it work with running from another account, but it will definitely be more complicated and error-prone. =back =head2 COPYRIGHT The OmniPITR project is Copyright (c) 2009-2013 OmniTI. All rights reserved.