Bug Fixes:
* Fixed an issue where keep-alives could be starved out by lots of small files during multi-threaded backup. They were also completely absent from single/multi-threaded backup resume and restore checksumming. (Reported by Janice Parkinson, Chris Barber.)
* Fixed an issue where the expire command would refuse to run when explicitly called from the command line if the db-host option was set. This was not an issue when expire was run automatically after a backup (Reported by Chris Barber.)
* Fixed an issue where validation was being running on archive_command even when the archive-check option was disabled.
Features:
* Added check command to validate that pgBackRest is configured correctly for archiving and backups. (Contributed by Cynthia Shang.)
* Added the protocol-timeout option. Previously protocol-timeout was set as db-timeout + 30 seconds.
* Failure to shutdown remotes at the end of the backup no longer throws an exception. Instead a warning is generated that recommends a higher protocol-timeout.
* Experimental support for non-exclusive backups in PostgreSQL 9.6 beta2. Changes to the control/catalog/WAL versions in subsequent betas may break compatibility but pgBackRest will be updated with each release to keep pace.
Refactoring:
* The pg_xlogfile_name() function is no longer used to construct WAL filenames from LSNs. While this function is convenient it is not available on a standby. Instead, the archive is searched for the LSN in order to find the timeline. If due to some misadventure the LSN appears on multiple timelines then an error will be thrown, whereas before this condition would have passed unnoticed.
* Option handling is now far more strict. Previously it was possible for a command to use an option that was not explicitly assigned to it. This was especially true for the backup-host and db-host options which are used to determine locality.
* Improved handling of users/groups captured during backup that do not exist on the restore host. Also explicitly handle the case where user/group is not mapped to a name.
* Changed version variable to a constant. It had originally been designed to play nice with a specific packaging tool but that tool was never used.
Improved handling of users/groups captured during backup that do not exist on the restore host. Also explicitly handle the case where user/group is not mapped to a name.
* Make the code more modular and object-oriented.
* Multiple Docker containers can now be created for a single test to simulate more realistic environments.
The pg_xlogfile_name() function is no longer used to construct WAL filenames from LSNs. While this function is convenient it is not available on a standby. Instead, the archive is searched for the LSN in order to find the timeline. If due to some misadventure the LSN appears on multiple timelines then an error will be thrown, whereas before this condition would have passed unnoticed.
* Fixed an issue where keep-alives could be starved out by lots of small files during multi-threaded operation and were completely absent during single-threaded operation when resuming from a previous incomplete backup.
Reported by Janice Parkinson.
* Added the protocol-timeout option. Previously protocol-timeout was set as db-timeout + 30 seconds.
* Failure to shutdown remotes at the end of the backup no longer throws an exception. A warning is still generated that recommends a higher protocol-timeout.
* Fixed an issue where the expire command would refuse to run when explicitly called from the command line if the db-host option was set. This was not an issue when expire was run after a backup, which is the usual case.
* Option handling is now far more strict. Previously it was possible for a command to use an option that was not explicitly assigned to it. This was especially true for the backup-host and db-host options which are used to determine locality.
Reported by Chris Barber.
* Fix usage of sprintf() due to new constraints in Perl 5.22. Parameters not referenced in the format string are no longer allowed. (Fixed by Adrian Vondendriesch.)
* Enhanced text output of `info` command to include timestamps, sizes, and the reference list for all backups. Contributed by Cynthia Shang.
* Allow selective restore of databases from a cluster backup. This feature can result in major space and time savings when only specific databases are restored. Unrestored databases will not be accessible but must be manually dropped before they will be removed from the shared catalogue.
* Experimental support for non-exclusive backups in PostgreSQL 9.6 beta1. Changes to the control/catalog/WAL versions in subsequent betas may break compatibility but pgBackRest will be updated with each release to keep pace.
Some files need to be added to the manifest after the initial build. This is currently done in only one place but usage will expand in the future so the functionality has been encapsulated in addFile().
Added database version constants and changed version identification code to use hash tables instead of if-else. Propagated the db version constants to the rest of the code and in passing fixed some path/filename constants.
Added new regression tests to check that specific files are never copied.
The join() used was not able to handle nulls and was replaced by a loop. An injudicious trim was removed when the source of extra linefeeds was determined to be an additional loop execution that was not handled correctly.
This feature can result in major space and time savings when only specific databases are restored. Unrestored databases will not be accessible but must be manually dropped before they will be removed from the shared catalogue.
* This flag day release breaks compatibility with older versions of pgBackRest. The manifest format, on-disk structure, configuration scheme, and the exe/path names have all changed. You must create a new repository to hold backups for this version of pgBackRest and keep your older repository for a time in case you need to do a restore. Restores from the prior repository will require the prior version of pgBackRest but because of name changes it is possible to have 1.00 and a prior version of pgBackRest installed at the same time. See the notes below for more detailed information on what has changed.
* Implemented a new configuration scheme which should be far simpler to use. See the User Guide and Configuration Reference for details but for a simple configuration all options can now be placed in the stanza section. Options that are shared between stanzas can be placed in the [global] section. More complex configurations can still make use of command sections though this should be a rare use case.
* The repo-path option now always refers to the repository where backups and archive are stored, whether local or remote, so the repo-remote-path option has been removed. The new spool-path option can be used to define a location for queueing WAL segments when archiving asynchronously. A local repository is no longer required.
* The default configuration filename is now pgbackrest.conf instead of pg_backrest.conf. This was done for consistency with other naming changes but also to prevent old config files from being loaded accidentally when migrating to 1.00.
* The default repository name was changed from /var/lib/backup to /var/lib/pgbackrest.
* Lock files are now stored in /tmp/pgbackrest by default. These days /run/pgbackrest is the preferred location but that would require init scripts which are not part of this release. The lock-path option can be used to configure the lock directory.
* Log files are now stored in /var/log/pgbackrest by default and no longer have the date appended so they can be managed with logrotate. The log-path option can be used to configure the lock directory.
* Executable filename changed from pg_backrest to pgbackrest.
* All files and directories linked from PGDATA are now included in the backup. By default links will be restored directly into PGDATA as files or directories. The --link-all option can be used to restore all links to their original locations. The --link-map option can be used to remap a link to a new location.
* Removed --tablespace option and replaced with --tablespace-map-all option which should more clearly indicate its function.
* Added detail log level which will output more information than info without being as verbose as debug.
* All files and directories linked from PGDATA are now included in the backup. By default links will be restored directly into PGDATA as files or directories. The --link-all option can be used to restore all links to their original locations. The --link-map option can be used to remap a link to a new location.
* Removed --tablespace option and replaced with --tablespace-map-all option which should more clearly indicate its function.
* Added detail log level which will output more information than info without being as verbose as debug.
* The repo-path option now always refers to the repository where backups and archive are stored, whether local or remote, so the repo-remote-path option has been removed. The new spool-path option can be used to define a location for queueing WAL segments when archiving asynchronously. Otherwise, a local repository is no longer required.
* Implemented a new config format which should be far simpler to use. See the User Guide and Configuration Reference for details but for a simple configuration all options can now be placed in the stanza section. Options that are shared between stanzas can be placed in the [global] section. More complex configurations can still make use of command sections though this should be a rare use case.
* The default configuration filename is now pgbackrest.conf instead of pg_backrest.conf. This was done for consistency with other naming changes but also to prevent old config files from being loaded accidentally.
* The default repository name was changed from /var/lib/backup to /var/lib/pgbackrest.
* Lock files are now stored in /tmp/pgbackrest by default. These days /run/pgbackrest would be the preferred location but that would require init scripts which are not part of this release. The lock-path option can be used to configure the lock directory.
* Log files are now stored in /var/log/pgbackrest by default and no longer have the date appended so they can be managed with logrotate. The log-path option can be used to configure the lock directory.
* Executable filename changed from pg_backrest to pgbackrest.
This makes make the migrated file functions available to parts of the code that don't have access to a File object. They still exist as wrappers in the File object to support remote calls.
In conditions where an error is known to have occurred wait to try and capture the error in the first call that detects the error. Due to timing sometimes the error could be caught later, which worked, but it made the functionality inconsistent in testing.
* Fixed an issue where the master process was passing --repo-remote-path instead of --repo-path to the remote and causing the lock files to be created in the default repository directory (/var/lib/backup), generally ending in failure. This was only an issue when --repo-remote-path was defined on the command line rather than in pg_backrest.conf. Reported by Jan Wieck.
Fixed an issue where the master process was passing --repo-remote-path instead of --repo-path to the remote and causing the lock files to be created in the default repository directory (/var/lib/backup), generally ending in failure. This was only an issue when --repo-remote-path was defined on the command line rather than in pg_backrest.conf.
* **IMPORTANT BUG FIX FOR TABLESPACES**: A change to the repository format was accidentally introduced in 0.90 which means the on-disk backup was no longer a valid PostgreSQL cluster when the backup contained tablespaces. This only affected users who directly copied the backups to restore PostgreSQL clusters rather than using the restore command. However, the fix breaks compatibility with older backups that contain tablespaces no matter how they are being restored (pgBackRest will throw errors and refuse to restore). New full backups should be taken immediately after installing version 0.91 for any clusters that contain tablespaces. If older backups need to be restored then use a version of pgBackRest that matches the backup version. _Reported by Evan Benoit_.
* Copy global/pg_control last during backups.
* Write .info and .manifest files to temp before moving them to their final locations and fsync'ing.
* Rename --no-start-stop option to --no-online.
* Static source analysis using Perl-Critic, currently passes on gentle.
This erroneous last caused a warning (which threw an error) and masked the error in decompression. It was found when accidentally attempting to decompress an already-decompressed file, so not a big deal in practice which is probably why it hug around for so long.
Perl Critic added and passes on gentle. A policy file has been created with some permanent exceptions and a list of policies to be fixed in approximately the order they should be fixed in.
* Fixed an issue where specifying --no-archive-check would throw a configuration error. Reported by Jason O'Donnell.
* Fixed an issue where a temp WAL file left over after a well-timed system crash could cause the next archive-push to fail.
* Fixed an issue where document generation failed because some OSs are not tolerant of having multiple installed versions of PostgreSQL. A separate VM is now created for each version. Also added a sleep after database starts during document generation to ensure the database is running before the next command runs. Reported by John Harvey.
* The retention-archive option can now be be safely set to less than backup retention (retention-full or retention-diff) without also specifying archive-copy=n. The WAL required to make the backups that fall outside of archive retention consistent will be preserved in the archive. However, in this case PITR will not be possible for the backups that fall outside of archive retention.
* When backing up and restoring tablespaces pgBackRest only operates on the subdirectory created for the version of PostgreSQL being run against. Since multiple versions can live in a tablespace (especially during a binary upgrade) this prevents too many files from being copied during a backup and other versions possibly being wiped out during a restore. This only applies to PostgreSQL >= 9.0 -- prior versions of PostgreSQL could not share a tablespace directory.
* Generate an error when archive-check=y but archivecommand does not execute pgbackrest. Contributed by Jason O'Donnell.
* Improved error message when repo-path or repo-remote-path does not exist.
* Added checks for --delta and --force restore options to ensure that the destination is a valid $PGDATA directory. pgBackRest will check for the presence of PGVERSION or backup.manifest (left over from an aborted restore). If neither file is found then --delta and --force will be disabled but the restore will proceed unless there are files in the $PGDATA directory (or any tablespace directories) in which case the operation will be aborted.
* When restore --set=latest (the default) the actual backup restored will be output to the log.
* Support for PostgreSQL 9.5 partial WAL segments and recoverytargetaction setting. The archivemode = 'always' setting is not yet supported.
* Support for recoverytarget = 'immediate' recovery setting introduced in PostgreSQL 9.4.
* The following tablespace checks have been added: paths or files in pgtblspc, relative links in pgtblspc, tablespaces in $PGDATA. All three will generate errors.
Added checks for `--delta` and `--force` restore options to ensure that the destination is a valid $PGDATA directory. pgBackRest will check for the presence of `PG_VERSION` or `backup.manifest` (left over from an aborted restore). If neither is found then `--delta` and `--force` will be disabled but the restore will proceed unless there are files in the $PGDATA directory (or any tablespace directories) in which case the operation will be aborted.
When backing up and restoring tablespaces pgBackRest only operates on the subdirectory created for the version of PostgreSQL being run against. Since multiple versions can live in a tablespace (especially during a binary upgrade) this prevents too many files from being copied during a backup and other versions possibly being wiped out during a `--delta` restore. This only applies to PostgreSQL >= 9.0 -- before that only one PostgreSQL version could use a tablespace.
1) Tests for all operating systems can now be run with a single command.
2) Tests can be run in parallel with --process-max.
3) Container generation now integrated into test.pl
4) Some basic test documentation.
* Fixed an issue where longer-running backups/restores would timeout when remote and threaded. Keepalives are now used to make sure the remote for the main process does not timeout while the thread remotes do all the work. The error message for timeouts was also improved to make debugging easier.
* Allow restores to be performed on a read-only repository by using --no-lock and --log-level-file=off. The --no-lock option can only be used with restores.
* Minor styling changes, clarifications and rewording in the user guide.
* The dev branch has been renamed to master and for the time being the master branch has renamed to release, though it will probably be removed at some point -- thus ends the gitflow experiment for pgBackRest. It is recommended that any forks get re-forked and clones get re-cloned.
Keepalives are now used to make sure the remote for the main process does not timeout while the thread remotes do all the work. The error messages for timeouts was also improved to make debugging easier.
1) Started on a general markdown renderer
2) Internal links now work in PDF
3) Improvements to PDF styling
4) Some comment and formatting fixes
5) User guide edits.
* Better messaging for expiration.
* Fixed already stopped message.
* retention-archive and retention-archive-type now use retention-full and 'full' when not specified.
* Fixed issue where backup-user was required (should default to backrest).
* ExecuteTest now supports retries.
* Fixed issue where log test was not comparing test logs.
* Fixed issue where test logs would not match for ssh connection errors
* Added a new user guide that covers pgBackRest basics and some advanced topics including PITR. Much more to come, but it's a start.
* The website, markdown, and command-line help are now all generated from the same XML source.
* The backup_label.old and recovery.done files are now excluded from backups.
* Added new feature to allow all pgBackRest operations to be stopped or started using the stop and start commands. This prevents any pgBackRest processes from running on a system where PostgreSQL is shutdown or the system needs to be quiesced for some reason.
* Removed dependency on IO::String module.
* Fixed an issue where an error could be returned after a backup or restore completely successfully.
* Fixed an issue where a resume would fail if temp files were left in the root backup directory when the backup failed. This scenario was likely if the backup process got terminated during the copy phase.
* Experimental support for PostgreSQL 9.5 beta1. This may break when the control version or WAL magic changes in future versions but will be updated in each pgBackRest release to keep pace. All regression tests pass except for --target-resume tests (this functionality has changed in 9.5) and there is no testing yet for .partial WAL segments.
* Fixed an issue where resumed compressed backups were not preserving existing files.
* Fixed an issue where resume and incr/diff would not ensure that the prior backup had the same compression and hardlink settings.
* Fixed an issue where a cold backup using --no-start-stop could be started on a running PostgreSQL cluster without --force specified.
* Fixed an issue where a thread could be started even when none were requested.
* Fixed an issue where the pgBackRest version number was not being updated in backup.info and archive.info after an upgrade/downgrade.
* Fixed an issue where the info command was throwing an exception when the repository contained no stanzas. Reported by Stephen Frost.
* Fixed an issue where the PostgreSQL pg_stop_backup() NOTICEs were being output to stderr. Reported by Stephen Frost.
* Renamed recovery-setting option and section to recovery-option to be more consistent with pgBackRest naming conventions.
* Command-line help is now extracted from the same XML source that is used for the other documentation and includes much more detail.
* Code cleanup and refactoring to standardize on patterns that have evolved over time.
* Added dynamic module loading to speed up commands, especially asynchronous archiving.
* Expiration tests are now synthetic rather than based on actual backups. This will allow development of more advanced expiration features.
* Experimental support for PostgreSQL 9.5 alpha2. This may break when the control version or WAL magic changes in future versions but will be updated in each pgBackRest release to keep pace. All regression tests pass except for --target-resume tests (this functionality has changed in 9.5) and there is no testing yet for .partial WAL segments.
Unable to reproduce this anymore. It seems to have been fixed with the last round of config changes. Add regression tests to make sure it doesn't happen again.
* Fixed an issue that caused the formatted timestamp for both the oldest and newest backups to be reported as the current time by the info command. Only text output was affected -- json output reported the correct epoch values. Reported by Michael Renner.
* Fixed protocol issue that was preventing ssh errors (especially on connection) from being logged.
* Now using Perl DBI and DBD::Pg for connections to PostgreSQL rather than psql. The cmd-psql and cmd-psql-option settings have been removed and replaced with db-port and db-socket-path.
* Add stop-auto option to allow failed backups to automatically be stopped when a new backup starts.
* Add db-timeout option to limit the amount of time pgBackRest will wait for pg_start_backup() and pg_stop_backup() to return.
* Remove pg_control file at the beginning of the restore and copy it back at the very end. This prevents the possibility that a partial restore can be started by PostgreSQL.
* The repository is now created and updated with consistent directory and file modes. By default umask is set to 0000 but this can be disabled with the neutral-umask setting.
* Added checks to be sure the db-path setting is consistent with db-port by comparing the data_directory as reported by the cluster against the db-path setting and the version as reported by the cluster against the value read from pg_control. The db-socket-path setting is checked to be sure it is an absolute path.
* Experimental support for PostgreSQL 9.5 alpha1. This may break when the control version or WAL magic changes in future versions but will be updated in each pgBackRest release to keep pace. All regression tests pass except for --target-resume tests (this functionality has changed in 9.5) and there is no testing yet for .partial WAL segments.
* Major refactoring of the protocol layer to support future development.
* Added vagrant test configurations for Ubuntu 14.04 and CentOS 7.
* Split most of README.md out into USERGUIDE.md and CHANGELOG.md because it was becoming unwieldy. Changed most references to "database" in the user guide to "database cluster" for clarity.
Most tests are working now. What's not working:
1) --target-resume option fails because pause_on_recovery setting was removed. Need to implement to the new 9.5 option and make that work with older versions in a consistent way.
2) No tests for the new .partial WAL segments that can be generated on timeline switch.
* Major refactoring of the protocol layer to support this work.
* Fixed protocol issue that was preventing ssh errors (especially connect) from being logged.
On some systems the JSON->encode() function was adding a linefeed and on others it was not. This was causing regression test failures in in the test logs and may have also been inconvenient for users.
* Removed dependency on CPAN packages for multi-threaded operation. While it might not be a bad idea to update the threads and Thread::Queue packages, it is no longer necessary.
* Added vagrant test configurations for Ubuntu 12.04 and CentOS 6.
* Modified wait backoffs to use a Fibonacci sequence rather than geometric. This will make then grow less aggressively while still giving reasonable wait times.
* More options for regression tests and improved code to run in a variety of environments.
* Removed pg_backrest_remote and added the functionality to pg_backrest as remote command.
* Added file and directory syncs to the File object for additional safety during backup/restore and archiving. Suggested by Andres Freund.
* Support for Perl 5.10.1 and OpenSSH 5.3 which are default for CentOS/RHEL 6. Found by Eric Radman.
* Improved error message when backup is run without archive_command set and without --no-archive-check specified. Found by Eric Radman.
* Moved version number out of the VERSION file to Version.pm to better support packaging. Suggested by Michael Renner.
* Replaced IPC::System::Simple and Net::OpenSSH with IPC::Open3 to eliminate CPAN dependency for multiple distros.
Replaced IPC::System::Simple and Net::OpenSSH with IPC::Open3 to eliminate CPAN dependency for multiple distros. Using open3 will also be used for local processes so it make sense to switch now.
Also stopped replacing FORMAT number which explains the large number of test log changes. FORMAT should change very rarely and cause test log failures when it does.
More separation of the protocol and remote layers than was done in issue #106.
Settings are passed to the remote via command-line parameters rather than in the protocol.
* IMPORTANT NOTE: This flag day release breaks compatibility with older versions of PgBackRest. The manifest format, on-disk structure, and the binary names have all changed. You must create a new repository to hold backups for this version of PgBackRest and keep your older repository for a time in case you need to do a restore. The `pg_backrest.conf` file has not changed but you'll need to change any references to `pg_backrest.pl` in cron (or elsewhere) to `pg_backrest` (without the `.pl` extension).
* Add info command.
* More efficient file ordering for backup. Files are copied in descending size order so a single thread does not end up copying a large file at the end. This had already been implemented for restore.
* Logging now uses unbuffered output. This should make log files that are being written by multiple threads less chaotic. Suggested by Michael Renner.
* Experimental support for PostgreSQL 9.5. This may break when the control version or WAL magic changes but will be updated in each release.
* Includes updating the manifest to format 4. It turns out the manifest and .info files were not very good for providing information. A format update was required anyway so worked through the backlog of changes that would require a format change.
* Multiple database versions are now supported in the archive. Does't actually work yet but the structure should be good.
* Tests use more constants now that test logs can catch name regressions.
* Fixed an issue where archive-copy would fail on an incr/diff backup when hardlink=n. In this case the pg_xlog path does not already exist and must be created. Reported by Michael Renner
* Allow duplicate WAL segments to be archived when the checksum matches. This is necessary for some recovery scenarios.
* Allow comments/disabling in pg_backrest.conf using #. Suggested by Michael Renner.
* Better logging before pg_start_backup() to make it clear when the backup is waiting on a checkpoint. Suggested by Michael Renner.
* Various command behavior, help and logging fixes. Reported by Michael Renner.
* Fixed an issue in async archiving where archive-push was not properly returning 0 when archive-max-mb was reached and moved the async check after transfer to avoid having to remove the stop file twice. Also added unit tests for this case and improved error messages to make it clearer to the user what went wrong. Reported by Michael Renner.
* Fixed a locking issue that could allow multiple operations of the same type against a single stanza. This appeared to be benign in terms of data integrity but caused spurious errors while archiving and could lead to errors in backup/restore. Reported by Michael Renner.
* Replaced JSON module with JSON::PP which ships with core Perl.
ASSERTs still dump stack traces to the console and file in all cases. ERRORs only dump stack traces to the file when the file log level is DEBUG or TRACE.
* Better resume support. Resumed files are checked to be sure they have not been modified and the manifest is saved more often to preserve checksums as the backup progresses. More unit tests to verify each resume case.
* Resume is now optional. Use the `resume` setting or `--no-resume` from the command line to disable.
* More info messages during restore. Previously, most of the restore messages were debug level so not a lot was output in the log.
* Fixed an issue where an absolute path was not written into recovery.conf when the restore was run with a relative path.
* Added `tablespace` setting to allow tablespaces to be restored into the `pg_tblspc` path. This produces compact restores that are convenient for development, staging, etc. Currently these restores cannot be backed up as PgBackRest expects only links in the `pg_tblspc` path.
1) Re-checksums files that have checksums in the manifest
2) Recopies files that do not have a checksum
3) Saves the manifest at regular intervals to preserve checksums
4) Unit tests for all cases (that I can think of)
* Fixed a buffering error that could occur on large, highly-compressible files when copying to an uncompressed remote destination. The error was detected in the decompression code and resulted in a failed backup rather than corruption so it should not affect successful backups made with previous versions.
* Pushing duplicate WAL now generates an error. This worked before only if checksums were disabled.
* Database System IDs are used to make sure that all WAL in an archive matches up. This should help prevent misconfigurations that send WAL from multiple clusters to the same archive.
* Regression tests working back to PostgreSQL 8.3.
* Improved threading model by starting threads early and terminating them late.
* Added restore functionality.
* All options can now be set on the command-line making pg_backrest.conf optional.
* De/compression is now performed without threads and checksum/size is calculated in stream. That means file checksums are no longer optional.
* Added option `--no-start-stop` to allow backups when Postgres is shut down. If `postmaster.pid` is present then `--force` is required to make the backup run (though if Postgres is running an inconsistent backup will likely be created). This option was added primarily for the purpose of unit testing, but there may be applications in the real world as well.
* Fixed broken checksums and now they work with normal and resumed backups. Finally realized that checksums and checksum deltas should be functionally separated and this simplied a number of things. Issue #28 has been created for checksum deltas.
* Fixed an issue where a backup could be resumed from an aborted backup that didn't have the same type and prior backup.
* Removed dependency on Moose. It wasn't being used extensively and makes for longer startup times.
* Checksum for backup.manifest to detect corrupted/modified manifest.
* Link `latest` always points to the last backup. This has been added for convenience and to make restores simpler.
* More comprehensive unit tests in all areas.
* Complete rewrite of BackRest::File module to use a custom protocol for remote operations and Perl native GZIP and SHA operations. Compression is performed in threads rather than forked processes.
* Fairly comprehensive unit tests for all the basic operations. More work to be done here for sure, but then there is always more work to be done on unit tests.
* Removed dependency on Storable and replaced with a custom ini file implementation.
* Added much needed documentation (see INSTALL.md).
* Numerous other changes that can only be identified with a diff.
