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8.3 Ensure the backup and restore tool, 'pgBackRest', is installed and configured
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pgBackRest aims to be a simple, reliable backup and restore system that can seamlessly scale up to the largest databases and workloads. Instead of relying on traditional backup tools like tar and rsync, pgBackRest implements all backup features internally and uses a custom protocol for communicating with remote systems. Removing reliance on tar and rsync allows for better solutions to database-specific backup challenges. The custom remote protocol allows for more flexibility and limits the types of connections that are required to perform a backup which increases security.Rationale:
The native PostgreSQL backup facility pg_dump provides adequate logical backup operations but does not provide for Point In Time Recovery (PITR). The PostgreSQL facility pg_basebackup performs physical backup of the database files and does provide for PITR, but it is constrained by single threading. Both of these methodologies are standard in the PostgreSQL ecosystem and appropriate for particular backup/recovery needs. pgBackRest offers another option with much more robust features and flexibility.
pgBackRest is open source software developed to perform efficient backup on PostgreSQL databases that measure in tens of terabytes and greater. It supports per file checksums, compression, partial/failed backup resume, high-performance parallel transfer, asynchronous archiving, tablespaces, expiration, full/differential/incremental, local/remote operation via SSH, hard-linking, restore, and more. pgBackRest is written in Perl and does not depend on rsync or tar but instead performs its own deltas which gives it maximum flexibility. Finally, pgBackRest provides an easy to use internal repository listing backup details accessible via the pgbackrest info command, as illustrated below.
$ pgbackrest info
stanza: proddb01
status: ok
db (current)
wal archive min/max (9.5-1): 00000008000098E000000036 /
0000000800009953000000BB
full backup: 20171028-080001F
timestamp start/stop: 2017-10-28 08:00:01 / 2017-10-28 12:04:21
wal start/stop: 00000008000098E000000036 / 00000008000098E100000076
database size: 2218.1GB, backup size: 2218.1GB
repository size: 417.3GB, repository backup size: 417.3GB
full backup: 20171104-080001F
timestamp start/stop: 2017-11-04 08:00:01 / 2017-11-04 12:20:00
wal start/stop: 0000000800009934000000B9 / 000000080000993600000008
database size: 2225.6GB, backup size: 2225.6GB
repository size: 418.8GB, repository backup size: 418.8GB
NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
Solution
pgBackRest installation is rather simple and straightforward. All steps below must be performed as postgres with appropriate sudo privileges granted.Install required perl libraries
$ sudo yum -y install libdbd-pg-perl libio-socket-ssl-perl libxml-libxml-perl
Download the project from GitHub
$ sudo wget -q -O -
https://github.com/pgbackrest/pgbackrest/archive/release/1.25.tar.gz |
sudo tar zx -C /root
Install pgBackRest
$ sudo cp -r /root/pgbackrest-release-1.25/lib/pgBackRest
/usr/share/perl5
$ sudo find /usr/share/perl5/pgBackRest -type f -exec chmod 644 {} +
$ sudo find /usr/share/perl5/pgBackRest -type d -exec chmod 755 {} +
$ sudo cp /root/pgbackrest-release-1.25/bin/pgbackrest /usr/bin/pgbackrest
$ sudo chmod 755 /usr/bin/pgbackrest
$ sudo mkdir -m 770 /var/log/pgbackrest
$ sudo chown postgres:postgres /var/log/pgbackrest
$ sudo touch /etc/pgbackrest.conf
$ sudo chmod 640 /etc/pgbackrest.conf
$ sudo chown postgres:postgres /etc/pgbackrest.conf
Once installed, pgBackRest must be configured for things like stanza name, backup location, retention policy, logging, etc. Please consult the configuration guide.
If employing pgBackRest for your backup/recovery solution, ensure the repository, base backups, and WAL archives are stored on a reliable file system separate from the database server. Further, the external storage system where backups resided should have limited access to only those system administrators as necessary. Finally, as with any backup/recovery solution, stringent testing must be conducted. A backup is only good if it can be restored successfully.
See Also
Item Details
Audit Name: CIS PostgreSQL 9.5 OS v1.0.0
Category: CONTINGENCY PLANNING
References: 800-53|CP-9, CSCv6|10
Plugin: Unix
Control ID: 8a11ff8b505921e971052d17a163619569f3e8ee98e25233082776fd7f3377b9