[update] Backup and restore (#2038)

* added ts and a note for pg_dumpall

* minor edits

_troubleshooting/timescaledb/pg_restore-errors.md

@@ -0,0 +1,22 @@
+---
+title: Errors occur after restoring from file dump 
+section: troubleshooting
+topics: [backups]
+errors:
+  - language: bash
+    message: |-
+      org.postgresql.util.PSQLException: ERROR: invalid INSERT on the root table of hypertable "_hyper_1_10_chunk.
+keywords: [backups, restore]
+---
+
+<!---
+* Use this format for writing troubleshooting sections:
+ - Cause: What causes the problem?
+ - Consequence: What does the user see when they hit this problem?
+ - Fix/Workaround: What can the user do to fix or work around the problem? Provide a "Resolving" Procedure if required.
+ - Result: When the user applies the fix, what is the result when the same action is applied?
+* Copy this comment at the top of every troubleshooting page
+-->
+ You might see the errors above when running `pg_restore`. When loading from a
+ logical dump make sure that you set `timescaledb.restoring` to true before loading
+ the dump.

timescaledb/how-to-guides/backup-and-restore/pg-dump-and-restore.md

@@ -162,10 +162,18 @@ partitions, or the chunk interval sizes.
 
 </procedure>
 
+On a self hosted TimescaleDB instance with `postgres` superuser access you can
+take a complete dump of all PostgreSQL databases in a cluster including global
+objects that are common to all databases, namely database roles, tablespaces,
+and privilege grants using `pg_dumpall`. For more
+information about how to use the `pg_dumpall` utility, see
+[PostgreSQL documentation][postgres-docs].  
+
 [parallel importer]: https://github.com/timescale/timescaledb-parallel-copy
 [pg_dump]: https://www.postgresql.org/docs/current/static/app-pgdump.html
 [pg_restore]: https://www.postgresql.org/docs/current/static/app-pgrestore.html
 [timescaledb_pre_restore]: /api/:currentVersion:/administration/timescaledb_pre_restore/
 [timescaledb_post_restore]: /api/:currentVersion:/administration/timescaledb_post_restore/
 [timescaledb-upgrade]: /timescaledb/:currentVersion:/how-to-guides/upgrades/
 [troubleshooting]: /timescaledb/:currentVersion:/how-to-guides/backup-and-restore/troubleshooting/
+[postgres-docs]: https://www.postgresql.org/docs/current/app-pg-dumpall.html