Merge pull request #3967 from XRPLF/wiki-migration-clio-disk-space

Add notes regarding disk space

docs/infrastructure/configuration/data-retention/configure-full-history.md

@@ -21,6 +21,13 @@ Acquiring full history from the peer-to-peer network takes a long time (several
 
 You do not need a full history server to participate in the network, validate transactions, or know the current state of the network. Full history is only useful for knowing the outcome of transactions that occurred in the past, or the state of the ledger at a given time in the past. To get such information, you must rely on other servers having the history you need.
 
+If you transfer a database dump via Amazon S3, keep in mind that S3 limits individual objects to about 5 TB. This can be smaller than a full-history `nudb.dat` file, so split the file into smaller pieces before uploading. For example:
+
+```
+split -b 1000000000000 --numeric-suffixes=1 nudb.dat /rippled/tmp/nudb.dat
+```
+
+A full dump consists of `ledger.db`, `transaction.db`, `nudb/nudb.key`, and the split `nudb/nudb.dat.*` pieces.
 
 ## Configuration Steps
 

docs/infrastructure/installation/install-clio-on-ubuntu.md

@@ -24,7 +24,7 @@ Before you install Clio, you must meet the following requirements.
 - Ensure that your system meets the [system requirements](system-requirements.md).
 
     {% admonition type="info" name="Note" %}
-    Clio has the same system requirements as the `xrpld` server, except Clio needs less disk space to store the same amount of ledger history.
+    Clio has the same system requirements as the `xrpld` server, except Clio needs less disk space to store the same amount of ledger history. To check the current disk usage of a running cluster, use `nodetool tablestats` or `du` on the Cassandra data directory. Since full history continuously grows, don't rely on a fixed estimate.
     {% /admonition %}
 
 - Access to a Cassandra cluster that is running locally or remote. You can choose to install and configure a Cassandra cluster manually by following the [Cassandra installation instructions](https://cassandra.apache.org/doc/latest/cassandra/getting_started/installing.html), or run Cassandra on a Docker container using one of the following commands.