add notice about defective hardware to check documentation (#5753)

docs/usage/check.rst.inc

@@ -87,6 +87,11 @@ The check command verifies the consistency of a repository and the corresponding
 check --repair is a potentially dangerous function and might lead to data loss
 (for kinds of corruption it is not capable of dealing with). BE VERY CAREFUL!
 
+Pursuant to the previous warning it is also highly recommended to test the
+reliability of the hardware running this software with stress testing software
+such as memory testers. Unreliable hardware can also lead to data loss especially
+when this command is run in repair mode.
+
 First, the underlying repository data files are checked:
 
 - For all segments, the segment magic header is checked.