-two NFS devices numbers over time. The solution implemented currently
-is to considers all NFS devices as being equal when it comes to
-comparing directories; this is fairly gross, but there does not seem
-to be a better way to go.
+two @acronym{NFS} devices numbers over time. The solution implemented
+currently is to considers all @acronym{NFS} devices as being equal
+when it comes to comparing directories; this is fairly gross, but
+there does not seem to be a better way to go.
+
+Apart from using @acronym{NFS}, there are a number of cases where
+relying on device numbers can cause spurious redumping of unmodified
+files. For example, this occurs when archiving @acronym{LVM} snapshot
+volumes. To avoid this, use @option{--no-check-device} option:
+
+@table @option
+@xopindex{no-check-device, described}
+@item --no-check-device
+Do not rely on device numbers when preparing a list of changed files
+for an incremental dump.
+
+@xopindex{check-device, described}
+@item --check-device
+Use device numbers when preparing a list of changed files
+for an incremental dump. This is the default behavior. The purpose
+of this option is to undo the effect of the @option{--no-check-device}
+if it was given in @env{TAR_OPTIONS} environment variable
+(@pxref{TAR_OPTIONS}).
+@end table