diff options
| -rw-r--r-- | cmds-filesystem.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/cmds-filesystem.c b/cmds-filesystem.c index c39f2d15..46aa4973 100644 --- a/cmds-filesystem.c +++ b/cmds-filesystem.c @@ -893,6 +893,11 @@ static const char * const cmd_filesystem_defrag_usage[] = { "-s start defragment only from byte onward", "-l len defragment only up to len bytes", "-t size target extent size hint (default: 32M)", + "", + "Warning: most Linux kernels will break up the ref-links of COW data", + "(e.g., files copied with 'cp --reflink', snapshots) which may cause", + "considerable increase of space usage. See btrfs-filesystem(8) for", + "more information.", NULL }; |