---
title: "tail emits warning: unrecognized file system type"
date: "2016-01-30"
category: "platform"
slug: "tail"
---

## Symptom

Running `tail` on [[determining-platform-version]] platforms opens the file successfully but produces a warning:

tail: unrecognized file system type 0x794c7630 for ‘error\_log’. please report this to bug-coreutils@gnu.org. reverting to polling

## Cause

Older versions of `tail` (shipped with RHEL 7.2) include a version of coreutils that does not recognize the OverlayFS filesystem magic number.

## Solution

This warning is safe to ignore. The `tail` command still works correctly, just falls back to polling mode. The issue has been [patched upstream](http://git.savannah.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=v8.24-111-g1118f32) in coreutils.
