Call Us! 1-800-383-5193
Call Us! 1-800-383-5193
Call Us! 1-800-383-5193

Need Help?

Emergency Response Time custom

Our experts have had an average response time of 11.06 minutes in March 2021 to fix urgent issues.

We will keep your servers stable, secure and fast at all times for one fixed price.

Solutions for ‘error 15 file not found’ in CentOS servers

by | Oct 24, 2018

Kernel updates are vital for security and feature additions. But if not performed with caution, these updates can render your server unavailable or down.

In our role as Outsourced Tech Support services for web hosts, kernel updates are a commonly performed task in servers.

Today, we’ll discuss the error ‘Error 15: File not Found’ that occurs in CentOS servers when trying to boot after changes in grub.

‘Error 15 file not found’ in CentOS server – Causes

The error ‘Error 15: File not found’ happens when you try to boot a server with the updated kernel after a kernel update or patch.

Error 15: File not Found

Press any key to continue


This error is caused due to some issues with the GRUB, which is the boot loader used in CentOS servers.

The main reasons why you get this error 15 are:

1. Wrong entries in GRUB

In majority scenarios, the ‘Error 15: File not Found’ issue pops up due to an incorrect entry in the GRUB boot loader configuration file at  /boot/grub/menu.lst .

A typical entry in GRUB menu for CentOS 6 servers looks like:

title CentOS (2.6.18-238.19.1.el5PAE)
root (hd0,0)
kernel /vmlinuz-2.6.18-238.19.1.el5PAE ro root=LABEL=/
initrd /initrd-2.6.18-238.19.1.el5PAE.img
title CentOS (2.6.18-238.9.1.el5PAE)


The cause for the error 15 can be anything from an incorrect drive, wrong path or partition name, or any other mistakes in this kernel entry in the GRUB menu.

By default, the kernel images are found in /boot partition. In servers where the partition system is different, these paths have to be changed accordingly in GRUB menu.

2. Corrupt GRUB configuration file

A GRUB configuration can get corrupt during system updates. When GRUB is installed in the wrong partition, the system will not be able to boot at all.

If the required modules are missing in the expected /boot partition, system cannot boot. The MBR (Master Boot Record) can get damaged when a secondary OS is installed.

In some cases, the initrd declaration or kernel path may be missing for any listed kernels in the GRUB menu. This will prevent the server from booting into that kernel.

3. Defective hard disk

“Error 15 file not found” may also occur in CentOS servers due to change in BIOS settings, changes in hardware or errors in hard disk.

In the case of servers with multiple hard disks or OS installations, there are chances of creating multiple boot partitions and GRUB mixing up between them.

‘Error 15 file not found’ in CentOS server – Fixes

Depending on the scenario faced and the level of access to the server, we follow different methodologies to fix the error 15.

1. Fixing GRUB entries

When customers contact us saying their server fails to boot due to Error 15, we boot the server into rescue mode and access it via remote console such as IPMI or web portal.

Once the boot prompt loads, we edit the GRUB entries and fix the error. In cases where GRUB is fully corrupt, we reinstall the bootstrap code and then boot the server.

2. Test reboots

In the server where we perform kernel updates or patches, we take adequate backups. We configure GRUB with a fail-over entry to avoid a boot failure.

This fall back configuration ensures that even if a new kernel doesn’t boot due to any errors, there is a fall back working kernel entry which will boot and make the server available.

3. Hard disk inspection

To rule out ‘error 15 file not found’ in CentOS servers due to hard disk errors, we conduct periodic audits to see if there are any bad sectors or other errors.

For servers with messed up hard disks or OS installations, we backup the data and perform re-partition or re-installation as necessary, to fix the errors.


GRUB errors pop up mainly during kernel updates. Today we saw how our Support Engineers resolve and fix ‘Error 15 file not found’ in CentOS servers.



Never again lose customers to poor server speed! Let us help you.

Our server experts will monitor & maintain your server 24/7 so that it remains lightning fast and secure.


var google_conversion_label = "owonCMyG5nEQ0aD71QM";


Submit a Comment

Your email address will not be published. Required fields are marked *

Privacy Preference Center


Necessary cookies help make a website usable by enabling basic functions like page navigation and access to secure areas of the website. The website cannot function properly without these cookies.

PHPSESSID - Preserves user session state across page requests.

gdpr[consent_types] - Used to store user consents.

gdpr[allowed_cookies] - Used to store user allowed cookies.

PHPSESSID, gdpr[consent_types], gdpr[allowed_cookies]


Statistic cookies help website owners to understand how visitors interact with websites by collecting and reporting information anonymously.

_ga - Preserves user session state across page requests.

_gat - Used by Google Analytics to throttle request rate

_gid - Registers a unique ID that is used to generate statistical data on how you use the website.

smartlookCookie - Used to collect user device and location information of the site visitors to improve the websites User Experience.

_ga, _gat, _gid
_ga, _gat, _gid


Marketing cookies are used to track visitors across websites. The intention is to display ads that are relevant and engaging for the individual user and thereby more valuable for publishers and third party advertisers.

IDE - Used by Google DoubleClick to register and report the website user's actions after viewing or clicking one of the advertiser's ads with the purpose of measuring the efficacy of an ad and to present targeted ads to the user.

test_cookie - Used to check if the user's browser supports cookies.

1P_JAR - Google cookie. These cookies are used to collect website statistics and track conversion rates.

NID - Registers a unique ID that identifies a returning user's device. The ID is used for serving ads that are most relevant to the user.

DV - Google ad personalisation

IDE, test_cookie, 1P_JAR, NID, DV, NID
IDE, test_cookie


These are essential site cookies, used by the google reCAPTCHA. These cookies use an unique identifier to verify if a visitor is human or a bot.