Solved

noatime on boot disk

Posted on 2001-07-12
6
246 Views
Last Modified: 2012-08-13
I'm developing an embedded system with a flash disk on module root partition mounted in read-only.

Linux keeps on updateing the access time also if it is on a read-only partition. Mounting the partition with the noatime flag solve this problem, but I don't know how to force it at boot time to avoid any kind of remounting once the system is up.

Thank you in advance.
Livio
0
Comment
Question by:livio
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
  • 2
6 Comments
 
LVL 51

Expert Comment

by:ahoffmann
ID: 6280905
add the  noauto  option to the corresponding mount point in /etc/fstab
0
 

Author Comment

by:livio
ID: 6281799
The root partition is mounted by the kernel with its own parameters and not with the /etc/fstab options.

I can modify those parameters with rdev, but I do not know how to force the noatime flag.

Thank you.
0
 
LVL 51

Expert Comment

by:ahoffmann
ID: 6281812
oops, didn't read carefully
> .. disk on module root partition ..

how do you mount this? could you please post the command.
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 5

Expert Comment

by:bryanh
ID: 6282479
I don't get it.  The system is updating atimes (file access times) on a read only filesystem image?  You can't update anything on a read only filesystem image.  What's the filesystem type?  Is this a special filesystem driver for a "flash disk on module root partition" (I had trouble parsing that sentence)?
0
 

Author Comment

by:livio
ID: 6285232
I read on many news on the embedded mailing-lists that the access time keep on to be updated on the ext2 filesystem also if it is mounted in read-only mode.

I'm using the ext2 filesystem to run my emebedded system that has the root partition on a solid state disk made with flash memories ("disk on module"), so I MUST avoid all those unusefull writes.

The "disk on module" is mounted on a normal IDE connector and there is nothing different between it and a normal hard disk from the linux point of view.

I'm using lilo as a boot loader with the read-only option enabled.
0
 
LVL 5

Accepted Solution

by:
bryanh earned 200 total points
ID: 6288295
Hmm.  It certainly doesn't make any sense that the kernel would update the atime on a read only filesystem image.  And in the source code, update_atime() in fs/inode.c, it quite simply ignores the request if the inode is read-only (which in ext2 is always true when the mount is read-only).  And I just accessed a file on a read-only ext2 filesystem image on my Linux 2.2.19.

So I don't know what you and the people on the mailing lists are experiencing.

The read-only option is settable on the initial root filesystem image only as a special case; you can't set any other mount options, such as NOATIME.

I suppose you could make your initial root filesystem a ramdisk (initrd) and then mount the disk-on-module with the NOATIME option via a startup script.
0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
qos on linux 3 110
inotifywait in linux 2 287
Linux , how can I inspect a tar GZ file 3 155
reading values of some parameters from a file in a linux shell script 10 52
The purpose of this article is to fix the unknown display problem in Linux Mint operating system. After installing the OS if you see Display monitor is not recognized then we can install "MESA" utilities to fix this problem or we can install additio…
The purpose of this article is to demonstrate how we can upgrade Python from version 2.7.6 to Python 2.7.10 on the Linux Mint operating system. I am using an Oracle Virtual Box where I have installed Linux Mint operating system version 17.2. Once yo…
Email security requires an ever evolving service that stays up to date with counter-evolving threats. The Email Laundry perform Research and Development to ensure their email security service evolves faster than cyber criminals. We apply our Threat…
Attackers love to prey on accounts that have privileges. Reducing privileged accounts and protecting privileged accounts therefore is paramount. Users, groups, and service accounts need to be protected to help protect the entire Active Directory …

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question