noatime on boot disk

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
livioAsked:
Who is Participating?
 
bryanhConnect With a Mentor Commented:
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
 
ahoffmannCommented:
add the  noauto  option to the corresponding mount point in /etc/fstab
0
 
livioAuthor Commented:
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
Cloud Class® Course: SQL Server Core 2016

This course will introduce you to SQL Server Core 2016, as well as teach you about SSMS, data tools, installation, server configuration, using Management Studio, and writing and executing queries.

 
ahoffmannCommented:
oops, didn't read carefully
> .. disk on module root partition ..

how do you mount this? could you please post the command.
0
 
bryanhCommented:
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
 
livioAuthor Commented:
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
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.