Read-only disk problem

Engineering ee at athyriogames.com
Wed Aug 31 22:34:00 UTC 2011


Thank you very much!

That is what I needed. I have / moutned read only in fstab, but I needed
'root_rw_mount="NO"

To seal the deal

Thanks again!
Sam

-----Original Message-----
From: Peter Jeremy [mailto:peterjeremy at acm.org] 
Sent: Wednesday, August 31, 2011 4:06 PM
To: Engineering
Cc: freebsd-fs at freebsd.org
Subject: Re: Read-only disk problem

On 2011-Aug-30 09:49:41 -0500, Engineering <ee at athyriogames.com> wrote:
>Hi, I've attached some more info. Doing a fsdump shows the following 
>changes over reboot
>
>magic	19540119 (UFS2)	time	Tue Aug 30 03:08:04 2011
>...
>cg 1:
>magic	90255	tell	4b1c000	time	Tue Aug 30 03:08:04 2011
>
>Changes to
>
>magic	19540119 (UFS2)	time	Tue Aug 30 03:13:14 2011
>...
>cg 1:
>magic	90255	tell	4b1c000	time	Tue Aug 30 03:13:14 2011

It's normal for CG's and superblocks to be updated when there's any activity
on a read-write UFS.  (By default, the inode atime field will be lazily
updated when the inode is accessed, so just reading from a UFS mounted RW is
enough to cause writes).

>Is there any data that is written to the disk at boot or mount time, 
>and if so, is there a way to prevent it?

Are you sure that the FS is mounted read-only?  / is automatically mounted
read-write unless 'root_rw_mount="NO"' is specified in /etc/rc.conf.  If a
filesystem is mounted read-only, it will not be updated at all.

--
Peter Jeremy




More information about the freebsd-fs mailing list