more on fsck with securelevel

TEC Meganet tec at mega.net.br
Sun Jun 6 09:51:03 PDT 2004


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Hi

depending on what you are running on a server I had serious 
performance impacts using fsck in the background (cache server/ 
e-mail) also it seems that fsck -p do not get all when running 
slices with noatime and softupdate and the cache server was not 
completly shut down before shutdown times out. cache or mail 
partitions ever come up as dirty when not shutting the daemon 
completly down before starting shutdown of the system

to prefent eventual problems caused by fast shutdowns I ever set fsck 
- -fy in rc on 4.9

On 5.x you can do so by setting in rc.conf background_fsck=NO and 
fsck -fy in /etc/rc.d/fsck 

You may lose some minutes on boot but get sure that your fs is clean

I think that securelevel settings do not have to do with fsck since 
it seems to be for [u]mount disks, rw access to mem and kmem and 
module loading. Also fsck from rc is run before mount still as 
single user.

hans


On Friday 04 June 2004 20:35, Bill Moran wrote:
> Brooks Davis <brooks at one-eyed-alien.net> wrote:
> > On Fri, Jun 04, 2004 at 05:05:34PM -0500, J.D. Bronson wrote:
> > > I did set this in /etc/rc.conf:
> > > fsck_y_enable="YES"
> > >
> > > But I was wondering if this might be a good idea too:
> > > (looking at the defaults)
> > >
> > > fsck_y_enable="NO"      # Set to YES to do fsck -y if the
> > > initial preen fails.
> > > background_fsck="YES"   # Attempt to run fsck in the
> > > background where possible.
> > > background_fsck_delay="60" # Time to wait (seconds) before
> > > starting the fsck.
> > >
> > > ..might it not be prudent to set 'background_fsck="NO"' when
> > > running in secure mode?
> > >
> > > Eventhough I shut down carefully, sometimes it still feels the
> > > need to run fsck (even with soft updates)...but when running
> > > securelevel, is it actually going to accomplish anything?
> >
> > I think just setting background_fsck_delay=0 may allow bgfsck to
> > work. Once fsck has opened the FS, I think it should keep it
> > open and writes should work.  I'm not 100% sure of that though.
>
> fsck_y_enable determines what happens when a normal fsck fails. 
> If it's set to "NO", you're dumped into single-user mode with a
> scary message.  If it's set to "YES", then fsck is rerun with the
> -y option.  Setting it to "YES" will allow the system to boot
> automatically under almost all conditions, but you may lose data
> that you could have recovered if you'd run fsck manually ...
> assuming you know what you're doing well enough to recover that
> data.
>
> background_fsck controls whether the initial boot fsck is run in
> the background, after booting, or in the foreground during the
> boot, forcing the boot process to wait on it (background_fsck="NO"
> is basically the same behaviour as pre-5 systems)
>
> background_fsck_delay is pretty obvious.
>
> Hopefully, that will help you reach a config that works for you.

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