# ext3 relatime won't boot

## ChrisPage

If I put 

/dev/hda3        /       ext3    relatime                 0 1

I can't boot. It ask for the admin passwd or Contrl-D

But once boot I can mount /dev/hda3 to /mnt/test with relatime.

I can even add

/dev/hda3      /mnt/test         relatime  

to /etc/fstab and it will mount. 

Am I missing something?

I'm running 2.6.21-r4

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## Dan

I may be completely wrong but AFAIK realtime isn't currently a mount option. "man mount"

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## Cheyenne

I believe that it's a kernel option, however mount will have to support the keyword to turn it on

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## Dan

sorry i read realtime not as it is relatime

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## ChrisPage

# mount

...

....

/dev/hda3 on /mnt/test type ext3 (rw,relatime)

It is (I guess) I works for me. But 'man mount' doesn't list it as an option. So I don't know what the deal is.

read this. (This is what got me trying).

http://kerneltrap.org/node/14148

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## Cheyenne

I get an error from mount about an invalid option..

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## ChrisPage

highwind ~ # mount -V

mount: mount-2.12r

highwind ~ # mount -vvvv -t ext3 -o relatime /dev/hda3 /mnt/test/

/dev/hda3 on /mnt/test type ext3 (rw,relatime)

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## Waltarro

I think the option you're looking for is noatime, I'm going

to take a guess and say that you're thinking about the ingo's 

relatime kernel patch that was discussed on kerneltrap earlier

this week.  

  I was curious as well and patched the 2.6.21-gentoo-r4

kernel myself.  It doesn't apply cleanly but is pretty easy to fix.

Anyway Cheyenne is right, if that patch was added it would be 

a kernel option not a mount option.

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## Cheyenne

 *Quote:*   

> 
> 
> ~ $ mount -V
> 
> mount: mount-2.12r
> ...

 

jfs vs ext3 issue? 

Same version of mount -- and I'm running the vanilla sources at  2.6.23-rc1, and checking the source tree relatime is in there.

I might still be missing something really stupid..

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## Cheyenne

 *Waltarro wrote:*   

> 
> 
> Anyway Cheyenne is right, if that patch was added it would be 
> 
> a kernel option not a mount option.

 

Well to a point..

The relatime is a kernel option in that the kernel is the one doing the atime vs noatime vs relatime work itself.  However the mount command is what is used to tell the kernel which option to use.

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## Waltarro

You're probably right I was thinking of this http://people.redhat.com/mingo/relatime-patches/improve-relatime.patch

I'll also add after running with this for a few days its a nice addition to the kernel IO speed wise.

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## depontius

It's time to bump this thread.  I was just reading LWN and saw more mention of relatime, so thought I'd check back.

Support for relatime has been in the kernel since 2.6.20, and improvements are due in 2.6.24.  But it requires support in userspace, in the mount command, part of sys-apps/util-linux.  It looks like the patch was put into util-linux-2.13, and I just did an "ebuild /usr/portage/sys-apps/util-linux/util-linux-2.13-r2.ebuild compile", then did a "strings mount | grep atime" and find "noatime", "nodiratime", and "norelatime".  Incidentally, the same strings check against the stable mount command does not have the "norelatime" or "relatime" option.  Since the result of strings is "norelatime", but I understood the kernel option to be "relatime" I'm not sure what's happening here.  Running "man ./mount.8" shows the option as "relatime", so perhaps it's just a "constant optimization" that gcc knows it can find "*atime" inside "no*atime" for option comparison purposes, for all of the atime options. 

So it looks like you need to be running util-2.13+ if you want "relatime" goodness.  I plan to try this on my laptop a bit later.

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## depontius

I finally got around to setting "=sys-apps/util-linux-2.13-r2 ~x86" in /etc/portage/package.keywords, and tried it out.

Seems to work just fine, accepts "relatime" in /etc/fstab, even for root.

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