FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > CentOS > CentOS

 
 
LinkBack Thread Tools
 
Old 07-07-2008, 10:35 PM
Robert Moskowitz
 
Default Drive activity every 30sec

I have a Centos installed on a Hitachi 2.5" drive that shuts off really
quickly, it seems.


So every 30 sec, the drive makes the sound of an access activity. I
have looked trying to find what might be being updated. Swap drive
usage is 0 bytes. No activity in /var/log. What might it be and can I
do anything to lessen the drive access (improve battery life)?



_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-07-2008, 10:46 PM
"nate"
 
Default Drive activity every 30sec

Robert Moskowitz wrote:
> I have a Centos installed on a Hitachi 2.5" drive that shuts off really
> quickly, it seems.
>
> So every 30 sec, the drive makes the sound of an access activity. I
> have looked trying to find what might be being updated. Swap drive
> usage is 0 bytes. No activity in /var/log. What might it be and can I
> do anything to lessen the drive access (improve battery life)?

I'm sure there are other things as well but first thing comes to mind is
disabling atime for your file systems, to test the change you can do this

(for each of the mount points)
mount <mount point> -o remount,noatime

e.g.

mount / -o remount,noatime
mount /usr -o remount,noatime

You can verify the options by running 'mount'. If this does the trick
you can add the options to /etc/fstab, e.g.

LABEL=/ / ext3 defaults,noatime
1 1

nate


_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-07-2008, 11:42 PM
Robert Moskowitz
 
Default Drive activity every 30sec

Thanks, but explain...

nate wrote:

Robert Moskowitz wrote:


I have a Centos installed on a Hitachi 2.5" drive that shuts off really
quickly, it seems.

So every 30 sec, the drive makes the sound of an access activity. I
have looked trying to find what might be being updated. Swap drive
usage is 0 bytes. No activity in /var/log. What might it be and can I
do anything to lessen the drive access (improve battery life)?



I'm sure there are other things as well but first thing comes to mind is
disabling atime for your file systems, to test the change you can do this

(for each of the mount points)
mount <mount point> -o remount,noatime


Everything is quite on the notebook front. Now.

But What is going on here?

atime -- Update inode access time for each access. This is the default.

noatime -- Do not update inode access times on this file system (e.g, for
faster access on the news spool to speed up news servers).

Are the inodes being updated or some info about inode access times?

If you have a partition for a mail share, would this help it too (like
it does for a news server)?



e.g.

mount / -o remount,noatime
mount /usr -o remount,noatime

You can verify the options by running 'mount'. If this does the trick
you can add the options to /etc/fstab, e.g.

LABEL=/ / ext3 defaults,noatime
1 1


nate


_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos



_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-07-2008, 11:48 PM
"nate"
 
Default Drive activity every 30sec

Robert Moskowitz wrote:

> But What is going on here?
>
> atime -- Update inode access time for each access. This is the default.
>
> noatime -- Do not update inode access times on this file system (e.g, for
> faster access on the news spool to speed up news servers).
>
> Are the inodes being updated or some info about inode access times?

Every time a file is accessed the file system updates an internal table
noting the last time it was accessed. Used for tools like find. Most
people don't ever use this data themselves directly.

> If you have a partition for a mail share, would this help it too (like
> it does for a news server)?

It should, though there are some apps that don't behave properly without
atime being updated. I don't recall any off the top of my head but recall
discussions over the years where people have mentioned some. Maybe they
are mostly fixed now, I'm sure a google search will turn up results.

This looks informative:
http://kerneltrap.org/node/14148

nate

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-07-2008, 11:50 PM
Robert Moskowitz
 
Default Drive activity every 30sec

nate wrote:

Robert Moskowitz wrote:


I have a Centos installed on a Hitachi 2.5" drive that shuts off really
quickly, it seems.

So every 30 sec, the drive makes the sound of an access activity. I
have looked trying to find what might be being updated. Swap drive
usage is 0 bytes. No activity in /var/log. What might it be and can I
do anything to lessen the drive access (improve battery life)?



I'm sure there are other things as well but first thing comes to mind is
disabling atime for your file systems, to test the change you can do this

(for each of the mount points)
mount <mount point> -o remount,noatime

Oh, I only did this for the mounts in the LVM partition: / and /home

I forgot to do /boot which is a plain old ext3

Still things are quite. This itself is interesting if only ext3 mounts
in LVM partitions not just plain ext3 partitions suffer from this.


OOPS, been 15 min, about, and I just heard the drive seek again. But 15
min I can live with; 30 sec was nerve-racking (on an otherwise silent
system, no fan).



_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-07-2008, 11:51 PM
Florin Andrei
 
Default Drive activity every 30sec

Robert Moskowitz wrote:


I'm sure there are other things as well but first thing comes to mind is
disabling atime for your file systems, to test the change you can do this

(for each of the mount points)
mount <mount point> -o remount,noatime


Everything is quite on the notebook front. Now.

But What is going on here?


It's an old Ext2/3 feature that updates the atime information every time
a file is accessed, even when the file is just being read from, not
written to, thereby transforming even read-only disk operations to
read-write. It's useless in pretty much every situation, except if you
need to do disk forensics (there's a break in and you need to figure out
everything that the attacker did to your system).


There were talks on LKML a while ago to change the default from atime to
noatime. I don't know what was the result of that.


Bottom line: disable atime on all systems unless you _really_ need to do
disk forensics. You will see a performance improvement in almost every
scenario.


--
Florin Andrei

http://florin.myip.org/
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-07-2008, 11:53 PM
"nate"
 
Default Drive activity every 30sec

Robert Moskowitz wrote:
> OOPS, been 15 min, about, and I just heard the drive seek again. But 15
> min I can live with; 30 sec was nerve-racking (on an otherwise silent
> system, no fan).

This may be of help, haven't tried it myself:
http://martin.hinner.info/mybook/spindown.php

Looks like you can get the system to log what causes the drive to spin
up.

nate

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-07-2008, 11:54 PM
Craig White
 
Default Drive activity every 30sec

On Mon, 2008-07-07 at 18:35 -0400, Robert Moskowitz wrote:
> I have a Centos installed on a Hitachi 2.5" drive that shuts off really
> quickly, it seems.
>
> So every 30 sec, the drive makes the sound of an access activity. I
> have looked trying to find what might be being updated. Swap drive
> usage is 0 bytes. No activity in /var/log. What might it be and can I
> do anything to lessen the drive access (improve battery life)?
----
don't use a journalled filesystem (ext3)

Craig

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-08-2008, 12:14 AM
Robert Moskowitz
 
Default Drive activity every 30sec

Craig White wrote:

On Mon, 2008-07-07 at 18:35 -0400, Robert Moskowitz wrote:

I have a Centos installed on a Hitachi 2.5" drive that shuts off really
quickly, it seems.


So every 30 sec, the drive makes the sound of an access activity. I
have looked trying to find what might be being updated. Swap drive
usage is 0 bytes. No activity in /var/log. What might it be and can I
do anything to lessen the drive access (improve battery life)?


----
don't use a journalled filesystem (ext3)
there is a bit to be said about that for a notebook. Particularly if
you separate /home to its own partition. I mean why is /boot a ext3
partition in Centos install? Why not ext2. Perhaps / could be too.
but would you want to put /var/log on a journalling partition? I guess
there have been flames all over the place on these default decisions.



_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-08-2008, 12:28 AM
"nate"
 
Default Drive activity every 30sec

Robert Moskowitz wrote:
> there is a bit to be said about that for a notebook. Particularly if
> you separate /home to its own partition. I mean why is /boot a ext3
> partition in Centos install? Why not ext2. Perhaps / could be too.
> but would you want to put /var/log on a journalling partition? I guess
> there have been flames all over the place on these default decisions.

For most instances, the faster boot times with a journaled file system
after an unclean shutdown is well worth most any downside to using
ext3. I think the fsck code even for ext2 has been improved, before
ext3 was available it was pretty painfully slow though even for small
disks(e.g. 60GB).

/boot probably doesn't need to be ext3, as it's barely ever accessed
after the system boots unless your installing a new kernel or something,
but it doesn't hurt either(as it's hardly ever accessed).

Fortunately for ext3 users you can "convert" the file system to ext2
just by mounting it as ext2 instead of ext3(provided the journal is
flushed out, which should be done when the file system is unmounted).

Though I really can't imagine why anyone would want to use a non
journaled file system these days. Especially on a laptop where the
chance of an unclean shutdown is much higher than that of a server,
hate those fsck times..

nate

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 

Thread Tools




All times are GMT. The time now is 01:28 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org