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Date: Wed, 19 Sep 2001 14:47:25 -0700 (PDT)
From: "Eugene M. Kim" <gene@nttmcl.com>
To: freebsd-gnats-submit@FreeBSD.org
Subject: `noatime' should be discouraged on /var as well
X-Send-Pr-Version: www-1.0

>Number:         30675
>Category:       docs
>Synopsis:       `noatime' should be discouraged on /var as well
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          closed
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          doc-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Sep 19 14:50:00 PDT 2001
>Closed-Date:    Mon Sep 24 00:36:41 PDT 2001
>Last-Modified:  Mon Sep 24 00:37:14 PDT 2001
>Originator:     Eugene M. Kim
>Release:        4.4-RC
>Organization:
NTT Multimedia Communications Laboratories, Inc.
>Environment:
FreeBSD technopolis.nttmcl.com 4.4-RC FreeBSD 4.4-RC #1: Thu Sep 13 23:54:40 PDT 2001     root@technopolis.nttmcl.com:/usr/src/sys/compile/TECHNOPOLIS  i386
>Description:
tuning(7) manpage says that `noatime' mount option should not be used for / and /usr filesystems as some system utilities rely on correct access timestamps.  This should be extended to /var as well, because /var typically contains mailboxes, whose access and modification timestamps are used to determine arrival of new mail.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:

From: Chern Lee <chern@FreeBSD.org>
To: "Eugene M. Kim" <gene@nttmcl.com>
Cc: <freebsd-gnats-submit@FreeBSD.org>
Subject: Re: docs/30675: `noatime' should be discouraged on /var as well
Date: Wed, 19 Sep 2001 17:52:32 -0700 (PDT)

 A quick grep -Ri "atime" /usr/src/contrib/sendmail/ shows that sendmail
 does not use file atime's for any operations.  Mail program often use
 *modification timestamps* (mtime), which is not changed by the noatime
 option.
 
 Generally speaking, mtime is updated every time a file's contents is
 changed, atime is changed whenever a file is accessed.
 
 If my memory serves me correctly, postfix does not make use of atime
 either--I safely run a postfix server with noatime enabled on /var.
 
 - chern
 
 
 

From: "Eugene M. Kim" <gene@nttmcl.com>
To: Chern Lee <chern@FreeBSD.org>
Cc: "Eugene M. Kim" <gene@nttmcl.com>,
	freebsd-gnats-submit@FreeBSD.org
Subject: Re: docs/30675: `noatime' should be discouraged on /var as well
Date: Wed, 19 Sep 2001 19:55:41 -0700

 Chern,
 
 Your observation is correct.  Sendmail does not explicitly manipulate
 the mtime nor the atime.
 
 What happens is, when sendmail has something to deliver to a mailbox, it
 just opens the mailbox file as write-only.  This operation updates only
 the mtime of the mailbox, and its atime is preserved.  Result: the
 mailbox now has an mtime more recent than its atime, which is the
 indication of new mail.
 
 See also tcsh(1), under the description of `mail' variable.
 
 Regards,
 Eugene
 
 A mail-reader resets that condition by reading from the mailbox.  
 On Wed, Sep 19, 2001 at 05:52:32PM -0700, Chern Lee wrote:
 > A quick grep -Ri "atime" /usr/src/contrib/sendmail/ shows that sendmail
 > does not use file atime's for any operations.  Mail program often use
 > *modification timestamps* (mtime), which is not changed by the noatime
 > option.
 > 
 > Generally speaking, mtime is updated every time a file's contents is
 > changed, atime is changed whenever a file is accessed.
 > 
 > If my memory serves me correctly, postfix does not make use of atime
 > either--I safely run a postfix server with noatime enabled on /var.
 > 
 > - chern
 > 
 > 
State-Changed-From-To: open->feedback 
State-Changed-By: murray 
State-Changed-When: Sun Sep 23 18:50:32 PDT 2001 
State-Changed-Why:  
Awaiting updated text from the originator. 


http://www.FreeBSD.org/cgi/query-pr.cgi?pr=30675 

From: murray@stokely.org
To: freebsd-gnats-submit@FreeBSD.org, gene@nttmcl.com
Cc:  
Subject: Re: docs/30675: `noatime' should be discouraged on /var as well
Date: Sun, 23 Sep 2001 18:50:24 -0700

 .. So, can someone provide an example sentence or two that they would
 like to add to tuning(7)?  A diff would be even better.
 
      - Murray
State-Changed-From-To: feedback->closed 
State-Changed-By: murray 
State-Changed-When: Mon Sep 24 00:36:41 PDT 2001 
State-Changed-Why:  
Thanks, Giorgos' patch was applied with minor modifications. 


http://www.FreeBSD.org/cgi/query-pr.cgi?pr=30675 
>Unformatted:
