Date: Sat, 13 Oct 2001 16:57:34 -0700 From: Peter Wemm <peter@wemm.org> To: Alfred Perlstein <bright@mu.org> Cc: Mikhail Teterin <mi@aldan.algebra.com>, dillon@earth.backplane.com, des@ofug.org, silby@silby.com, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: noatimedir? (Re: cvs commit: src/sys/vm vnode_pager.c) Message-ID: <20011013235734.D6B113810@overcee.netplex.com.au> In-Reply-To: <20011013181245.W59854@elvis.mu.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Alfred Perlstein wrote:
> * Mikhail Teterin <mi@aldan.algebra.com> [011013 14:54] wrote:
> > On 13 Oct, Matt Dillon wrote:
> >
> > > Your particular case may or may not have anything to do with this
> > > bug. If you are running cvsup or running a cvsupd or otherwise
> > > doing things that scan the file tree, mounting with 'noatime' is
> > > the most important thing you need to do.
> >
> > BTW, may be, we want to add something like a noatimedir flag?
>
> That would be a nice addition.
At yahoo, we have a modification to the noatime semantics, that seems quite
a bit more useful..
We have a sysctl (ugh) that sets the maximum atime age of a file at access.
For example, if we set it to 86400 (1 day) then:
open/read a file that has atime < 1 hour ago:
no atime update
open/read a file that has atime < 23 hours ago:
no atime update
open/read a file that has atime > 24 hours ago:
atime gets updated once (and subsequent access will see the atime reset)
This means that we can guarantee a maximum of one atime update per file. It
also means that the atime on a file is always roughly accurate to within a
day. This helps us a lot for archiving files that have not been read for
(say) 3 months.
Ideally this should be a mount option, but that then means that ufs needs
to start taking mount *arguments* (like nfs, with all the nfsargs version
incompatabilities), not just binary flags.
Cheers,
-Peter
--
Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au
"All of this is for nothing if we don't go to the stars" - JMS/B5
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20011013235734.D6B113810>