[rrd-users] timestamp on rrd files -reg

[Tobias Oetiker]

Hi Andy,

Today Andy Riebs wrote:

> Hi Tobi & Shithal,
>
> > we could work around this by explicitly touching the file after an
> > update ...
>
> Other than for a sys admin's peace of mind, is there any particular
> value in keeping the timestamp up to date?
>
> My concern is that Linux has several commonly-used mount options
> (noatime, relatime) that would prevent `touch` from updating the stats,
> making any work-around even uglier...

I am not aware of any mount option which would prevent a files
last-modification time from being changed when the file is edited
... so this behaviour is definitly odd ...

I have not checked though if the inode change time does not get
modified either. If this is the case, then I would say it is a bug
...

just think of backup software, it normally relies on such
information to determine whether a file should get backuped or not
...

cheers
tobi




>
> /andy
>
> On Thursday 14 August 2008, Tobias Oetiker wrote:
> > Hi Shithal,
> >
> > this is a linux kernel bug (?) where it stopped updatein the file
> > timestamp if files are accessed using memory mapped io ... the same
> > happens to the database files of samba btw ...
> >
> > we could work around this by explicitly touching the file after an
> > update ...
> >
> > opinnions ?
> >
> >
> > cheers
> > tobi
> >
> > Today Shithal TK wrote:
> > > Hello Tobi,
> > >
> > > With the new rrdtool 1.3.1 or 1.3.0 on RHEL5.1  the timestamp of
> > > rrd files are not getting updated though the values are getting
> > > updated in rrd file:
> > > -------------------------------------------------------
> > > Here is an output:
> > >
> > > date: Thu Aug 14 02:56:28 EDT 2008
> > >
> > > timestamp on rrd  when it is created (hecked using ls -l)
> > >
> > > -rw-r--r-- 1 root root 1064 Aug 14 02:56 test.rrd
> > >
> > >
> > > after updating the rrd file at Thu Aug 14 02:59:05 EDT 2008
> > >
> > > rrdtool update test.rrd 1218697140:12345
> > >
> > > -rw-r--r-- 1 root root 1064 Aug 14 02:56 test.rrd
> > >
> > > when we dump it into xml and view that xml file it gives
> > > <lastupdate> 1218697140 </lastupdate> <!-- 2008-08-14 02:59:00 EDT
> > > -->
> > >
> > > But the timestamp is still Aug 14 02:56 test.rrd
> > >
> > > ----------------------------------------------------------
> > >
> > > On the same system when rrdtool-1.2.19 is used I could see the
> > > timestamps on rrd files getiing changed.
> > >
> > > Any reason for what has changed in 1.3.0/1.3.1 that timestamp of
> > > the rrd file is not getting updated?
> > >
> > > Thanks,
> > > Shithal.
> >
> > --
> > Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten,
> > Switzerland http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 /
> > sb: -9900
> >
> > _______________________________________________
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> > rrd-users at lists.oetiker.ch
> > https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
>
>
>
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900