[linux-lvm] LVM2 strangeness.

[Heinz J . Mauelshagen]

On Thu, May 29, 2003 at 04:35:28PM -0700, Max Kalika wrote:
> Quick followup...
> 
> I blew away the snapshots and tried again.  The performance was much better
> (not surprisingly), but I still have lots of "busy buffer" messages in the
> kernel log.  Would anyone know what this is all about, and whether or not I
> should worry about it?

No, they're are caused by our tools syncing LVM metadata and will
disapapear in the next LVM2 release (as Joe mentioned).

> I'm considering putting LVM2 on a production mail
> server, primarily for the simple resize capabilities, but also to use
> snapshots during the rsync process (so as not to get many "file doesn't
> exist" errors).

Go for it :)

Regards,
Heinz    -- The LVM Guy --


> 
> Quoting Max Kalika <max+lists.lvm-dev at lsit.ucsb.edu>:
> 
> > Hello LVM devs and others,
> > 
> > I've been trying to use LVM2 on a backup server for the past few days and
> > I'm seeing some very strange things.
> > 
> > My configuration:
> >   Dell PowerEdge 1300 (800Mhz)
> >   512 MB RAM (2GB swap)
> >   4 120GB IDE (8mb cache) disks in a RAID-5 configuration (on a 3ware
> > card)   Custom built vanilla kernel (2.4.20) with DM patches (0.96.08)
> > applied   LVM2 utilities version 1.95.15
> > 
> > I have a 300GB VG with a 150GB LV on it.  I also have a 50GB snapshot and
> > a 10GB snapshot.  I first rsync all remote server data (8 other machines)
> > to this "holding area" -- where I also hope to have 7 days of snapshot
> > information available on disk.  From here, the latest "current" data gets
> > pushed to tape.
> > 
> > Right now during an rsync of a huge mailstore (lots of small files) from
> > the mail server, the performance on the backup server degrades severly (up
> > to 12 1min load ave. and higher) and I'm seeing lots of the following in
> > the kernel log:
> > 
> >   May 29 14:14:15 butters invalidate: busy buffer
> >   May 29 14:14:15 butters invalidate: busy buffer
> >   May 29 14:14:15 butters invalidate: busy buffer
> >   May 29 14:14:15 butters invalidate: busy buffer
> >   ... on and on and on ...
> > 
> > I'm guessing that most of the cpu is busy copying stuff from the original
> > LV to the snapshots.  Is this a valid assumption?  What can one do to help
> > the situation?  Or do I have a different misconfiguration?  Any light you
> > can shed on this is greatly appreciated.  TIA.
> > 
> > --
> > ---max kalika
> > --max at lsit.ucsb.edu
> > -lsit systems administrator
> > 
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm at sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> 
> 
> ---max kalika
> --max at lsit.ucsb.edu
> -lsit systems administrator
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm at sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

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Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen at Sistina.com                           +49 2626 141200
                                                       FAX 924446
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