[linux-lvm] LVM2 strangeness.

Max Kalika max+lists.lvm-dev at lsit.ucsb.edu
Thu May 29 16:49:02 UTC 2003


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




More information about the linux-lvm mailing list