On Sat, Apr 15, 2006 at 05:31:39PM +0100, Anne Wilson wrote:
> On Saturday 15 April 2006 16:49, stan wrote:
> > On Sat, Apr 15, 2006 at 04:14:29PM +0100, Anne Wilson wrote:
> > > I have a working amanda, now, but I'm not sure that it is optimally set
> > > up. I'm backing up from hda to hdb on the same host, but splitting into
> > > vtapes of 4GB, so that they can be burned onto a DVD.  That part seems to
> > > be working fine.
> > >
> > > What I'm not so sure about is that within each vtape I see the data split
> > > into 10MB chunks, which seems small to me, given the amount of data.  Is
> > > this sensible/desirable?  If not, which parameter is controlling this?
> >
> > I'm pretty certain that is chunksize.
> 
> I did look at that, but two things convinced me that it isn't.  First, the  
> man page says that chunksize is in the 'holding disk' section, and the 
> holding disk is defined as the buffer area, so output wouldn't be in the 
> vtapes.  Second, chunksize is actually defined as 1GB, which is also the 
> default.
> 
> So if it's not that, what else could it be?

Maybe these from the amanda.conf manpage?

tape_splitsize  int

    Default: none. Split dump file on tape into pieces of a
    specified size. This allows dumps to be spread across
    multiple tapes, and can potentially make more efficient
    use of tape space. Note that if this value is too large
    (more than half the size of the average dump being
    split), substantial tape space can be wasted. If too
    small, large dumps will be split into innumerable tiny
    dumpfiles, adding to restoration complexity. A good
    rule of thumb, usually, is 1/10 of the size of your
    tape.

split_diskbuffer string
    Default: none. When dumping a split dump in PORT-WRITE
    mode (usually meaning "no holding disk"), buffer the
    split chunks to a file in the directory specified by
    this option.

fallback_splitsize int
    Default: 10M. When dumping a split dump in PORT-WRITE
    mode, if no split_diskbuffer is specified (or if we
    somehow fail to use our split_diskbuffer), we must
    buffer split chunks in memory. This specifies the
    maximum size split chunks can be in this scenario, and
    thus the maximum amount of memory consumed for
    in-memory splitting. The size of this buffer can be
    changed from its (very conservative) default to a value
    reflecting the amount of memory that each taper process
    on the dump server may reasonably consume.


-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
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